Presence of Jahn-Teller distortions in a novel six-coordinate Ag(II) complex: temperature dependent EPR, optical and magnetic susceptibility measurements

Single-crystal variable temperature EPR, optical and polycrystalline magnetic susceptibility studies have been made on a novel six-coordinate Ag(II) complex. Temperature dependent EPR studies on pure single crystals of this compound reveal that dynamic Jahn-Teller distortion operates above 230K, between 230K and 120K static Jahn-Teller distortion sets in and below 110K there is evidence of exchange interaction. Crystal g values were obtained by least-squares fitting with the data obtained from the orientation dependent EPR spectra of the undiluted single crystal of this complex at 300K and 77K. From an optical study the JahnTeller stabilization energy is found to be 2250cm-1. Comparison of Absmax values for other silver(II) compounds enables us to conclude that the formal geometry of this complex is a tetragonally distorted octahedral. Infrared spectra of this complex were also recorded over a wide range of temperature. Magnetic susceptibility measurements over a wide range of temperature on the powder sample of this compound reveal that the complex is antiferromagnetically coupled in the temperature range 5-40K with 2 J = 0.906cm-1, and above 40K it is ferromagnetically coupled with 2 J = +7.4cm-1. The effective magnetic moment (mueff) of this complex has been compared with that of a series of other silver (II) complexes available in the literature. Finally, the spectral and magnetic data of this complex have been compared with those of a corresponding isostructural and isomorphous copper(II) complex.