Naslov
Association of copper(II) isonicotinamide moieties via different anionic bridging ligands : Two paths of ferromagnetic interaction in the azide coordination compound

Autori
Đaković, Marijana ; Jagličić, Zvonko ; Kozlevčar, Bojan ; Popović, Zora

Izvornik
Polyhedron (0277-5387) 29 (2010), 8; 1910-1917

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
copper(II); isonicotinamide; azide; thiocyanate; sulfate; crystal structures;

Sažetak
Three isonicotinamide (isn) copper(II) complexes with different bridging ligands, azide, thiocyanate and sulfate, have been prepared. The molecular structure of [Cu2(μ-1, 1- N3)2(μ-1, 3-N3)2(isn)2]n (1) is composed of binuclear species, Cu2(μ-1, 1-N3)2(isn)2, interconnected by an additional four azide bridges in the end-to-end mode (1, 3). This gives a CuN4N square-pyramidal coordination sphere around each copper(II) ion. A trans mononuclear octahedral coordination sphere CuN4S2 is present in [Cu(μ-N, S-NCS)2(isn)2]n (2), with thiocyanato ligands serving as bridges between the adjacent Cu(isn)2 moieties. The third anionic ligand, i.e. sulfate, in {; ; ; [Cu(μ-O, O’-SO4)(H2O)(isn)2]·2H2O}; ; ; n (3) completes the CuO2N2O square-pyramidal coordination sphere, and thus enables bridging between the mononuclear Cu(H2O)(isn)2 moieties. The ligands that bridge the principal building blocks, i.e. binuclear in (1) and mononuclear in (2) and (3), connect the axial ligands with the equatorial positions of the copper(II) coordination spheres in all three cases. A ferromagnetic interactionFM is found for (1), while (2) and (3) are paramagnetic. Therefore, the key structural difference between (1) on one hand, and (2) and (3) on the other, is found in the anionic ligand, serving in (1) also as the intra-binuclear bridge, showing the main path (J1) for the FM interaction. Additionally, the inter-binuclear pathway in (1) gives another contribution (J2) to the whole FM interaction seen herein (J1 = 18.5 cm–1, J2 = 4.9 cm–1).

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA