Harnessing non-covalent interactions synthesis & catalysis

Faraday joint interest group conference 2023 - Book of abstracts Faraday joint interest group conference 2023

12 - 14 April 2023, York, United Kingdom Harnessing non-covalent interactions for synthesis and catalysis

FDNonCovalent

Book of Abstracts

Registered charity number: 207890

Introduction

Harnessing non-covalent interactions for synthesis and catalysis Faraday Discussion is organised by the Faraday Division of the Royal Society of Chemistry This book contains abstracts of the posters presented at Harnessing non-covalent interactions for synthesis and catalysis Faraday Discussion . All abstracts are produced directly from typescripts supplied by authors. Copyright reserved. Oral presentations and discussions All delegates at the meeting, not just speakers, have the opportunity to make comments, ask questions, or present complementary or contradictory measurements and calculations during the discussion. If it is relevant to the topic, you may give a 5-minute presentation of your own work during the discussion. These remarks are published alongside the papers in the final volume and are fully citable. If you would like to present slides during the discussion, please let the session chair know and load them onto the computer in the break before the start of the session. Faraday Discussion volume Copies of the discussion volume will be distributed approximately 6 months after the meeting. To expedite this, it is essential that summaries of contributions to the discussion are received no later than Friday 21 April 2023 for questions and comments and Friday 5 May 2023 for responses. Posters Posters have been numbered consecutively: P01-P22 A poster session for the in-person posters will take place on Thursday 13 April after the sessions. The posters will be available to view throughout the discussion during all refreshment breaks. During the dedicated poster session, authors should stand with their poster to discuss their research with other attendees.

Poster prize Poster prizes will be awarded best posters as judged by the committee.

Networking sessions There will be regular breaks throughout the meeting for socialising, networking and continuing discussions started during the scientific sessions.

Abstract book sponsors Institute of Process Engineering, Chinese Academy

Scientific Committee

Invited Speakers

Andrew Weller (Chair) University of York, UK

Thomas Ward (Introductory lecture) University of Basel, Switzerland Dean Toste (Closing remarks lecture) University of California, Berkeley, USA Roberto Alonso-Mori SLAC National Accelerator Laboratory, Stanford University, USA

Neil Champness University of Birmingham, UK

Anne Duhme-Klair University of York, UK Paul Raithby University of Bath, UK

Maria Diaz Lopez Diamond Light Source, UK

Joost Reek University of Amsterdam, Netherlands

Sonja Herres-Pawlis RWTH Aachen University, Germany

Adam Kirrander University of Oxford, UK Stuart Macgregor Heriot-Watt University, UK

Tatjana Parac-Vogt, KU Leuven, Belgium

Helma Wennemers ETH Zürich, Switzerland

Faraday Discussions Forum

www.rscweb.org/forums/fd/login.php

In order to record the discussion at the meeting, which forms part of the final published volume, your name and e-mail address will be stored in the Faraday Forum. This information is used for the collection of questions and responses communicated during each session. After each question or comment you will receive an e-mail which contains some keywords to remind you what you asked, and your password information for the forum. The e-mail is not a full record of your question. You need to complete your question in full on the forum. The deadline for completing questions and comments is Friday 21 April 2023 .

The question number in the e-mail keeps you a space on the forum. Use the forum to complete, review and expand on your question or comment. Figures and attachments can be uploaded to the forum. If you want to ask a question after the meeting, please e-maill faraday@rsc.org. Once we have received all questions and comments, responses will be invited by e-mail . These must also be completed on the forum . The deadline for completing responses is Friday 5 May 2023 . Please note that when using the Forum to submit a question or reply, your name and registered e-mail address will be visible to other delegates registered for this Faraday Discussions meeting. Key points: • The e-mail is not a full record of your comment/question. • All comments and responses must be completed in full on the forum Deadlines: Questions and comments Friday 21 April 2023 Responses Friday 5 May 2023

Poster presentations

P01

The photochemistry of cyclopentadiene: theory and simulations Lauren Bertram University of Oxford, UK Optimising artificial enzymes by altering the nature of the active metal complex Rosalind Booth University of York, UK Production of ammonia form air using an electrocatalytic reduction Basheer Chanbasha King Fahd University-KFUPM, Saudi Arabia A photocrystallographic study of packing effects on linkage isomerism Ben Coulson University of Cardiff, UK Photocatalytic polymers: new applications of heterogeneous photocatalysts Calum Ferguson Max-Planck Institute for Polymer Research, Germany Extensive rearrangement of complex fragments during solid/gas single-crystal to single-crystal transformations Joe Goodall University of York, UK Development of phosphinic Brønsted acids for applications in asymmetric catalysis Emily Griffiths Manchester Metropolitan University, UK Robust iridium pincer complexes as a new framework for single-crystal to single-crystal transformations in solid-state organometallic chemistry Matthew Gyton University of York, UK

P02

P03

P04

P05

P06

P07

P08

P09

Supramolecular M 12 L 24 cages for encapsulation of sulfonated photoredox catalysts Rens Ham University of Amsterdam, Netherlands Length-controlled oligomerization with synthetic oligoproline-based templates Bartosz Lewandowski ETH Zürich, Switzerland Advanced microcrystallisation techniques for chemical serial X-ray crystallography Sam Lewis Cardiff University, UK Placing gold on a π+-surface: ligand design and impact on reactivity Wei-Chun Liu Texas A&M University, USA Crystallometrics: a proficient multivariate approach for modelling and prediction of metal complexes properties in the solid state Lorenzo Marchi Università degli studi di Modena e Reggio Emilia, Italy

P10

P11

P12

P13

P14

An ab initio take on dispersion in σ-alkane complexes Carlos Martín Fernández Heriot-Watt University, UK

P15

A Co(TAML)-based artificial metalloenzyme for asymmetric group transfer catalysis Eva Meeus University of Amsterdam, Netherlands Multidentate halogen-bond based catalysis: a computational study Nika Melnyk Trinity College Dublin, Ireland Investigating new photoactive ferroelectrics using dynamic X-ray diffraction techniques Josh Morris Cardiff University, UK

P16

P17

P18

Dicoordinate Au(I)–ethylene complexes as hydroamination catalysts Miquel Navarro CSIC - Universidad de Sevilla, Spain Harnessing non-covalent interactions for peptide encapsulation within metal-organic materials Imogen Riddell The University of Manchester, UK Exploiting non-covalent interactions in polymerization catalysis: highly active aluminum catalysts for ring-opening polymerization Charles Romain Imperial College London, UK Non-covalent interactions in σ-alkane complexes of Rh in solid state microenvironments based on [BArF 4 ] and [S-BArF 4 ] anions M. Arif Sajjad Heriot-Watt University, UK Ionic interactions enable stereoselective access to mechanically planar chiral rotaxanes Ye Zhu National University of Singapore, Singapore

P19

P20

P21

P22

The photochemistry of cyclopentadiene: theory and simulations Lauren Bertram 1 , Peter M. Weber, 2 Adam Kirrander 1 1 University of Oxford, UK, 2 Brown University, USA Cyclopentadiene (CP) is an interesting target for studies of ultrafast photochemical reactions in conjugated polyenes. It forms two highly ring strained and energetically unfavourable photoproducts, bicyclo[2.1.0]pentene (BP) and tricyclo[2.1.0.0 2,5 ]pentane (TP), via electrocyclic ring closure. In addition, previous experiments also suggest that it can undergo a 1,3-sigmatropic hydrogen shift 1 and that there is a thermal back reaction from BP to CP on long time scales. To investigate this further, we have simulated the nonadiabatic photochemistry of CP 2 using semiclassical surface-hopping with XMS(3)-CASPT2(4,4) electronic structure theory, continuing the simulations on the ground state using DFT/PBE0 until 10 ps after excitation. A mixture of hot CP and BP is observed, on a short-time scale, and on a longer-time scale a slow conversion from BP to CP, with the latter further modelled using RRKM theory. Finally, observables for ultrafast x-ray scattering experiments are calculated in anticipation of future experiments that map the structural dynamics of the reaction. 3 The prospect of retrieving the nature of the electronic states from such experiments is also discussed. 4 References 1. W. Fuß, W. E. Schmid and S. A. Trushin, Chem. Phys. , 2005, 316 , 225. 2. T. S. Kuhlman, W. J. Glover, T. Mori, K. B. Møller and T. J. Martinez, Faraday Disc. , 2012, 157 , 193. 3. H Yong, et al., Proc. Nat. Acad. Sci. , 2021, 118 , e2021714118. 4. H Yong, et al., Nat. Comm. , 2020, 11 , 1-6.

P01

Optimising artificial enzymes by altering the nature of the active metal complex Rosalind Booth, L Gečiauskas, A. Miller, G. Grogan, K.S. Wilson, A-K Duhme-Klair University of York, UK Artificial metalloenzymes can enhance the catalytic capabilities of transition metal catalysts by contributing a complex network of complementary interactions by introducing a protein scaffold. 1,2 Several approaches to designing artificial metalloproteins are being investigated, with catalytically active metal sites being incorporated into proteins by a variety of methods. Our design utilizes a small protein involved in the iron-uptake pathway in some microorganisms. 3 By attaching a catalytically-active metal complex to an iron chelator, we can position the catalyst inside our protein scaffold. An iridium transfer hydrogenation catalyst was selected to target imine reduction, and in combination with our artificial metalloenzyme design initially achieved moderate catalytic rate and selectivity. Through tuning of the steric and electronic properties of the iridium-coordinating ligands, both the selectivity and catalytic rate of the reaction were improved. In addition, the uses of similar thermophilic proteins have further enhanced artificial metalloenzyme performance.

References 1. J. Collot, J. Gradinaru, N. Humbert, M. Skander, A. Zocchi and T. R. Ward, J. Am. Chem. Soc., 2003, 125 , 9030-9031. 2. F. Schwizer, Y. Okamoto, T. Heinisch, Y. Gu, M. M. Pellizzoni, V. Lebrun, R. Reuter, V. Köhler, J. C. Lewis and T. R. Ward, Chem. Rev. , 2018, 118 , 142-231. 3. D. J. Raines, J. E. Clarke, E. V. Blagova, E. J. Dodson, K. S. Wilson and A-K. Duhme-Klair, Nature Catalysis , 2018, 1 , 680- 688.

P02

Production of ammonia form air using an electrocatalytic reduction Basheer Chanbasha King Fahd University, Saudi Arabia In ambient circumstances, electrocatalytic N 2 reduction to NH 3 is an appealing approach for artificial N 2 fixation. Electrochemical nitrogen reduction reactions can offer a useful source of ammonia, but the process is limited by the low production rate and poor conversion efficiency at the cathodic electrode. Here, we have designed a unique iron oxide for the electro-reduction of nitrogen to ammonia in a neutral electrolyte and mild conditions, achieving excellent faradic efficiency and a high ammonia yield rate of 35.6 g h1 mg1 cat, at1.0 V. The C-Fe 2 O 3 on graphite felt (Fe 2 O 3- C@GF) was synthesized hydrothermally under a nitrogen environment for the electrochemical reduction of nitrogen. Graphite is used as a substrate due to its supermicropores, which function as a more active site for Fe 2 O 3 to be exposed. Due to the supermicropore nature of the graphite felt substrate, more active sites of C-Fe 2 O 3 could be exposed, increasing electron transport and creating open pathways for rapid H 2 release. These findings can support the development of Fe-based electrocatalysts for NRR at atmospheric pressure. References 1. The author acknowledges the funding support provided by the Deanship of Research Oversight and Coordination at the King Fahd University of Petroleum and Minerals through project no ER221003.

P03

A photocrystallographic study of packing effects on linkage isomerism Ben Coulson and Lauren Hatcher Cardiff University, UK Linkage photoisomerism is a phenomenon whereby transition metal complexes alter the coordination mode of a ligand upon interaction with light. This process can be characterised using photocrystallography, whereby single crystals of photoactive complex are irradiated during x-ray diffraction measurements to observe the nature and extent of the isomerism present. 1, 2

Figure 1: Linkage photoisomerism in nitro-complex of metal [M] Linkage photoisomerism occurs in certain metal-nitro complexes, wherein the nitrogen-bound nitro- ligand isomerises to the metastable oxygen-bound nitrito- mode (Figure 1). A family of novel palladium nitro- complexes has been synthesised by varying the functionality of an ester group distant from the metal centre. It is demonstrated that chemically altering these distant moieties has little impact on the electronics of metal centre in the solution state. However, adjusting the molecular shape impacts molecular packing in the crystal state, which in turn alters the photophysics of the system in the solid state. By varying temperature and irradiance, the kinetic stability of the metastable state has been investigated for each compound. Crystal data is then used as a basis to simulate the systems and visualise the mechanism of the isomerism process. It is suggested that the geometry change caused by linkage photoisomerism may be translatable into an induced dielectric dipole if used to change the steric environment of an within a suitable host material. Metal-organic frameworks (MOFs) are ordered, porous structures containing metal nodes and organic struts surrounding uniform pores. Novel MOF materials have been synthesized containing the palladium moieties already studied in molecular systems, and the implications of the results gained from molecular systems are considered in the context of utilising linkage photoisomerism as a pathway to control macroscopic properties. References 1. Hathaway, G. Crevatin, D. Omar, B. H. Williams, B. A. Coulson, C. C. Wilson and P. R. Raithby, Communications Chemistry , 2022, 5 , 102. 2. P. Coppens, I. Novozhilova and A. Kovalevsky, Chem Rev , 2002, 102 , 861-884.

P04

Photocatalytic polymers: new applications of heterogeneous photocatalysts Calum Ferguson 1,2 , Julian Heuer 1 , Rong Li 1 , Katharina Landfester 1 1 Max-Planck Institute for Polymer Research, Germany, 2 University of Birmingham, UK Controlling the outcome of catalytic reactions, by designing the catalytic material, allows highly efficient chemical reactions to be undertaken. Selective catalysis has recently been targeted to efficiently produce high-value products, where both selectivity for reagents and products is required. Nature’s catalysts, enzymes, are often extremely selective, where only one reagent is reacted to produce a distinct product. Here, the physical properties of these macromolecular biomaterials dictate which specific substrate can be transformed. Our research looks to produce synthetic catalytic systems that also utilizes a similar approach to nature to embed some selectivity into the catalytic material. Controlling the local hydrophobicity/hydrophilicity of a catalytic center allowing a greater proximity of a desired substrate to the active center. To achieve this, the location of the active center within a macromolecular structure needs to be precisely controlled. Furthermore, a defined active catalytic center is required, where the reaction will proceed. To achieve this molecular photocatalysts are modified with vinyl groups, and copolymerized into well- defined polymer structures. These photocatalytic polymers were synthesized by RAFT-PISA, which results in self-assembled amphiphilic photocatalytic polymers with a micellar like structure. Here the location of the photocatalyst was differed between the hydrophilic and hydrophobic portion of the polymer. The differences in hydrophobicity/hydrophilicity between these two distinct environments resulted in dramatic changes in reaction rates of different substrates, which could be correlated to the partition coefficient of the substrate. Both reductive and oxidative reactions where investigated with a broad substrate scope to confirm the trends observed. Furthermore, the hydrophobic environment could be further modified by adding a secondary solvent to swell the polymeric micelles. This resulted in vastly different reaction rates and, interestingly, could be used to selectively tune the reaction product. References 1. ACS Appl. Mater. Interfaces2023, 15, 2, 2891–2900

P05

Extensive rearrangement of complex fragments during solid/gas single-crystal to single-crystal transformations Joe Goodall, Andrew Weller, E.A. Thompson, L. R. Doyle, M.R. Gyton, H.T. Jenkins, J.M. Lynam University of York, UK The use of organometallic solid-state single-crystal to single-crystal (SC-SC) transformations is an emerging area of synthesis, reactivity and catalysis. 1, 2 A recurring problem with SC-SC transformations is that preservation of crystallinity throughout the transformation is often challenging due to the stress associated with the reaction. 1, 3 Here, the solid-state rearrangements during solid/gas reactions of manganese(I) and rhenium(I) pincer complexes with CO is shown to be highly dependent on the non-covalent interactions between the incoming ligand and the weakly coordinating anion. The reactions cause the crystals to undergo extensive cracking to form micron-sized crystals, which necessitated the use of microcrystal Electron Diffraction (microED) 4 for structural elucidation in the case of the manganese example. This report highlights the extreme plasticity of the solid-state, facilitated by the [BAr F 4 ] - anions and associated non-covalent interactions, as well as the capability of microED to facilitate structure determination of the products of solid/gas SC-SC reactions where macroscopic crystalline integrity is lost.

Figure 1: Solid-state rearrangement of [Mn( i Pr-PONOP)(THF)(CO) 2 ][BAr F

4 ] upon addition of CO in a single-crystal to single-

crystal transformation. References 1. K. A. Reid and D. C. Powers, Chem. Commun. , 2021, 57 , 4993-5003. 2. A. J. Martínez-Martínez, C. G. Royle, S. K. Furfari, K. Suriye and A. S. Weller, ACS Catal. , 2020, 10 , 1984-1992. 3. A. J. Bukvic, A. L. Burnage, G. J. Tizzard, A. J. Martínez-Martínez, A. I. McKay, N. H. Rees, B. E. Tegner, T. Krämer, H. Fish, M. R. Warren, S. J. Coles, S. A. Macgregor and A. S. Weller, J. Am. Chem. Soc. , 2021, 143 , 5106-5120. 4. C. G. Jones, M. W. Martynowycz, J. Hattne, T. J. Fulton, B. M. Stoltz, J. A. Rodriguez, H. M. Nelson and T. Gonen, ACS Cent. Sci. , 2018, 4 , 1587-1592.

P06

Development of phosphinic Brønsted acids for applications in asymmetric catalysis Emily Griffiths , Ryan Mewis, Beatrice Macia-Ruiz, Vittorio Caprio, Andrew Caffyn Manchester Metropolitan University, UK 1,1’-binaphthalene-2,2’-diol (BINOL) phosphine-based Brønsted acids are important acid catalysts. BINOL- derived chiral phosphoric acids are useful organocatalysts for a range of transformations e.g. reductive aminations, Diels–Alder and cascade reactions. Excellent enantioselectivities are readily obtainable. The Brønsted acid strength dictates the success of these ligands and thus has a direct effect on the catalytic potential of these acids. The strength of a Brønsted acid can be significantly increased by the presence of fluorine atoms near the acidic site. This work is focused on the production of a fluorinated Brønsted acid which is phosphinic based. It is hypothesised that the increased acidity will yield higher conversions whilst retaining enantioselectivity. We have synthesised the fluorinated acid and its pK a was determined to be significantly more acidic than the parent Bronsted acid (pK a of 8.44 vs 3.37 – the former is RR’(CF 2 ) 2 PO(OH) whereas the latter is RR’O 2 PO(OH)). The fluorinated phosphinic acid was synthesised through a seven-step synthesis from BINOL. The overall yield for the synthesis was 60%. The synthetic steps can be reduced from seven to five by treatment of 1,1’-binaphthalene- 2,2’-dimethyl to the corresponding phosphonate ester. This circumvents two synthetic steps, thus shortening the synthetic procedure considerably and increasing the throughput to latter reactions. We showcase this synthetic transformation as part of our presentation. The pK a of the fluorinated Brønsted acid was determined through the use of titrimetric 19 F NMR spectroscopy. The approach is based on that reported by Jeannerat et. al. 1 Two sulfonyl amide compounds (of the type PhSO 2 NHSO 2 (C 5 F 5 )) were used as reference standards which differed in the position of the nitro group on the non-fluorinated aromatic ring (4-NO 2 = 1 and 3-NO 2 = 2 ). The pK a determined through employment of each reference compound was 8.33 for 1 and 8.54 for 2 . The approach was validated by independently validating the pK a ’s of the two reference compounds and comparing against reported literature values. These were determined to be 6.61 for 1 (literature pK a = 6.60) and 6.72 for 2 (literature pK a = 6.73). To assess the catalytic potential of the fluorinated Brønsted acid prepared, a Friedel-Crafts reaction has been considered. The parent non-fluorinated Brønsted acid has been used as a control as well as other Brønsted acids bearing, for example, 2,4,6-triisopropylphenyl (TRIP) groups. These Brønsted acids have a range of pK a values and therefore comparison of product yields under the same conditions enable the direct affect of pK a on yield to be shown. References 1. R. Shivapurkar and D. Jeannerat, Analytical Methods , 2011, 3 , 1316-1322

P07

Robust iridium pincer complexes as a new framework for single-crystal to single-crystal transformations in solid-state organometallic chemistry Matthew Gyton, Simon B. Duckett and Andrew S. Weller University of York, UK Considerable advances have been made over the past decade in Solid-State Organometallic Chemistry (SMOM); this is best illustrated by the facile isolation and solid-state stability of the σ-alkane complex [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(norbornane)][BAr F 4 ] through the solid/gas hydrogenation of [Rh(Cy 2 PCH 2 CH 2 PCy 2 ) (norbornadiene)][BAr F 4 ]. 1 Critical to the stability of this complex in the solid state is the octahedral packing of the tetraarylborate [BAr F 4 ] anions that provides a rigid crystalline framework around the cationic metal centre that stabilises the weak metal-alkane interaction with supporting non-covalent interactions. This approach has allowed the extension of the series with wider bite-angle phosphines (Cy 2 P(CH 2 ) n PCy 2 , n = 3-5) afford similar polyhedral packing of the anion around the cation and similar stabilizing non-covalent interactions. 2 Recent efforts have focused on the extension of these solid/gas SMOM methods of synthesis to more varied ligand frameworks and metal centres beyond this now well-established chelating diphosphine manifold. Initial investigations have targeted complexes such as [Ir(PONOP iPr )(propene)][BAr F 4 ], in which the crystalline solid-state microenvironment gates reactivity by preventing propene insertion into an iridum hydride, which directly contrasts with observed solution phase behaviour. 3 This study seeks to extend this approach further through the use of a solid-state stable but solution-state dynamic and highly reactive complex [IrHMe(PONOP tBu )] [BAr F 4 ]. This pincer ligand framework provides cations of sufficient stability to afford facile, sequential transformations as single-crystalline materials. Discussion will focus on the solid/gas single-crystal transformations under thermal conditions and investigations into the differences in dynamics observed in the solid state.

Figure 1. The solid/gas reaction of [IrHMe(PONOP tBu )][BAr F

4 ] with: i) dihydrogen affording single crystalline [Ir(H) 2 (PONOP tBu )]

[BAr F 4 ] and subsequently ii) carbon monoxide to afford single crystalline [Ir(CO)(PONOP tBu )][BAr F 4 ]. References 1. S. D. Pike, F. M. Chadwick, N. H. Rees, M. P. Scott, A. S. Weller, T. Krämer and S. A. Macgregor, J. Am. Chem. Soc. , 2015, 137 , 820–833. 2. A. J. Martínez-Martínez, B. E. Tegner, A. I. McKay, A. J. Bukvic, N. H. Rees, G. J. Tizzard, S. J. Coles, M. R. Warren, S. A. Macgregor and A. S. Weller, J. Am. Chem. Soc. , 2018, 140 , 14958–14970. 3. C. G. Royle, L. Sotorrios, M. R. Gyton, C. N. Brodie, A. L. Burnage, S. K. Furfari, A. Marini, M. R. Warren, S. A. Macgregor and A. S. Weller, Organometallics , 2022, 41 , 3270–3280.

P08

Supramolecular M 12 L 24 cages for encapsulation of sulfonated photoredox catalysts

Rens Ham and Joost N.H. Reek University of Amsterdam, Netherlands

The use of visible light to drive chemical reactions is an attractive way to transform current heat-driven processes towards more sustainable ones. Therefore, in the past decade, photoredox catalysis has become an attractive methodology for chemical research. 1 Due to the facile and mild introduction of open shell species to organic molecules, new reaction intermediates and outcomes become possible. However, obtaining selective products is inherently difficult due to the radical-type reactivity and the photoredox protocol is often limited to long-lived- excited (triplet) state photocatalysts. An attractive way to ensure close proximity between photocatalyst and substrate are the use of supramolecular coordination cages. 2 In their single cavities, photocatalyst and substrate can be preorganized which may result in facilitated photoinduced electron transfer (PET) and provides a platform for more selective photoredox reactions. By exploiting the strong interaction between guanidinium and sulfonate groups, 3 sulfonated derivatives of model photocatalysts such as Ir(ppy) 3 may be encapsulated inside the cavity of M 12 L 24 -type guanidinium cages. 4 We study the binding and photophysical properties of these host–guest systems and evaluate them for photoredox decarboxylation reactions. References

1. Overman, L.E. Chem. Rev. 2022 , 122 , 1717–1751. 2. Reek, J.N.H. Chem Rev. 2023 , XXX , XXX–XXX. 3. Reek, J.N.H. Nat. Chem. 2016 , 8, 225–230. 4. Wenger, O.S. Kerzig, C. J. Am. Chem Soc. 2020 , 142 , 10468–10476.

P09

Length-controlled oligomerization with synthetic oligoproline-based templates Bartosz Lewandowski, R. Schäfer, S. Loosli, D. Harangozo, H. Wennemers ETH Zürich, Switzerland Templated synthesis is a highly valuable strategy for length-controlled preparation of oligomers. 1,2 Such reactions, however, typically require stoichiometric amounts of the template with respect to the product. 3 Recently, we reported catalytic macrocyclic templates which promote the formation of oligomers of a small molecule substrate with a remarkable degree of length-control. 4 The templates consist of rigid oligoproline moieties decorated with catalytic sites at defined distances on both sides of the macrocyclic cavity. The dimension of the macrocycle and the number of catalytic moieties thereon determine the number of monomers that are incorporated into the growing oligomer in the templated process. Building on these findings we wanted to develop linear templates for catalytic length-controlled oligomerization. Such linear templates would be less complex and thus easier to access and modify, e.g. by extension of the length, than macrocyclic templates. We envisioned that the linear template for length-controlled oligomerization needs to contain a recognition site for an “ initiator ” building block and activation sites that allow for the activation of the initiator and incoming “ propagator ” building blocks (Fig.1a). The initiator should contain a binding site (Fig.1a, green) that binds to the recognition site of the template. Additionally, the initiator needs a functional group (Fig.1a, blue) that can be activated by the activation site on the template for reaction with the reactive site of the propagator. The propagator should contain the reactive site (Fig.1a, brown) as well as the same activatable functional group as the initiator. Upon binding of the initiator to the template (step 1) a series of propagation reactions (steps 2,3) will allow for incorporation of propagator building blocks to the growing oligomer. These reactions will continue until the last activation site at the end of the template is reached. Consequently, the length of formed oligomer will correlate with the number of activation sites on the template (Fig.1b).

Fig.1a) Design of linear templates; b) Theoretical correlation between the length of the template and the formed oligomer. We will present our initial efforts towards the development of linear oligomerization templates, following the above design considerations. Specifically we will discuss systems were the initiator is bound to the template by a dynamic covalent bond thus preventing the dissociation of the oligomer and allowing us to focus on optimizing the propagation reactions. References 1. K. Josephson, M. C. T. Hartman, J. W. Szostak, J. Am. Chem. Soc. , 2005, 127 , 11727–11735; 2. J. Niu, R. Hili, D. Liu, Chem. , 2013, 5 , 282–292. 3. M. C. O'Sullivan, J. K. Sprafke, D. V. Kondratuk, C. Rinfay, T. D. W. Claridge, A. Saywell, M. O. Blunt, J. N. O’Shea, P. H. Beton, M. Malfois, H. L. Anderson, Nature , 2011, 469 , 72-75; 4. D. Núñez-Villanueva, M. Ciaccia, G. Iadevaia, E. Sanna, C. A. Hunter, Chem. Sci. , 2019, 10 , 5258–5266. 5. X. Li, D. Liu, Angew. Chem. Int. Ed. , 2004, 43 , 4848–4870.B. Lewandowski, D. Schmid, R. Borrmann, D. Zetschok, M. Schnurr, H. Wennemers, Nat. Synth ., in press .

P10

Advanced microcrystallisation techniques for chemical serial X-ray crystallography Sam Lewis 2 , Lauren E. Hatcher 1 , Mark R. Warren 2 , Kenneth D.M. Harris 1 1 Cardiff University & Diamond Light Source, UK and 2 Cardiff University, UK Serial X-ray crystallography (SX) is a method by which structural determination can be achieved through the combination of still images recorded from tens of thousands of individual crystals. This technique is of particular interest to systems that are susceptible to X-ray induced damage at synchrotron or XFEL light sources. This is a problem which will only grow in prevalence with the rise of more intense light sources. Although SX methods have largely seen widespread use in characterizing biological samples, there is now a growing interest in the application of SX for chemical systems. The main bottleneck for SX is the production of microcrystal batches with suitable size and a narrow crystal size distribution. Previously, sample preparation for SX applications has utilized inefficient and wasteful post- processing steps to achieve the required batches, so the control of primary crystallization conditions to produce crystal batches in a single step is the ultimate goal. The system sodium nitroprusside (Na 2 [Fe(CN) 5 (NO)]·H 2 O, SNP) was selected due to its commercial availability and previous usage in photocrystallography studies, which would enable further SX method development opportunities. 1 Unfortunately, SNP tends towards distinctive needle- like habits, thus there is also a need to modify the habit to achieve more desirable block or plate habits. 2 A range of different solvent systems have been screened through a range of classical crystallization techniques for desirable habits. Although only a single polymorph is reported for SNP, novel desirable crystal habits have been observed in drop-casting techniques. These unstable habits undergo a period of growth followed by dissolution and transformation upon further solvent evaporation into the characteristic needle habit. These initial observations have been incorporated into a data-driven approach for obtaining desirable habits of SNP. It is hoped that insights from this work will contribute to a general workflow, which will simplify sample preparation for SX analysis and enable more widespread use of the technique. References 1. M. D. Carducci, M. R. Pressprich and P. Coppens, Journal of the American Chemical Society , 1997, 119 , 2669-2678. 2. P. Manoharan and W. C. Hamilton, Inorganic Chemistry , 1963, 2 , 1043-1047.

P11

Placing gold on a π+-surface: ligand design and impact on reactivity Wei-Chun Liu and François Gabbaï Texas A&M University, USA As part of our continuing interest in modulating the reactivity of late-transition metal complexes, we have developed a series of gold chloride complexes supported by ambiphilic phosphine ligands featuring a xanthylium cation as the electron poor unit. In this presentation, I will describe a novel type of gold chloride complex in which AuCl moiety interacts with π+ surface of the xanthylium cations as indicated by structural studies. Energy decomposition analyses carried out on a model system indicates the prevalence of non-covalent interactions in which the electrostatic and dispersion terms cumulatively dominate. The presence of these AuCl–π + interactions correlates with the high catalytic activity of this complex in the cyclisation of 2-(phenylethynyl)phenylboronic acid, N-propargyl-t-butylamide, and 2-allyl-2-(2-propynyl)malonate. The presentation will end by a comparison of the catalytic reactivity of the xanthylium complex with its significantly less active acridinium and the 9-oxa- 10-boraanthracene analogues. References 1. Chem. Sci. , 2023 , 14 , 277-283 2. Chem. Commun. 2021 , 57 , 10154-10157. 3. Chem. Sci. 2021 , 12 , 3929-3936. 4. Angew . Chem. Int. Ed. 2019 , 58 , 18266-18270.

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Crystallometrics: a proficient multivariate approach for modelling and prediction of metal complexes properties in the solid state Lorenzo Marchi 1 , Serena Maria Fantasia, 2 Marina Cocchi, 1 Luca Rigamonti 1 Università degli studi di Modena e Reggio Emilia, Italy, 2 F. Hoffmann-La Roche Ltd, Switzerland Iron(II) and cobalt(II) complexes of general formula [M(bpp-R) 2 ](X) 2 ×solv with R-substituted bis -pyrazolilpyridyl (bpp-R) ligands (M = Fe, Co; X − = anion; solv = co-crystallized solvent) possess magnetic properties of interest. Iron(II) derivatives have been deeply studied for their ability to undergo spin transition from high spin ( S = 2, HS) to low spin ( S = 0, LS) state, showing the spin crossover (SCO) phenomenon. 1,2 Cobalt(II) compounds, much less studied, can behave as single-molecule magnets (SMMs) with consequent slow relaxation of the magnetization at low temperature. 3 Thanks to the fact that HS iron(II) complexes can be isostructural to the analogue cobalt(II) complexes, 2,3 it is possible to take advantage of the structural data available on iron(II) derivatives for harnessing non-covalent interactions and use the extracted information for the synthesis of new cobalt(II) complexes with desired modulated structures. The intermolecular interactions and the crystal packing among the substituent R of the bpp ligands, the anion X − and the co-crystallized solvent, if present, which govern the distortion of the octahedral coordination environment around the metal centre and hence their magnetic behaviour, are here studied with an innovative multivariate approach through the help of chemometrics tools. At first, an exploratory Principal Component Analysis (PCA) was conducted using coordination bond distances, angles and selected torsional angles of the available X-ray structures of HS iron(II) complexes as probes of the intermolecular contacts in the solid state. This leads to a model able to distinguish among the SCO complexes and the HS-blocked ones, justifying the validity of our multivariate approach to study non-covalent interactions in the solid state. 4 In this model cobalt(II) known structures were projected, finding a close-fitting connection with the corresponding iron(II) structure. This points out which new cobalt complexes should be synthetically pursued to explore the PCA space and the most diverse complexes. This general chemometrics approach can be easily extended to other complexes and other properties such as catalysis. References

1. M. Halcrow et al., Inorg. Chem. , 2019, 58 (15), 9811–9821. 2. N. Bridonneau et al., Dalton Trans. , 2017, 46 (12), 4075– 4085. 3. L. Rigamonti et al., Chem. Eur. J. , 2018, 24 (35), 8857–8868. 4. L. Marchi et al., Inorg. Chem. Front. , 2023, submitted .

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An ab initio take on dispersion in σ-alkane complexes Carlos Martín Fernández, M. Arif Sajjad, S. A. Macgregor Heriot-Watt University, UK

Amongst the many tools that have been developed for the analysis of non-covalent interactions [1], Energy Decomposition Analyses (EDAs) have proven to be of great use. Nonetheless, the different flavours of EDAs can show some differences in the way that the energy is partitioned, and so might provide different answers to the same problem. Other important issues have to do with the level of theory at which the energy terms are calculated and with the ability of the EDA to cover from weak to strong interactions [2]. Recently, a local energy decomposition analysis (LED) based on the DLPNO-CCSD(T) method has been developed and applied to a wide range of systems [3, 4]. Importantly, this method uses energies calculated at a high level of theory and can describe interactions at any range from the weak-strong continuum. Moreover, it can provide a formally well-founded definition of all the different terms in the energy partition, which is particularly interesting regarding its description of London dispersion contributions.

Figure 1 . The two σ-alkane complexes under study, highlighting the interaction with one of the six neighbouring [BAr F 4 ] anions. Note the widely different stabilities. In this work, we will apply such LED analysis to two important σ-alkane complexes (Fig. 1) that have been thoroughly characterized both experimentally and with the aid of computational tools [5-7]. Previously, intramolecular interactions between the NBA (norbornane, C 7 H 12 ) and the {RhP 2 } fragment in [1-NBA] + have been assessed with LED methods [8]. Here we consider intermolecular non-covalent interactions between the cations and the surrounding anions, thus taking into account the effect of the crystal environment. Due to the large system size, special attention will be paid to the details of the calculation in order to yield both accurate and meaningful results. References 1. E.Pastorczak and C. Corminboeuf, J. Chem. Phys. 2017 , 146 , 120901. 2. J.Andrés, P. W. Ayers, R. A. Boto et al. J. Comput. Chem . 2019 , 40 , 2248–2283. 3. G.Bistoni, WIREs Comput Mol Sci . 2020 , 10 , e1442. 4. W.B. Schneider, G. Bistoni, M. Sparta, et al. J. Chem. Theory Comput., 2016 , 12 , 4778–4792.

5. S.D. Pike, A. L. Thompson, A. G. Algarra, et al. Science 2012 , 337 , 1648–1651. 6. A.G. Algarra, A. L. Burnage, M. Iannuzzi, et al. Struct. Bond. , 2020 , 186 , 183–228. 7. A.J. Bukvic, A. L. Burnage, G. J. Tizzard, et al. J. Am. Chem. Soc. 2021 , 143 , 5106–5120. 8. Q. Lu, F. Neese and G. Bistoni, Phys. Chem. Chem. Phys. , 2019 , 21 , 11569–11577.

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A Co(TAML)-based artificial Metalloenzyme for asymmetric group transfer catalysis Eva Meeus 1 , Nico V. Igareta 2 , Iori Morita 2 , Thomas R. Ward 2 , Bas de Bruin 1 , Joost N.H. Reek 1 1 University of Amsterdam, Netherlands, 2 University of Basel, Switzerland Second coordination sphere effects are crucial for the function of enzymes and hence laid the foundation for an intensive and thriving area of research devoted to catalysis in confined spaces. For instance, transition metal complexes can be placed inside synthetic cages to control their catalytic properties. Alternatively, encapsulation inside a protein also affords a well-defined secondary coordination sphere. The resulting artificial metalloenzyme offers means to optimize selectivity and activity towards a desired reaction. In this work, we incorporated a biotinylated Co(TAML)-complex (TAML = Tetra Amido Macrocyclic Ligand) into streptavidin (Sav) to assemble an artificial metalloenzyme, which is active in oxygen atom transfer to aromatic olefins. After careful characterization of the host–guest system, initial screening of the Sav library—that included (double) mutations at the positions Sav S112X and Sav K121X—demonstrated a positive effect on the selectivity, which is otherwise not achieved in absence of the protein. Hence, the Co(TAML)-catalyst proves amenable to the design and optimization of an artificial metalloenzyme active in asymmetric group transfer catalysis, by means of the biotin-streptavidin technology. References 1. E.J. de Vries, D.B. Janssen, Curr. Opin. Biotechnol. 2003 , 14, 414–420. 2. N.P. van Leest, M.A. Tepaske, J.-P.H. Oudsen, B. Venderbosch, N.R. Rietdijk, M.A. Siegler, M. Tromp, J.I. van der Vlugt, B. de Bruin, J. Am. Chem. Soc. 2020 , 142, 552−563. 3. F. Schwizer, Y. Okamoto, T. Heinisch, Y. Gu, M.M. Pellizzoni, V. Lebrun, V. Köhler, J.C. Lewis, T.R. Ward, Chem. Rev . 2018 , 118 , 142–231. 4. J. Serrano-Plana, C. Rumo, J.G. Rebelein, R.L. Peterson, M. Barnet, T.R. Ward, J. Am. Chem. Soc. 2020 , 142 , 10617– 10623.

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Multidentate halogen-bond based catalysis: a computational study Nika Melnyk 1 , Marianne Rica Garcia 1 and Dr. Cristina Trujillo 1,2 1 Trinity College Dublin, Ireland, 2 University of Manchester, UK Organocatalysis, the use of small organic molecules in order to facilitate transformations, remains one of the most challenging topics in contemporary organic chemistry. The activation of substrates and reactants through organocatalysis is often classified into covalent and non-covalent catalysis. In the latter category, hydrogen bonding (HB) is the most well-established interaction. In the last years, the research field of σ-hole interactions is gaining increasing attention in the field of organocatalysis. 1-4 The name “σ-hole interactions” that is frequently used to describe these noncovalent forces was initially proposed by Clark, Murray, and Politzer in 2007, 5 and was chosen to reflect the relative position in elongation of σ-bonds.Inspired by the nature of the customary hydrogen bonding, halogen bonding (XB) is suggested to be a worthy alternative due to novel features such as its robust directionality. 1-4 The polarizability of the sigma hole of the XB-donor atom and the electronic effect of the attached organic framework have been explored computationally. The halogen atom (I, Br or Cl) in a symmetrical bidentate organocatalyst was varied and the mechanistic insights as well as the different non-covalent interactions (NCI) established in the Michael addition reaction upon complexation have been investigated by means of density functional theory (DFT). References 1. H. Yang and M. W. Wong, Molecules , 2020, 25 , 1045. A. M. Phillips, M. H. Prechtl and A. J. Pombeiro, Catalysts , 2021, 11 , 569. 2. V. Oliveira, M. Cardoso and L. Forezi, Catalysts , 2018, 8 , 605. M. Breugst and J. J. Koenig, European Journal of Organic Chemistry, 2020, 34 , 5473–5487. 3. T. Clark, M. Hennemann, J. S. Murray and P. Politzer, Journal of Molecular Modeling , 2006, 13 , 291–296.

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Investigating new photoactive ferroelectrics using dynamic X-ray diffraction techniques Josh Morris and Lauren Hatcher Cardiff University, UK The generation of renewable, cheap energy via the realisation of solar energy capture (SEC) materials is key to mitigating some of the effects of our current worsening climate. We are developing a range of novel ferroelectric solar energy capture materials, whose function arises from thermally-induced spin-crossover (SCO), linkage photoisomerism (LI) 1 or charge-transfer-induced spin-transitions (CTIST). Structure:function relationships in SCO and LI materials is not well understood, with competing ideas having been put forth to explain experimental results. To further our understanding of these materials, we have synthesised SCO materials based on Fe(bis(pyrazol-1-yl)pyridine) complexes, LI materials based on modified sodium nitroprusside analogues, and CTIST materials based on functionalised Co-Fe Prussian Blue Analogues (PBAs). Single-crystal structures, PXRD patterns, and dielectric data in particular have been collected across this range of SEC materials under a range of stimuli to explore their potential for applications. 2 These materials are designed to undergo a phase-transitions as a result of their interaction with external stimuli, ideally generating ferroelectric phases by inducing polar organic cation alignment in LI- and CTIST-active frameworks, or causing a symmetry change in SCO complexes. In addition to continuing our study of electric field induced polar cation alignment in SNP analogues, we are conducting further SCXRD and computational experiments to determine how the constituent moieties of each materials imparts an effect on the observed phase-transition temperature and behaviour. References 1. Journal of the American Chemical Society 119 , 11, 2669-2678, (1997) 2. J. Appl. Cryst. 54 , 1349-1359, (2021

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Dicoordinate Au(I)–ethylene complexes as hydroamination catalysts Miquel Navarro, Macarena G. Alférez, Juan Miranda-Pizarro, Juan J. Moreno, Jesús Campos Universidad de Sevilla, Spain p-Complexes of gold are generally proposed as key intermediates in the functionalization of alkenes, alkynes, dienes or allenes in a wide range of catalytic processes. [1] Thus, the isolation of gold p-complexes holds an intrinsic interest associated with their catalytic relevance and has provided valuable insights during the last years. Cationic gold(I) p-complexes of substituted alkenes have been stabilized by monodentate and bidentate ligands. However, despite significant synthetic efforts, dicoordinate ethylene complexes remain unknown and only by using N- and P-based bidentate ligands the related tricoordinate gold(I) p-ethylene adducts. [2] The use of bulky phosphine ligands has allowed the stabilization, isolation and complete characterization of the first dicoordinate gold(I)–ethylene adducts. [3] The bonding situation of these species has been investigated by means of state-of-the-art Density Functional Theory (DFT) calculations. In addition, the lability of the gold- ethylene bond has also been interrogated. For instance, the use of these sterically congested ligands have proved crucial to stabilize the gold(I)–ethylene bond and prevent decomposition, boosting up their catalytic performance in the highly underexplored hydroamination of ethylene. [4] As a result, the precatalysts bearing the most sterically demanding phosphines showed excellent results reaching full conversion to the hydroaminated products under notably mild conditions, highlighting the high catalytic potential of very sterically crowded catalysts. References 1. G. Dyker. Angew. Chem. Int. Ed. 2000 , 39 , 4237; b) A. S. K. Hashmi, Gold Bull. 2004 , 37 , 51. 2. M. Navarro, D. Bourissou. Adv. Organomet. Chem. 2021 , 76 , 101. 3. J. Keller, C. Schlierf, C. Nolte, P. Mayer, B. F. Straub. Synthesis 2006 , 2 , 354; b) M. Navarro, J. Miranda-Pizarro, J. J. Moreno, C. Navarro-Gilabert, I. Fernández, J. Campos. Chem. Commun. 2021 , 57 , 9280. 4. Z. Zhang, S. D. Lee, R. A. Widenhoefer. J. Am. Chem. Soc. 2009 , 131 , 5372; b) M. Navarro, M. G. Alférez, M. de Sousa, J. Miranda-Pizarro, J. Campos. ACS Catal. 2022 , 12 , 4227.

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Harnessing non-covalent interactions for peptide encapsulation within metal-organic materials Imogen Riddell, Xiangyu Wang, Tongtong Zhang, Jonathan Robson, Maria Giovanna Lizio, Daniel Bell, Jack Wright University of Manchester, UK Metal-organic containers have shown utility in diverse applications from gas storage to catalysis, 1 however their application within biological contexts remains in its infancy. We are interested in exploiting the unique internal environments of porous metal-organic materials to better understand the effects of protein constriction. Enzymes exhibit high catalytic efficiency and specificity making them desirable candidates for application in biotechnology settings. However, the inherent fragility of these structures arising from their tendency to become denatured following exposure to moderate temperature or pH changes, and organic solvents remains a major drawback. Materials capable of reinforcing the three-dimensional structure of proteins and preventing loss of catalytic activity (and possibly even enhancing it) 2 are highly desirable. Factors governing the spontaneous biomimetic crystallization 3 of MOFs around proteins will be discussed as well as techniques for characterisation of these hybrid materials. Synthesis and characterisation of metal-organic cages displaying sequence selective binding of short peptides directed by non-covalent interactions will also be presented. Evaluation of peptide binding within well-defined void pockets, which can be tailored, provides a route to understand the effects crowded cellular environments 4 have on peptide folding. Such synthetic complexes may ultimately guide the design of capsules capable of directing refolding of un/misfolded peptide sequences. 5 References 1. N.Ahmad,H. A. Younus,A. H. Chughtai, F. Verpoort, Chem. Soc. Rev . , 2015, 44 , 9. 2. K. Liang, R. Ricco, C. M. D., M. J. Styles, S. Bell, N. Kirby, S. Mudie, D. Haylock, A. J. Hill, C. J. Doonan, P. Falcaro, Nat. Commun ., 2015, 6 , 7240. 3. J. Liang, M. Y. B. Zulkifli, J. Yong, Z. Du, Z. Ao, A. Rawal, J. A. Scott, J. R. Harmer, J. Wang, K. Liang, J. Am. Chem. Soc, 2022, 144 , 17865. 4. A. P. Minton, J. Biol.Chem ., 2001, 276 , 10577. T. Nishimura, K. Akiyoshi, Bioconjugate Chem. 2020, 31 , 1259.

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