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Titolo:
Ground and excited states of zinc phthalocyanine studied by density functional methods
Autore:
Ricciardi, G; Rosa, A; Baerends, EJ;
Indirizzi:
Univ Basilicata, Dipartimento Chim, I-85100 Potenza, Italy Univ Basilicata Potenza Italy I-85100 mento Chim, I-85100 Potenza, Italy Free Univ Amsterdam, Afdeling Theoret Chem, NL-1081 HV Amsterdam, Netherlands Free Univ Amsterdam Amsterdam Netherlands NL-1081 HV terdam, Netherlands
Titolo Testata:
JOURNAL OF PHYSICAL CHEMISTRY A
fascicolo: 21, volume: 105, anno: 2001,
pagine: 5242 - 5254
SICI:
1089-5639(20010531)105:21<5242:GAESOZ>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
MAGNETIC CIRCULAR-DICHROISM; VAPOR ABSORPTION SPECTRA; EXCITATION-ENERGIES; OPTICAL-PROPERTIES; ELECTRONIC-STRUCTURE; STATISTICAL AVERAGE; ARGON MATRIX; IMPLEMENTATION; APPROXIMATION; MOLECULES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
52
Recensione:
Indirizzi per estratti:
Indirizzo: Rosa, A Univ Basilicata, Dipartimento Chim, Via N Sauro 85, I-85100 Potenza, Italy Univ Basilicata Via N Sauro 85 Potenza Italy I-85100 tenza, Italy
Citazione:
G. Ricciardi et al., "Ground and excited states of zinc phthalocyanine studied by density functional methods", J PHYS CH A, 105(21), 2001, pp. 5242-5254

Abstract

The first time-dependent DFT study of the excited states of ZnPc is presented. The theoretical results provide an accurate description of the UV-vis and vacuum-UV spectra and prove to be in excellent agreement with gas-phasespectra and generally in line with deconvolution analyses of solution and Ar/matrix absorption and MCD spectra. The nature and intensity of the main spectral features are highlighted and interpreted on the basis of the ground state electronic structure of the complex. A fragment approach where the four benzopyrrole rings and the aza bridges are taken as building blocks has proven to be a very important tool to fully understand the energy and composition of the MOs involved in the transitions and, from these, the excitation energies and intensities. The Gouterman a(1u) orbital is the HOMO and the assignment of the Q band is conventional and uncontroversial. The B band comprises five E-u excitations, whose positions and intensities are in very good accordance with the deconvolution of the experimental absorption band performed with the help of MCD spectra. However, this deconvolution invokes Jahn-Teller splitting of the E-u states which we have not calculated. We find at the red edge of the B band the weak 2nd pi --> pi* transition andat the blue edge the weak n --> pi* transition which have been identified in the experiments. We do not confirm at low energy, in the tail of the Q band (the ("Q(02)") region) an electronic origin for the band which has beensuggested to arise from the lowest z-polarized n --> pi* transition. This transition is predicted by our calculations to be very weak and to lie in the B band region. The energies and intensities of the higher excitations are in excellent agreement with the UV N and L bands and with the far UV C and X bands. The predicted level pattern of the lowest triplet excited statesfits in with phosphorescence data available and excited-state absorption spectra.

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Documento generato il 29/03/20 alle ore 17:46:51