An electron paramagnetic resonance (EPR) study on exchange coupling inthe bimetallic chain compound copper(II) bisethylenediamine manganese(II)tetrachloride (CEMC) and interpretation of EPR linewidth data of two otherCu-Mn bimetallic chain compounds

Abstract

Investigations of the linewidth, lineshape and intensity of the X-band EPRline observed in several crystallographic planes of the bimetallic chaincompound copper(II) bis ethylenediamine manganese(II) tetrachloride (CEMC) arecarried out at room and liquid nitrogen temperatures. The observed angularanisotropy of the linewidth has been satisfactory explained on the basis ofthe anisotropic exchange model and of the effective spin S = 2 formalism. Itis inferred that the CEMC crystal is well described as constituted of FM coupledCu-Mn dimeric chains oriented parallel to the c-axis of the monocliniccrystal. Within each Cu-Mn dimer exchange coupling is, however, of AFM type.The above model has also been successfully applied to interpret anisotropiclinewidth data obtained in two other Cu-Mn bimetallic chain monocliniccompounds, namely, MnCu(pba)(H2O)3.2H2O and MnCu(pbaOH)(H2O)3.