title: High-pressure studies of palladium and platinum thioether macrocyclic dihalide complexes.
abstract: The mononuclear macrocyclic Pd(II) complex cis-[PdCl2([9]aneS3)] ([9]aneS3 = 1,4,7-trithiacyclo-nonane) converts at 44 kbar into an intensely coloured chain polymer exhibiting distorted octahedral coordination at the metal centre and an unprecedented [1233] conformation for the thioether ligand. The evolution of an intramolecular axial sulfur-metal interaction and an intermolecular equatorial sulfur-metal interaction is central to these changes. High-pressure crystallographic experiments have also been undertaken on the related complexes [PtCl2([9]aneS3)], [PdBr2([9]aneS3)], [PtBr2([9]aneS3)], [PdI2([9]aneS3)] and [PtI2([9]aneS3)] in order to establish the effects of changing the halide ligands and the metal centre on the behaviour of these complexes under pressure. While all complexes undergo contraction of the various interaction distances with increasing pressure, only [PdCl2([9]aneS3)] undergoes a phase change. Pressure-induced I...I interactions were observed for [PdI2([9]aneS3)] and [PtI2([9]aneS3)] at 19 kbar, but the corresponding Br...Br interactions in [PdBr2([9]aneS3)] and [PtBr2([9]aneS3)] only become significant at much higher pressure (58 kbar). Accompanying density functional theory (DFT) calculations have yielded interaction energies and bond orders for the sulfur-metal interactions.
authors.affiliation: Beamline I19, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, England.
authors.forename: David R
authors.initials: DR
authors.lastname: Allan
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bailey
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Nigel
authors.initials: N
authors.lastname: Bird
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Blake
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Neil R
authors.initials: NR
authors.lastname: Champness
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Deguang
authors.initials: D
authors.lastname: Huang
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Conal P
authors.initials: CP
authors.lastname: Keane
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Jonathan
authors.initials: J
authors.lastname: McMaster
authors.affiliation: Department of Chemistry, University of Hull, Hull HU6 7RX, England.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Prior
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Jeremiah P
authors.initials: JP
authors.lastname: Tidey
authors.affiliation: School of Chemistry, The University of Nottingham, University Park, Nottingham, Nottinghamshire NG7 2RD, England.
authors.forename: Martin
authors.initials: M
authors.lastname: Schröder
keywords: conformation; coordination complexes; high pressure; intermolecular contacts; macrocycle; polymerization