A number of complexes in the series (Cu LL'),, where L = [(CH,),C-CO-CH-COC(
CH,),]-I and L'= 3-(Me) C6H,0-, 2,6-(Di-Me)C6H30-, 4-(OH)C6H?O-, 3- (F)
C6H,0-, 4-(Br)C6H40-a, nd 3,s-(Dl-Me)C6H30h- ave been prepared and theu magnetic
and optical properties determined. In chloroform, the complexes exhibit two bands
in the visible and near UV regions. All complexes show room temperature magnetic
moment order of 1.0 B.M. per copper atom. The X-band ESR spectrum of solution
samples at room temperature shows typical hm=l transition. An electron release or
withdrawing group on bridging ligand causes a great change in spin-spin interaction
and is observable at Am =2 transition at half-field, which is the characteristic of
dimeric unit