| Abstract
| - A series of 7 cerium double-decker complexes with various tetrapyrrole ligands includingporphyrinates, phthalocyaninates, and 2,3-naphthalocyaninates have been prepared by previously describedmethodologies and characterized with elemental analysis and a range of spectroscopic methods. Themolecular structures of two heteroleptic [(na)phthalocyaninato](porphyrinato) complexes have also beendetermined by X-ray diffraction analysis which exhibit a slightly distorted square antiprismatic geometrywith two domed ligands. Having a range of tetrapyrrole ligands with very different electronic properties,these compounds have been systematically investigated for the effects of ligands on the valence of thecerium center. On the basis of the spectroscopic (UV−vis, near-IR, IR, and Raman), electrochemical, andstructural data of these compounds and compared with those of the other rare earth(III) counterparts reportedearlier, it has been found that the cerium center adopts an intermediate valence in these complexes. Itassumes a virtually trivalent state in cerium bis(tetra-tert-butylnaphthalocyaninate) as a result of the twoelectron rich naphthalocyaninato ligands, which facilitate the delocalization of electron from the ligands tothe metal center. For the rest of the cerium double-deckers, the cerium center is predominantly tetravalent.The valences (3.59−3.68) have been quantified according to their LIII-edge X-ray absorption near-edgestructure (XANES) profiles.
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