Naslov
Compounds with Oxalate-Bridged Dinuclear Cu^IICu^II and Cu^IINb^V Units: Structures and Magnetism
(Compounds with Oxalate-Bridged Dinuclear Cu^IICu^II and Cu^IINb^V Units: Structures and Magnetismm)

Autori
Perić, Berislav ; Jurić, Marijana ; Giester, Gerald ; Pajić, Damir ; Zadro, Krešo ; Planinić, Pavica ; Brničević, Nevenka

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

Izvornik
Fifteenth Slovenian-Croatian Crystallographic Meeting. Book of Abstracts / Lah, Nina ; Leban, Ivan - Ljubljana : Univerza v Ljubljani, 2006, 43-43

Skup
Fifteenth Slovenian-Croatian Crystalographic Meeting

Mjesto i datum
Jezersko, Slovenija, 15.06.2006. - 18.06.2006

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
dinuclear complexes; oxalate-bridged complexes; copper; niobium; crystal structure; magnetism

Sažetak
The structural and magnetic properties of the two novel compounds: [(Cu(phen)_2)_2(mu-C_2O_4)][Cu(phen)_2(mu-C_2O_4)NbO(C_2O_4)_2]_2 center dot 8H_2O (1) and [(Cu(bpy)_2)_2(mu-C_2O_4)][Cu(bpy)_2(mu-C_2O_4)NbO(C_2O_4)_2]_2 center dot 0.5bpy center dot 7H_2O (2) (phen = 1, 10-phenanthroline, bpy = 2, 2'-bipyridine) was presented. The molecular structures of both compounds consist of a discrete Cu^IICu^II oxalate-bridged dinuclear [(Cu(L)_2)_2(mu-C_2O_4)]^2+ cations (A units) and two Cu^IINb^V oxalate-bridged dinuclear [Cu(L)_2(mu-C_2O_4)NbO(C_2O_4)_2]^- anions (B units) (L = phen, bpy). In 1 a crystallographic inversion centre is located in the middle of the oxalate bridge of the A unit, whereas in 2 an analogous inversion centre is missing. In the A units the copper(II) atoms adopt a tetragonally elongated octahedral coordination with the equatorial planes being perpendicular to the mean planes of the oxalate bridge and parallel to each other. In both structures, similar one-dimensional structural motifs are generated through the ligand stacking interactions, with a difference that one free bipyridine molecule, present in 2, intercalates into one of the motifs. It is shown that the phenanthroline ligand, due to its ability of stacking through the central aromatic ring, causes longer intermolecular Cu...Cu distances than the bipyridine ligand. Structural data are correlated with the magnetic susceptibility measurements (1.8 - 290 K) which show the ferromagnetic exchange interaction between the copper(II) atoms in the A units of both compounds, with J = + 5.9 cm^-1 and + 7.9 cm^-1 for 1 and 2, respectively (J is the magnetic exchange parameter in the isotropic spin Hamiltonian H_(INT) = -JS1xS2).

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

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