Preparation and structure of triorganotin, triorganolead and tetraphenylantimony derivatives of acetylenedicarboxylic acid, terephthalic acid and dithioterephtalic acid

Article abstract of DOI:10.1002/recl.19881070333

Triorganotin, triorganolead and tetraphenylantimony derivatives of acetylenedicarboxylic acid (H2ADC), terephthalic acid (H2TER) and dithioterephthalic acid (H2DTT) (R3M)2X (M= Sn, Pb; R= Me, Ph; X= ADC, TER, DTT) and (Ph4SB)2X (X= ADC, TER) were prepared by neutralization of R3MOH or PH4SbOH with the appropriate acid (X= ADC, DTT) or by reaction of R3MCl or Ph4SbCl with K2TER.The crystal structures of (Me3Sn)2ADC and (Me3Sn)2TER were determined by X-ray diffraction.The Sn atoms are slightly distorted trigonal-bipyramidal environments, with C(Me) in the equatorial plane and O(carboxyl) in apical positions.The carboxylate groups are bridging, leading to the formation of two-dimensional polymer of puckered 22-membered <(Me3Sn)2ADC> and 26-memberd rings.From vibrational spectra, analogous structures are inferred for solid (Ph3Sn)2ADC, (R3Pb)2ADC (R= Me, Ph), and (Me3Pb)2TER, but structures with unidentate -COO and -COS groups and tetracoordinated Sn or Pb and pentacoordinated Sb are proposed for the other compounds.The DTT ligands are linked by S bonds to M.According to IR and 1H NMR studies the polymeric species dissociate on dissolution so that generally species with unidentate carboxylate groups are present.Sn and Pb in (R3M)2X (X= ADC, TER) are apparently tetracoordinated in CHCl3, but pentacoordinated in DMSO by addition of a solvent molecule.