Infra-red spectroscopic characteristics of naphthalocyanine in bis(naphthalocyaninato) rare earth complexes peripherally substituted with thiophenyl derivatives

摘要

The infra-red (IR) spectroscopic data for a series of eleven rare earth double-deckers M-III[Nc(SPh)(8)](2) (M = Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er) have been collected and systematically investigated. For M-III[Nc(SPh)(8)](2), typical IR marker bands for the naphthalocyanine anion radical [Nc(SPh)(8)](.-) were observed at 1317-1325 cm(-1) as the most intense absorption bands, which can be attributed to the pyrrole stretching. As for Ce[Nc(SPh)(8)](2), the typical IR marker band was also observed at 1317 cm-1, which shows that the cerium complex exists as the form of Ce-III[Nc(SPh)(8)](2)(-)[Nc(SPh)(8)](.-). In addition, both the Q-bands of electronic absorption spectra and the typical IR absorption bands of naphthalocyanine radical anion [Nc(SPh)(8)](.-) move to the high energy as the decrease of rare earth metal ionic radius. These facts suggest that the pi-pi electron interaction in these double-deckers becomes stronger along with the lanthanide contraction. (C) 2014 Elsevier B.V. All rights reserved.