Recently, there have been many reports on the late transition metal complexes as catalysts for olefin homo- and copolymerization [1-3]. Bao et al. [4] have been investigated on a series of copper (II) complexes of β-ketoamine ligands for polymerization of olefins. According to Gurr\\\\\\\\\\\\\\\'s study [5], the unit cells of bis (4-aminopent-3-en-2-onato) copper (II), Cu(APO)2, and bis (3-amino-1-phenyl-2-buten-1-onato) copper (II), Cu(APBO)2, are orthorhombic and monoclinic, respectively. In this work, we have given the modified synthesis, X-ray crystallography information, and calculated formation constants of Cu(APBO)2 by means of density functional theory (DFT) studies and have compared with those observed experimentally. The results also compared with Cu(APO)2 [6]. The results show that the single crystal of Cu(APBO)2 is more regular than Cu(APO)2 (Figs. 1 and 2) and crystallographic and DFT calculation data of Cu(APBO)2 are closer to each other than those of Cu(APO)2. UV-vis. spectrum of Cu(APBO)2 indicates λmax at 580 nm related to ΔEelect = 206 kJ mole-1; however, these values for Cu(APO)2 are 567 nm and 211 kJ mole-1, respectively. In DFT calculations, ΔEelect was considered as the difference between HOMO and LUMO orbitals and obtained 400 and 459 kJ mole-1 for Cu(APBO)2 and Cu(APO)2, respectively. π-delocalization of electrons in Cu(APBO)2 is responsible for the less difference between HOMO and LUMO energy levels. According to the theoretical calculations, the formation constants of Cu(APBO)2 and Cu(APO)2 are 6.93x10^17 and 5.57x10^12, respectively. These are in agreement with the geometries and the difference between HOMO and LUMO calculated energies.

Keywords