Synthesis, characterization, crystal structures and magnetic properties of di- and polynuclear bis(μ-3-pyridin-2-yl-1,2,4- triazolato)copper(II) compounds containing N-methylimidazole, pyrazole or 4,4′-bipyridine as co-ligands

Synthesis, Crystal Structure, Spectroscopic and Magnetic Properties of an Unprecedented Three-Dimensional CuII Coordination Compound of 1,2-Bis(1,2,4-triazol-4-yl)ethane

“…The UV/Vis spectrum shows a broad asymmetric band with a maximum situated at 11.6 ϫ 10 3 cm Ϫ1 and a shoulder at 9.3 ϫ 10 3 cm Ϫ1 , which is in agreement with the presence of both CuN 6 and CuN 5 O chromophores, as well as with the tetragonal distortion of the Cu II octahedra. [45] There is no evidence for a strong deviation from T d symmetry for the noncoordinating perchlorate anions, as is indicated by the strong ν 3 absorption at 1102 cm Ϫ1 and the ν 4 at 623 cm Ϫ1 observed in the infrared spectrum.…”

“…Figure 1. Atomic displacement ellipsoid drawing [57] (50% probability level) and atomic labeling system showing the asymmetric unit of [Cu 3 (btre) 5 1.985(7) Cu3ϪN611 [d] 2.030 (6) Marked atoms are generated by symmetry operations:…”

“…[8] It is, however, in contrast to the geometry of the central Cu II ion in the linear trinuclear compound [Cu 3 (metz) 6 [42] [ 44] where it appears that the dynamic JahnϪTeller distortion results in a completely regular octahedral coordination about the Cu II ion octahedron, with six relatively short CuϪN distances of 2.14(5) Å .…”

“…Cu1ϪO1ϪH···O2 (Ϫ1 ϩ x, 1 ϩ y, z) Ϫ Cu3 (Ϫ1 ϩ x, 1 ϩ y, z) gives a CuϪCu distance of 6.784(1) Å . 0.81(5) 1.99(6) 2.729(7) 151(7) O1ϪH1B···O21 [b] 0.81 (7) 2.15 (7) 2.900(9) 154(7) O2ϪH2A···N112 [c] 0.81 (4) 2.23 (7) 2.931(8) 146(7) O2ϪH2B···O31 [d] 0.80 (9) 2.02(9) 2.828(9) 178(8) O2ϪH2B···O33 [d] 0.80 (9) 2.59(8) 3.057(9) 119(7) O3ϪH3A···O13 [b] 0.82 (6) 2.29(6) 3.060(8) 157(7) O3ϪH3A···O14 [b] 0.82 (6) 2.36 (7) 3.046(8) 142(6) O3ϪH3B···N212 0.81(7) 2.11(7) 2.913(8) 168 (7) Marked atoms are generated by symmetry operations:…”

Electron Paramagnetic Resonance Studies on cis-catena-sulphatoaqueotris (imidazole) copper (II) Exchange interactions mediated thro’sulphato bridges

“…On the other hand, EPR allows one to evaluate weak exchange from data taken at high temperature. For example, weak magnetic interactions in transition metal complexes bridged by intervening ligands such as carboxylate [11,14,19], triazole [20,21], azide [7,19], pyrazole [20][21][22][23][24] etc have been studied by EPR. Tetraoxo anions such as phosphate, arsenate, vanadate, sulphate and molybdate are known to bridge mental centers [25].…”