Copper(II) chloride/1-methylbenzotriazole chemistry: influence of various synthetic parameters on the product identity, structural and magnetic characterization, and quantum-chemical studies

Transformation of a CuII Thiazolo‐1,2,4‐triazine Derivative from a Metastable Coordination Network to a Monomer in Solution and Vapor Conditions

“…The magnetic coupling in dichloro-bridged Cu 2+ complexes is very sensitive to the Cu-Cl-Cu angles, Cu-Cl distances, and distortions around the Cu 2+ ions, dramatically varying from antiferromagnetic to ferromagnetic interactions with small structural changes. [42][43][44][45][46][47] The ferromagnetic coupling between the Cu 2+ ions is also found in dichlorobridged dimers [31,32,[43][44][45][46][47] and chains [14,34] reported in the literature. In this work, two Cu-Cl-Cu angles of 5a are in the middle of the range for bis(μ-chloro)Cu 2+ dimer complexes, [31] which have the possibility of ferromagnetic and antiferromagnetic interactions in the intrachain structure.…”

“…Several network types, III, IV, and V of bis(μ-chloro)Cu 2+ complexes have been reported and the linear type III is well known; (CuCl 2 L 2 ) n [33,34] and (Cu 2 Cl 4 L 2 ) n . [14,35] The ladder formation of IV and the zigzag formation of type V have also been reported (CuCl 3 LЈ) n (LЈ = N 2 H 5 [36] ) and (CuCl 2 LЈЈ) n [LЈЈ = bipyridine [37] or di(2-pyridyl) ketone [38] ], respectively, where two bidentate ligands L ЈЈ are coordinated to each Cu 2+ ion. In this work, the geometry around the Cu 2+ center in 5a is type II, and, to the best of our knowledge, the network formed is new and classified as type VI (Figure 3, b).…”

“…The geometries of Cu 2+ can be classified as square pyramidal I and trigonal bipyramidal II (Figure 3, a), which have been discussed in relation to their magnetic properties [14,15,31] and theoretical analysis [32] of the dimer. Several network types, III, IV, and V of bis(μ-chloro)Cu 2+ complexes have been reported and the linear type III is well known; (CuCl 2 L 2 ) n [33,34] and (Cu 2 Cl 4 L 2 ) n .…”

“…The four kinds of Cu-Cl bond lengths mentioned above show that Cl ion sites of the bridging center and the average bridging bond lengths are remarkably short compared with the dimers. For example, in the work on a dichloro-bridged dimer with a trigonal bipyramidal [14] is good example for comparison and is a molecular ferromagnet in which the chains are coupled antiferromagnetically: χT increases upon cooling at 20 K (0.62 cm 3 K mol -1 ) and then decreases. In this complex, the Cu-Cl-Cu bond angle is 95.6(1)°and the Cu-Cl bond lengths are short [2.261(1) and 2.534(1) Å], giving a Cu···Cu distance of 3.556(1) Å.…”

“…[9,10] However, the coordination mode of these heterocyclic compounds is unclear for two reasons: (i) few structural characterizations of the coordination complexes have been carried out [11,12] and (ii) dynamic exchange reactions of the coordination site occur between the multiple donor species depending on the external conditions. [13][14][15] Therefore, we examined some model com-of 5a decreased according to the color change. The XRD pattern of 5a also changed to a new aggregation state, ascribed to the disproportionation of the 1D network to form a mononuclear complex and a solvated metal ion in the crystalline state.…”