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Coordination Chemistry at the SRS Sandy Blake, School of Chemistry, University of Nottingham.

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Presentation on theme: "Coordination Chemistry at the SRS Sandy Blake, School of Chemistry, University of Nottingham."— Presentation transcript:

1 Coordination Chemistry at the SRS Sandy Blake, School of Chemistry, University of Nottingham

2 Outline of talk accessing the SRS via the National Crystallography Service at Southampton an Approved Programme at the SRS a direct access application

3 EPSRC National Service project allocations Dr Polly Arnold: Anionic N-heterocyclic carbene complexes for early metals Professor Neil Champness: Porous co-ordination networks Professor Dave Garner: Complexes of non-innocent ligands Dr Peter Hubberstey: Developments in transition metal structural chemistry Dr Jason Love: Reactions of small molecules in well-defined, bimetallic molecular clefts Professor Martin Schröder: Solvent extraction of metals salts by ditopic ligands; metal- organic frameworks; metal-thiolate interactions in biology 92

4 EPSRC National Service - our use of the SRS about half the samples we submit go to the SRS success rate varies by project from 33% to 80% 60 datasets collected over the last four years most have solved and refined satisfactorily many successful structures have been published a large number are in recently submitted papers

5 EPSRC National Service “Group (I) cation templated formation of luminescent mono- and bis-substituted thionaphthol heterobimetallic complexes of Pr, Nd, Eu and Tb” L.S. Natrajan, A.J. Blake, C. Wilson, J.A. Weinstein, P.L. Arnold, Dalton Trans The structural results played a key role in rationalising the luminescent behaviour of the complexes. The disposition of the naphthyl groups in the bis- L SN complex is such that a scissoring motion could cause them to overlap and provide the conditions for excimer formation.

6 EPSRC National Service “Structural influence of cis and trans coordination modes of multi-modal ligands upon coordination polymer dimensionality” N.S. Oxtoby, A.J. Blake, N.R. Champness, C. Wilson, Dalton Trans. 2003, Controlling the arrangement of the ligand donor atoms allows structural discrimination between one- and two- dimensions in two coordination frameworks, {[AgNO 3 ] 2 L} ∞, formed between AgNO 3 and hexadentate multi- modal ligands. One framework contains one-dimensional tapes composed of [2+2] metallacycles, while the other adopts a grid structure with a 4 4 topology.

7 EPSRC National Service “Structural characterisation of selenium and selenium-diiodine analogues of the antithyroid drug 6-n-propyl-2-thiouracil and its alkyl derivatives” C.D. Antoniadis, A.J. Blake, S.K. Hadjikakou, N. Hadjiliadis, P. Hubberstey, M. Schröder, C. Wilson, Acta Cryst. 2006, B62, in press. The structures of selenium analogues of the anti-thyroid drug 6-n-propyl-2-thiouracil, the charge-transfer complex 6-n-propyl-2- selenouracil·I 2, two diselenides and the deselenation product 6-n-propyl-2-uracil all show extended architectures. These are based on hydrogen bonding and, in the case of 6-n-propyl-2-selenouracil·I 2, Se···I interactions. Crystals tended to diffract weakly, so several of the structures are derived from SRS data.

8 An Approved Programme at the SRS “Coordination polymers for the hydrogen economy and for surface supramolecular assembly” four days beam time per six months awarded 2004 based on a number of EPSRC and other grants programme runs until late 2007 each six monthly renewal requires short application with progress and plans beam time reports

9 Approved Programme team of four people four one-day visits per allocation period together for training and first eight hours then two people rest other two work until midnight then we swap for the night shift

10 Approved Programme On the team Rob HillFrédéric Thébault Xiang LinJunhua Jia Colleen WilliamsDave Ring (Hareg Tadesse)

11 Approved Programme Overview of the last 18 months: 9 useful visits, 125 samples, 66 datasets most completed satisfactorily still working on several two abandoned Typical samples: i. solvothermally generated coordination polymers ii. polymers (i) with solvent removed by heating iii. replacement solvent added to (ii)

12 Approved Programme Samples are extremely challenging: small sizepoor crystallinity high solvent content twinningdisorder pseudosymmetry Some samples contain > 50% v/v solvent problems in handling    refinement

13 Approved Programme [Er(L)(NO 3 ) 33CH 2 Cl 2 In this example the solvent occupies 51% of the cell volume. It was modelled using SQUEEZE. (L = C 39 H 27 N 3 O 3 )

14 Approved Programme “Solid-state conversion to robust pores in Ln(III)-pyridine-3,5-dicarboxylate frameworks via loss of co-ordinated solvent: structure and gas storage” J. Jia, X. Lin, A.J. Blake, N.R. Champness, P. Hubberstey, L. Shao, G. Walker, C. Wilson & M. Schröder, Angew. Chem. 2006, submitted. The orthorhombic unit cell (left) possesses pseudo-hexagonal symmetry but upon desolvation it becomes truly hexagonal (right). The transformation also involves a reorganisation of the coordination sphere around the metal.  –DMF

15 A Direct Access Application “High pressure coordination chemistry of a palladium thioether complex: pressure versus electrons” discussed at Loughborough bid for three days beam time used in late November 2005 axial Pd … S1 distance vs P first HP study on Station 16.2 up to about 80 kbar using a diamond anvil cell structures determined at nine pressures

16 A Direct Access Application D.R. Allan, A.J. Blake, D. Huang & M. Schröder, to be submitted Highlights polymer formed distorted octahedral Pd new ligand conformation striking colour change For details see our poster CP63

17 Acknowledgements Claire Wilson EPSRC National Service Bill Clegg John Warren Tim Prior Dave Allan


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