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

Abstract

AbstractTriorganotin, 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 in 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 a two‐dimensional polymer of puckered 22‐membered [(Me3Sn)2ADC] and 26‐membered [(Me3Sn)2TER] 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.