Pregled bibliografske jedinice broj: 76164
Dimerisation and oxygen loss upon crystallisation of nitroso compounds
Dimerisation and oxygen loss upon crystallisation of nitroso compounds // 11th Slovenian-Croatian crystallographic meeting - book of abstracts / Leban, Ivan ; Popović, Stanko (ur.).
Ljubljana: Univerza v Ljubljani, 2002. str. 28-28 (predavanje, nije recenziran, sažetak, znanstveni)
CROSBI ID: 76164 Za ispravke kontaktirajte CROSBI podršku putem web obrasca
Naslov
Dimerisation and oxygen loss upon crystallisation of
nitroso compounds
Autori
Višnjevac, Aleksandar ; Milovac, Srđan ; Šimunić- Mežnarić, Vesna ; Kojić-Prodić, Biserka ; Vančik, Hrvoj
Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni
Izvornik
11th Slovenian-Croatian crystallographic meeting - book of abstracts
/ Leban, Ivan ; Popović, Stanko - Ljubljana : Univerza v Ljubljani, 2002, 28-28
Skup
11th Slovenian-Croatian crystallographic meeting
Mjesto i datum
Bohinj, Slovenija, 27.06.2002. - 30.06.2002
Vrsta sudjelovanja
Predavanje
Vrsta recenzije
Nije recenziran
Ključne riječi
dimerisation ; oxygen loss ; crystallisation ; nitroso compounds
Sažetak
Most of the organic nitroso compounds exist as colourless dimers in solid state, and/or as green or blue monomers in solution.1 Crystallisation process implies simultaneous dimerisation. Nevertheless, these compounds reveal reversible dissociation/association under photochemical conditions in solid state, and as such they represent a simple and effective photochromic system.2 Dimers of p-bromonitrosobenzene (1), p- iodonitrosobenzene (2), p-nitronitrosobenzene (3) and p-methylnitrosobenzene (4) were studied by X- ray crystallography. Unprecedented lack of oxygen atoms in what was expected to be an azodioxy moiety was encountered in all of the presented structures. Furthermore, the structures 3 and 4 (Figs. 1 and 2) reveal disorder of the azo group over two positions, with s.o. 0.70 and 0.30. Two independent positions of nitrogen atoms appeared clearly in a Fourier difference map, whereas it was impossible to resolve discrete positions of disordered C-atoms of the benzene rings which, as a consequence, reveal slightly increased values of displacement parameters. For structure 3, the non- centrosymmetric space group P21 is reported due to a large number of reflections disobeying extinction rules for P21/c (in which, however, refinement converges as well). Molecules of 1 and 2 reveal crystallographic inversion centre at the midpoint of the N-N bond, having half a molecule in an asymmetric unit of the space groups P21/c and Pbcn, respectively. The molecule of 4 is of C1 symmetry, occupying general position.
Izvorni jezik
Engleski
Znanstvena područja
Kemija
POVEZANOST RADA
Projekti:
0098036
Ustanove:
Institut "Ruđer Bošković", Zagreb,
Prirodoslovno-matematički fakultet, Zagreb
Profili:
Biserka Kojić-Prodić
(autor)
Hrvoj Vančik
(autor)
Vesna Šimunić-Mežnarić
(autor)
Srđan Milovac
(autor)
Aleksandar Višnjevac
(autor)