Macromolecular arrays containing Zn-diethynylporphyrin coordinated to platinum tethers were studied using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the N K-edge. Porphin (Pf), 2,8,12,18-tetraethyl-5,15-diethynyl-3,7,13,17-tetramethylporphyrin (PfNH) and 2,8,12,18-tetraethyl-5,15-diethynyl-3,7,13,17-tetramethylporphyrinatozinc(II) (Zn-Pf2), have been taken as experimental models. The resonances assignment is supported by static-exchange (STEX) calculations for the porphin (Pf) and Zn-porphin (Zn-Pf1) molecules. By calculation, four pi* resonances occur for porphin (Pf) and two for Zn-Pf1. Experimentally we detect four resonances for porphin and PfNH, and two for the Zn-complexed ones. They can be assigned to core excitations to a couple of energy split pi* orbitals for each not equivalent N atom. Our calculations justify the observed low pi* intensity as due to an extended delocalization of the pi* orbitals. The NEXAFS investigations on platinum complex/Zn-porphyrinato assembled macrosystems (i.e. Pt-ZnPf1, Pt-ZnPf2 and Pt-ZnPf3) show the influence of the Pt tethers bound to the porphyrin through the ethynyl moiety on the electronic structure of the tetrapyrrolic cycle. (C) 2003 Elsevier B.V. All rights reserved.
Electronic structure of platinum complex/Zn-porphyrinato assembled macrosystems, related precursors and model molecules, as probed by X-ray absorption spectroscopy (NEXAFS): theory and experiment / G., Polzonetti; V., Carravetta; G., Iucci; A., Ferri; G., Paolucci; A., Goldoni; P., Parent; C., Laffon; Russo, Maria Vittoria. - In: CHEMICAL PHYSICS. - ISSN 0301-0104. - 296:1(2004), pp. 87-100. [10.1016/j.chemphys.2003.09.036]
Electronic structure of platinum complex/Zn-porphyrinato assembled macrosystems, related precursors and model molecules, as probed by X-ray absorption spectroscopy (NEXAFS): theory and experiment
RUSSO, Maria Vittoria
2004
Abstract
Macromolecular arrays containing Zn-diethynylporphyrin coordinated to platinum tethers were studied using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the N K-edge. Porphin (Pf), 2,8,12,18-tetraethyl-5,15-diethynyl-3,7,13,17-tetramethylporphyrin (PfNH) and 2,8,12,18-tetraethyl-5,15-diethynyl-3,7,13,17-tetramethylporphyrinatozinc(II) (Zn-Pf2), have been taken as experimental models. The resonances assignment is supported by static-exchange (STEX) calculations for the porphin (Pf) and Zn-porphin (Zn-Pf1) molecules. By calculation, four pi* resonances occur for porphin (Pf) and two for Zn-Pf1. Experimentally we detect four resonances for porphin and PfNH, and two for the Zn-complexed ones. They can be assigned to core excitations to a couple of energy split pi* orbitals for each not equivalent N atom. Our calculations justify the observed low pi* intensity as due to an extended delocalization of the pi* orbitals. The NEXAFS investigations on platinum complex/Zn-porphyrinato assembled macrosystems (i.e. Pt-ZnPf1, Pt-ZnPf2 and Pt-ZnPf3) show the influence of the Pt tethers bound to the porphyrin through the ethynyl moiety on the electronic structure of the tetrapyrrolic cycle. (C) 2003 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
