Monomer-polymer forms of solid, unsolvated, 5-coordinate halodimethyl(2-diphenylphosphinylethyl)stannanes, XMe2SnCH2CH2P(O)Ph-2 (X = Cl, Br or I). Effects of different recrystallisation media

W T A Harrison, R A Howie, C M Munro, J L Wardell

Research output: Contribution to journalArticle

Abstract

As determined by X-ray crystallography, unsolvated XMe2SnCH2CH2P(O)Ph-2 (X = Cl, Br or I) crystallises in two forms: linear chain polymers. obtained by recrystallisation from EtOH or McOH, and chelated monomers from non-hydroxylic solvents, such as chlorocarbons and acetone. The linear chains are formed by intermolecular Sn-O interactions [at 301 K, 2.339(2) (X = Cl): 2.309(3) (X = Br): 2.282(3) Angstrom (X = I)]: the resulting 5-coordinate tin centres have trigonal bipyramidal geometries, with the halide and the oxygen atoms in axial sites. The chelated forms, with intramolecular Sn-O interactions [also at 301 K: 2.3989(15) (X = Cl): 2.381(2) (X = Br): 2.386(2) Angstrom (X = I)], also contain 5-coordinate tin centres, with trigonal bipyramidal geometries and with the halide and the oxygen atoms in axial sites. As shown by X-ray powder patterns, cooling the melt of polymer-(2: X = I) gave chelate-(2: X = I). The isothiocyanato analogue, (SCN)Me2SnCH2CH2P(O,)Ph-2, crystallises in the monomeric chelated form from all solvents attempted for recrystallisation [Sn-O = 2.3865(19) and 2.3920(19) Angstrom], in two independent molecules.

Original languageEnglish
Pages (from-to)2593-2600
Number of pages8
JournalJournal of the Chemical Society, Dalton Transactions
Publication statusPublished - 2001

Keywords

  • STATE COORDINATION BEHAVIOR
  • MOLECULAR-STRUCTURE
  • MULTINUCLEAR NMR
  • RAY-DIFFRACTION
  • TRIPHENYLPHOSPHINE OXIDE
  • DERIVATIVES
  • CRYSTAL
  • STEREOISOMERIZATION
  • N=3-5

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