Infra-red and Raman spectroscopic study of tetra-substituted bis(phthalocyaninato) rare earth complexes peripherally substituted with tert-butyl derivatives.
The infra-red spectroscopic data for a series of 13 homoleptic substituted bis(phthalocyaninato) rare earth complexes with tervalent rare earths M(III)(TBPc)(2) [M=Y, Pr, ..., Lu except La, Ce and Pm; TBPc=dianion of 3(4),12(13),21(22),30(31)-tetra(tert-butyl)-phthalocyanine] have been collected with resolution of 2 cm(-1). Raman spectroscopic properties in the range of 500-1,800 cm(-1) for these double-deckers M(III)(TBPc)(2) have been collected using laser excitation sources emitting at 632.8 nm. Both the IR and Raman spectra for M(III)(TBPc)(2) are more complicated than those of homoleptic bis(phthalocyaninato) rare earth analogues due to the decreased molecular symmetry of these double-decker compounds. For this series, the IR typical marker band of (TBPc)(-) appears as an intense absorption at 1,314-1,319 cm(-1), attributed to the pyrrole stretching. Under excitation at 632.8 nm that is in close resonance with the main Q absorption band of phthalocyanine ligand, typical Raman marker band of the monoanion radical (TBPc)(-) was observed at 1,515-1,530 cm(-1) resulting from aza CN stretching. Both techniques reveal that the frequencies of pyrrole stretching, isoindole breathing and aza stretchings depend on the rare earth ionic size, shifting to higher energy along with the lanthanide contraction due to the increased ring-ring interaction across the series.
Lu
Fanli
F
Department of Chemistry, School of Sciences, Tianjin University, Tianjin 300072, PR China. fanlilu@tju.edu.cn
Yang
Qiuhua
Q
Cui
Jianzhong
J
Yan
Xiuru
X
D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D008674:Metals, Rare Earth / Q000737:chemistry*; D008968:Molecular Conformation; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman
D007211:Indoles; D054833:Isoindoles; D008674:Metals, Rare Earth; C013647:phthalocyanine