Syntheses and structural comparisons of two copper(II) complexes with the same formula having d-(+)- and d,l-1,2,2-trimethylcyclopentane-1,3-diamine ligands

Two five-coordinate copper(II) complexes, formulated as [Cu(La)2Cl]BF4 (1) and [Cu(Lb)2Cl]BF4 (2) having d-(+)-1,2,2-trimethylcyclopentane-1,3-diamine (La) and d,l-1,2,2-trimethylcyclopentane-1,3-diamine (Lb) ligands, have been synthesized and characterized. X-ray diffraction studies of 1 and 2 demonstrate that they crystallize in the different space groups (P212121 for 1 and Pnma for 2), although they have identical unit cell volumes, due to the use of enantiomeric and racemic diamine ligands. One dimensional (1D) hydrogen-bond-sustained dimeric zigzag chains are formed by means of eight-membered N2H2CuBF2 as well as 10-membered N2H4ClBF2 hydrogen-bonded cycles. Thermal analyses for 1 and 2 are also described herein.