Ligand influences on the structures of copper(II) vanadates. Structures and magnetic properties of [Cu_3(triazolate)_2V_4O_(12)], [Cu_2(tpyrpyz)_2V_4O_(12)] (tpyrpyz=tetrapyridylpyrazine) and [Cu_2(pyrazine)V_4O_(12)]

摘要

The hydrothermal reactions of Cu(NO_3)_2 and Na_3VO_4 with a series of bridging organonitrogen ligands results in the preparation of a bimetallic oxide amterial of the Cu/V/O/ organonitrogen family with structures incorporating the {V_4O_(12)}~(4-) cyclic cluster as an architectural motif. The overall structures of these materials reflect in part the geometric and coordination influences of the ligands. Thus, architectural motif. The overall structures of these materials reflect in part the geometric and coordination influences of the ligands. Thus, [Cu_3(triazolate)_2V_4O_(12)] (1) is three-dimensional, constructed from {Cu_3(triazolate)_2}_n~(+4n) chains linked through {V_4O_(12)}~(4-) clusters. In contrast, [Cu_2(tpyrpyz)_2V_4O_(12)] (2) is one-dimensional and exhibits binuclear {Cu_2tpyrpyz)_2}~(4+) units linked through {V_4O_(12)}~(4-) clusters. The structure of [Cu(pyrazine)V_4O_(12)] (3) is also three-dimensional, resulting from a complex connectivity patterns between {V_4O_(12)~(4-) and {Cu_2)pyrazine)}~(4+) cluster subunits. The magnetic properties of 1-3 are discussed and related to their structures. Crystal data: C_2H_2Cu_(1.5)N_3O_6V_2 (1): triclinic P1, a=7.569(2), b=-7.817(2), c=8.422(2) A, α=62.998(4), β=64.744(4), γ=66.963(5)°, V=398.3(2) A~3, Z=2; C_(24)H_(18)CuN_6O_7v_2 (2): triclinic P1, a=9.5420(7), b=11.0396(8), c=12.948(1) A, α=72.948(1)°, β=88.866(1)°, γ=70.439(1)°, V=1206.9(2) a~3, Z=2; C_2H_2CuNO_6V_2 (3): triclinic P1, A=7.4515(5), B=7.4727(5), C=7.6274(5) A, α=88.775(1)°, β=62.957(1)°, γ=65.404(1)°, V=336.49(4) A~3, Z=2.