Structure and spectroscopic properties of phthalocyaninato zinc(II) complexes fused with different number of 15-crown-5 moieties

A series of structurally closely related phthalocyaninato zinc(II) complexes fused with different number and/or disposition of 15-crown-5 groups at the peripheral positions Zn(Pc′) (1–6) [Pc′ = Pc, Pc(15C5), Pc(opp-15C5)2, Pc(adj-15C5)2, Pc(15C5)3, Pc(15C5)4; Pc = unsubstituted phthalocyaninate; Pc(15C5) = 2,3-(15-crown-5)phthalocyaninate; Pc(opp-15C5)2 = 2,3,16,17-bis(15-crown-5)phthalocyaninate; Pc(adj-15C5)2 = 2,3,9,10-bis(15-crown-5)phthalocyaninate; Pc(15C5)3 = 2,3,9,10,16,17-tris(15-crown-5)phthalocyaninate; Pc(15C5)4 = 2,3,9,10,16,17,24,25-tetrakis(15-crown-5)phthalocyaninate] have been designed, prepared, and spectroscopically characterized. The effect of number and dispositions of 15-crown-5 moieties on their electronic and vibrational spectroscopic properties was understood by systematic investigation over the electronic absorption, infra-red (IR), and Raman spectra of this series of phthalocyaninato zinc complexes. In addition, density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were carried out to comparatively describe the molecular structures, atomic charges, electronic absorption spectra, infrared (IR), and Raman spectra of 1–6, revealing the nature of the main transitions in electronic absorption spectra and identifying the vibration modes in the IR and Raman spectra of the series of six complexes with the assistance of animated pictures produced on the basis of the normal coordinates.