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Titolo:
Structure-property dependence of the first hyperpolarisabilities of organometallic merocyanines based on the mu-vinylcarbynediiron acceptor and ferrocene donor
Autore:
Farrell, T; Manning, AR; Murphy, TC; Meyer-Friedrichsen, T; Heck, J; Asselberghs, I; Persoons, A;
Indirizzi:
Univ Coll Dublin, Dept Chem, Dublin 4, Ireland Univ Coll Dublin Dublin Ireland 4 l Dublin, Dept Chem, Dublin 4, Ireland Univ Hamburg, Inst Anorgan & Angew Chem, D-20146 Hamburg, Germany Univ Hamburg Hamburg Germany D-20146 ngew Chem, D-20146 Hamburg, Germany Katholieke Univ Leuven, Lab Chem Biol Dynam, B-3001 Louvain, Belgium Katholieke Univ Leuven Louvain Belgium B-3001 m, B-3001 Louvain, Belgium
Titolo Testata:
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
fascicolo: 9, , anno: 2001,
pagine: 2365 - 2375
SICI:
1434-1948(200109):9<2365:SDOTFH>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
NONLINEAR-OPTICAL PROPERTIES; HYPER-RAYLEIGH SCATTERING; FIRST HYPERPOLARIZABILITY MEASUREMENTS; BOND-LENGTH ALTERNATION; 2ND-HARMONIC GENERATION; 2-PHOTON FLUORESCENCE; ELECTRONIC-STRUCTURE; DIIRON COMPLEXES; NLO RESPONSES; CHROMOPHORES;
Keywords:
nonlinear optical materials; ferrocene; merocyanine; hyper Rayleigh scattering; solvatochromism; bondlength alternation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
74
Recensione:
Indirizzi per estratti:
Indirizzo: Farrell, T Univ Coll Dublin, Dept Chem, Dublin 4, Ireland Univ Coll Dublin Dublin Ireland 4 ept Chem, Dublin 4, Ireland
Citazione:
T. Farrell et al., "Structure-property dependence of the first hyperpolarisabilities of organometallic merocyanines based on the mu-vinylcarbynediiron acceptor and ferrocene donor", EUR J INORG, (9), 2001, pp. 2365-2375

Abstract

In order to investigate the structure-property relationship of nonlinear optical materials, a series of organometallic chromophores were synthesised utilising the [Fe-2(B-C5H5)(2)(CO)(2)(mu -CO)(mu -C-)](+) electron-accepting moiety and the ferrocenyl group, Fc, as the electron donor. The pi -linker between these two termini was systematically modified and the mutual electronic communication between them was determined using IR, NMR, and electronic absorption spectroscopy. An X-ray structure determination of [Fe-2(eta -C5H5)(2)(CO)(2)(mu -CO)(muC-CH=CH-CH=C(Cl)-Fc)][BF4] confirmed the strong electronic interaction between the donor and the acceptor with reduced pi -bridge bond-length alternation. The nonlinear optical properties of these complexes were examined using the hyper Rayleigh scattering technique. The experimental first hyperpolarisabilities are some of the highest obtained for ferrocenyl chromophores and, significantly, no enhancement was found due to two-photon absorption fluorescence. When polyene linkers -(CH=CH)(n)- are used, the values for beta (0) increase with a ca. n(1.5) dependence with no sign of saturation up to n = 4. However, the highest values for beta andbeta (0) were obtained for linkers which contained an aromatic ring as opposed to pure polyenes and in this respect a benzene ring was more effectivethan a thiophene or furan. Consequently, the higher beta and beta (0) are not exhibited by those merocyanines with the highest values for lambda (max). It is concluded for these compounds that a low excitation energy E-eg and a large transition moment M for the electronic excitation are less important than a large change in the dipole moment Delta mu (eg). Furthermore, a chloro substituent on the olefinic double bond proximate to the ferrocenyl group has a dramatic effect on the beta and beta (0) values.

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Documento generato il 04/12/20 alle ore 09:29:33