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Titolo:
P-31 and C-13 NMR studies of a liquid-crystalline cyclotriphosphazene derivative: Orientational characteristics and contrasting shielding anisotropies for inorganic and organic moieties
Autore:
Moriya, K; Suzuki, T; Yano, S; Miyajima, S;
Indirizzi:
Gifu Univ, Fac Engn, Dept Chem, Gifu 5011193, Japan Gifu Univ Gifu Japan5011193 v, Fac Engn, Dept Chem, Gifu 5011193, Japan Inst Mol Sci, Okazaki, Aichi 4448585, Japan Inst Mol Sci Okazaki Aichi Japan 4448585 i, Okazaki, Aichi 4448585, Japan
Titolo Testata:
JOURNAL OF PHYSICAL CHEMISTRY B
fascicolo: 33, volume: 105, anno: 2001,
pagine: 7920 - 7927
SICI:
1520-6106(20010823)105:33<7920:PACNSO>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
PHASE-TRANSITIONS; STATE; ORGANOPHOSPHAZENES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
23
Recensione:
Indirizzi per estratti:
Indirizzo: Miyajima, S Miyajima Shoyu Co Ltd, 2318 Funamiya, Karatsu 8470062, Japan Miyajima Shoyu Co Ltd 2318 Funamiya Karatsu Japan 8470062 pan
Citazione:
K. Moriya et al., "P-31 and C-13 NMR studies of a liquid-crystalline cyclotriphosphazene derivative: Orientational characteristics and contrasting shielding anisotropies for inorganic and organic moieties", J PHYS CH B, 105(33), 2001, pp. 7920-7927

Abstract

P-31 and C-13 NMR studies are reported for a smectic A liquid crystal of haxakis[4-dodecyl(4-biphenoxy)]-cyclotriphosphazene. In an intense magnetic field, the long axes of the biphenylene fragments and the alkyl chains align along the magnetic field, and the cyclotriphosphazene (ctp) ring-normal points preferentially in the same direction. Orientational order parameters for the inorganic moiety (ctp fragment) and that for the organic moiety (biphenylene fragment) are determined independently from the P-31 and C-13 NMRspectroscopies, respectively. The two order parameters are revealed to take the same value, 0.45. The value is smaller than that for the conventionalsmectic A liquid crystals consisting of small organic molecules. Contrasting chemical shift anisotropies are revealed for the motionally averaged fragments: the least-shielding axis for the 31P nucleus lies on the ctp ring normal, while that for the aromatic 13C nucleus lies along the line connecting the two phenylene rings.

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Documento generato il 27/01/20 alle ore 01:33:41