A series of heteroleptic chelate copper(II) complexes of the type [Cu(L)(acac)]X where acac = acetylacetonate; L = N,N-1,6-bis(2-uorophenyl)-2,5-diazahexane; X = CIO4−, BPh4 −, PF6−, and BF4− have been prepared and characterized by elemental analyses,IR and UV-Vis spectroscopies, and molar conductance measurements. e prepared complexes are fairly soluble in a large numberof organic solvents and show positive solvatochromism. Among the complexes [Cu(L)(acac)]ClO4, it is demonstrated the most solvatochromism. A multiparametric equation has been utilized to explain the solvent effect on the d-d transition of the complexes using SPSS/PC soware. To explore the mechanism of interaction between solvent molecules and the complexes, different solvent parameters such as DN, AN, 𝛼, 𝐸𝑇(30), 𝜋∗, and 𝛽 using stepwise multiple linear regression (SMLR) method were employed. e results demonstrated that the donor power of the solvent plays the most important role in the solvatochromism of the compounds.
