The Halogen to Sulfur Dioxide Bond. Structure of Iodo(sulfur dioxide)methylbis(triphenylphosphine)platinum, Pt(CH3)(PPh3)2I-SO2

Michael R. Snow, James A. Ibers*

*Corresponding author for this work

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The adduct Pt(CH3)(PPh3)2I-SO2 crystallizes from a benzene solution of the metal complex saturated with sulfur dioxide. Its crystal structure has been determined from 3143 independent reflections collected by counter methods. The yellow crystals are triclinic, space group PI, with a reduced cell of a = 11. 853 (6) A, b = 16. 610 (9) A, c = 9. 738 (5) A, a = 98. 12 (2)°, β= 108. 17 (1)°, y = 69. 90 (2)°, and Z = 2. The absorption corrected data gave a conventional R factor of 0. 027 on full-matrix least-squares refinement. The Pt(CH3)(PPh3)2I portion of the molecule has triphenylphosphine groups trans to one another. The iodine atom forms a weak bond to sulfur (3. 391 (3) A) which is shorter by 0. 4 A than the van der Waals radii sum (3. 80 A), though much longer than expected for a single covalent bond (2. 37 A). The angle O-S-O is 116. 1 (5)° and the I-S vector makes an angle of 21. 3 (5)° with the normal to the SO2 plane. By comparisons of infrared spectra and molecular geometry this adduct is shown to be similar to adducts of sulfur dioxide with metal complexes and with amines. It is also a good model for sulfur dioxide solvates of halide salts, none of which has yet been structurally characterized. The compound O2S-Ir(CO)(PPh3)2I-SO2 has been prepared in which there are SO2 attachments to both iridium and iodine.

Original languageEnglish (US)
Pages (from-to)224-229
Number of pages6
JournalInorganic chemistry
Issue number1
Publication statusPublished - Jan 1 1973


ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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