Cadmium(II) complexes containing a discrete tetrakis-(carboxylato)-bridged dimetal core: isomorphous dinitratotetrakis(µ-triphenylphosphoniopropionate)dicadmium(II) dinitrate and diperchlorate, and dichlorotetrakis(µ-triphenylphosphoniopropionate)dicadmium(II) diperchlorate

Abstract

Three cadmium complexes that contain the tertiary phosphine betaine ligand triphenylphosphoniopropionate have been synthesized and structurally characterized by single-crystal X-ray analysis. The complex [{Cd[Ph₃P(CH₂)₂CO₂]₂][NO₃]}₂][NO₃]₂1 belongs to the triclinic space group P1 with a= 9.152(3), b= 12.833(4), c= 19.278(12)Å, α= 102.25(5), β= 97.20(4), γ= 108.19(5)° and Z= 1; [{Cd[Ph₃P(CH₂)₂CO₂]₂(NO₃)}₂][ClO₄]₂2 is isomorphous with 1 with a= 9.136(6), b= 12.891(2), c= 20.138(5)Å, α= 104.51(1), β= 97.54(4), γ= 107.86(3)°; [{Cd[Ph₃P(CH₂)₂CO₂]₂CI}₂][CIO₄]₂3 is monoclinic, space group C2/m with a= 9.315(5), b= 37.275(15), c= 13.255(6)Å, β= 112.45(4)° and Z= 2. All three complexes possess a centrosymmetric tetrakis(µ-carboxylato-O,O′) dimetal core, the apical sites being occupied by chelating nitrato ions in 1 and 2 and by chloro groups in 3. In complexes 1 and 2, the metal atoms are symmetrically bridged by the carboxylato groups, but in 3 the carboxylato group is distorted significantly. The intramolecular Cd ⋯ Cd distances are 3.278(2), 3.278(2) and 3.361(2), respectively.