Naslov
Solid state NMR investigation of two niobium clusters: [Nb6Br12(H2O)6][HgBr4]•12H2O and Nb6Cl12(H2O)4(OH)2]•4H2O

Autori
Perić, Berislav ; Planinić, Pavica ; Požek, Miroslav ; Bosiočić, Marko ; Gautier Régis

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
The twentieth Croatian-Slovenian crystallographic meeting - CSCM20, Book of Abstracts and Programme / Cetina, Mario ; Matković-Čalogović, Dubravka ; Popović, Stanko ; Skoko, Željko ; Štefanić, Zoran ; Višnjevac, Aleksandar - Zagreb : Hrvatska akademija znanosti i umjetnosti (HAZU) ; Hrvatska Kristalografska Zajednica, 2011, 33-33

Skup
The twentieth Croatian-Slovenian crystallographic meeting - CSCM20

Mjesto i datum
Baška, Hrvatska, 15.06.2011. - 19.06.2011

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
ssNMR; niobium; clusters

Sažetak
A significant part of niobium chemistry is devoted to investigations of compounds containing edge-bridged cluster units [(Nb6Xi12)La6] (Xi = Cl−, Br− ; La = Cl−, Br−, H2O, etc.). Although a limited number of 93Nb solid state NMR studies exist, such data are missing for cluster compounds. We have chosen two compounds of known structures: [Nb6Br12(H2O)6][HgBr4]•12H2O1 (1) and [Nb6Cl12(H2O)4(OH)2]•4H2O2 (2) to obtain referent solid state NMR data for [Nb6Br12]2+ and [Nb6Cl12]2+ cluster units, respectively. Such data are important in further investigation of mixed chloride/bromide clusters, especially when the samples are not of a good enough quality for the single-crystal X-ray diffraction study. According to the positions of non-hydrogen atoms in the structure of 1, hydrogen atoms were added to complete the nearest possible hydrogen bonds.3 In the structure of 2, hydrogen atoms were added according to the literature model.2 Both structures were optimized by the CASTEP program, 4 using built-in ultrasoft pseudopotentials and DFT (PBE functional). Solid state NMR parameters were calculated on such optimized structures by the CASTEP-NMR program, 4 using the GIPAW-DFT approach and the same pseudopotentials and functional. A very good agreement between experimentally determined and calculated NMR parameters was achieved for the quadrupole coupling constant Cq and the asymmetry parameter ηQ, especially for cubic compound 1.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

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