Evaluation of Ground and Excited State Dipole Moments of 2(3)tetra(tertbutylphenoxy)phthalocyaninato Zinc(II) from Solvatochromic Data

This article presents a semiempirical determination of ground state dipole moment (mg) and excited state dipole moment (me) of 2(3)tetra(tertbutylphenoxy)phthalocyaninato zinc(II) (ZnTBPc) using the solvatochromic shift method, which is based on the Onsager’s reaction field theory. A combined application of the Bakshiev’s equation and the KawskiChammaViallet’s equation was used to determine the ratio me/mg while the use of the molecularmicroscopic solvent polarity parameter yielded the term Dm (me mg). The dipole moment of ZnTBPc in its excited singlet state (me=4.46D) is more than twice as much as that in its ground state (mg=2.14D).These values suggest that the higher charge separation is greater in the excited state of ZnTBPc than in its ground state.