In vivo anticancer, anti-inflammatory, and toxicity studies of mixed-ligand Cu(II) complexes of dien and its Schiff dibases with heterocyclic aldehydes and 2-amino-2-thiazoline. Crystal structure of [Cu(dien)(Br)(2a-2tzn)](Br)(H2O)

A new series of complexes of the type [Cu(dien)(2a-2tzn)Y2] and [Cu(dienXX)(2a-2tzn)Y2], where dien = diethylenetriamine and dienXX = Schiff dibase of diethylenetriamine formed with 2-furaldehyde (dienOO), 2-thiophenecarboxaldehyde (dienSS), or pyrrol-2-carboxaldehyde (dienNN); Y = Cl, Br or NO3; and 2a-2tzn = 2-amino-2-thiazoline, were synthesized and their structure established by C, H, N and Cu analysis; IR and electronic spectra; magnetic susceptibility; and molar conductivity. The isolated complexes are monomers, paramagnetic, and electrolytes of types 1:1 or 1:2. In both types of solid state complexes, [Cu(dien)(2a-2tzn)Y2] and [Cu(dienXX)(2a-2tzn)Y2], dien and its Schiff dibases are bonded to Cu(II) in a tridentate fashion through 3N atoms. The coordination sphere is completed by the endocyclic nitrogen of the thiazoline moiety and by two Cl, Br, or NO3 groups with distorted octahedral geometry. The proposed structure of these compounds was supported by X-ray analysis of [Cu(dien)(Br)(2a-2tzn)](Br)(H2O). The coordination polyhedron around the copper atom can be described as a distorted square pyramid [Cu(dien)(Br)(2a-2tzn)]+. Its basal plane is occupied by the four nitrogen atoms of the dien and thiazoline ligands with Cu–N distances ranging between 1.996(6) and 2.032(3) Å, and the axial position is occupied by one of the two bromine atoms (Br1) with a Cu1–Br1 bond distance of 2.782(1) Å. The second bromine atom (Br2) is 4.694(2) Å from the copper atom, which exists as a discrete anion and is responsible for the cationic nature of the complex. Results regarding toxicity, antitumor, and anti-inflammatory activities of the investigated compounds are promising and allow the selection of a lead compound for further biological studies.