title: Spectroscopic and structural study of metal-metal bonded metalloporphyrinic derivatives: the case of rhodium-indium.
abstract: The synthesis and spectroscopic characterization of heterometallic porphyrinate derivatives containing rhodium-indium metal-metal bonds are reported. The investigated compounds are represented by the formula [(Porph)RhIn(Porph')], where Porph and Porph' are OEP, TPP, beta-Cl(4)TPP, beta-Cl(8)TPP, or TPyP. UV-Visible spectroscopy of the title complexes confirms the presence of a strong pi-pi interaction between the macrocycles in each derivative and denotes the effect of the nontransition metal in their optical features. For comparison purposes, a new bimetallic complex with a rhodium-thallium metal-metal bond is also presented. According to (1)H and (13)C NMR data, we were able to distinguish two major NMR regions: the endo- between the metal-metal bonded macrocycles and the exo-, which are characteristic features of porphyrinic complexes at very close proximity. X-ray absorption spectroscopy (XAS) structural characterization of Rh-In bond was performed on the [(OEP)RhIn(OEP)] complex, in the fluorescence mode, and we essentially focused on the metal-metal distance determination. Finally, the distance of 2.543(3) A was deduced from the X-ray structure of a new [(TPP)RhIn(TPyP)] derivative.
authors.affiliation: Department of Chemistry, School of Sciences, University of Crete, P O Box 1470, 71409 Heraklion Crete, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Daphnomili
authors.forename: C
authors.initials: C
authors.lastname: Raptopoulou
authors.forename: A
authors.initials: A
authors.lastname: Terzis
authors.forename: J-H
authors.initials: JH
authors.lastname: Agondanou
authors.forename: S
authors.initials: S
authors.lastname: Bénazeth
authors.forename: A G
authors.initials: AG
authors.lastname: Coutsolelos