SOLID-STATE MOSSBAUER, EPR, MAGNETIC-PROPERTIES AND THERMALLY-INDUCEDSTEREOCHEMICAL STUDIES ON DOUBLE COMPLEX SALTS OF CYCLIC DIAMINE CONTAINING CATIONIC COPPER(II) COMPLEXES AND A HEXACYANOFERRATE(III) ANION

Double complex salts containing cationic Cu-II having cyclic ligand pi perazine (pipz), N-methylpiperazine (mpipz) and N,N'-dimethylpiperazin e (dmpipz) and hexacyanoferrate(III) ion have been synthesized and cha racterized by elemental analyses, i.r. and electronic spectra, and mag netic moment measurements. Mossbauer spectra at room temperature and a t 80 K, were recorded in order to evaluate the metal-metal charge tran sfer and the impact of the cyclic ligand present in cationic moiety of the double complex salt upon the Mossbauer spectra of the hexacyanofe rrate(III) ion. Evidence for metal-metal charge transfer is supported by electronic spectra and magnetic susceptibilities. Variable temperat ure e.p.r. spectra were recorded in order to determine the distortion of crystal system. Thermally induced stereochemical studies have been carried out with the help of i.r. spectral data. Kinetics of thermoche mical reactions have also been studied. Activation energies (E(a)) an d inception temperatures for the thermochemical reactions show the ord er of stability of the double complex salts follows the trend: dmpipz > mpipz > pipz, which indicates that the +I effect is more pronounced than steric effect.