Synthesis and crystal structure of p,σ-complex [Cu3(C17H15N3S)2Br3]∙CH3CN based on 3,4-diphenyl-5-thioallyl-1,2,4-triazole

Novel p,σ-complex Cu 3 ( Dthatr ) 2 Br 3 ]∙CH 3 CN ( 1 ) has been synthesized by the alternating-current electrochemical technique from acetonitrile solution of CuBr 2 and 3,4-diphenyl-5-thioallyl-1,2,4-triazole ( Dthatr ). The structure of compound 1 has been studied by single crystal X-ray diffraction method. The collected diffraction data were processed using CrysAlis RED program. The structure was solved by ShelXT program and refined by least squares method on F 2 by ShelXL program with the following graphical user interface of OLEX 2 . Compound 1 crystallizes in the centrosymmetric space group P 2 1 /с a = 12.1402(4), b = 13.2207(5), c = 24.7408(7) Å, β = 103.853(3) , V = 3855.4(2) Å 3 , Z = 4. Asymmetric unit of the cell contains two crystallographically independent organic molecules and three copper(I) atoms. The Dthatr molecule acts as chelate-bridging ligand, forming acentric organometallic dimers {Cu 2 ( Dthatr ) 2 } 2+ with two seven-membered and one six-membered rings. The Cu1 and Cu2 atoms together with π-coordinated to them two allylic groups are disordered over two sites with an occupancy ratio of 0.800(6) and 0.200(6), and 0.802(6) and 0.198(6), respectively. Cu1A and Cu1B have a trigonal-pyramidal coordination environment, the basal plane of which is occupied by two triazole N atoms and by C=C bond. The apical position of the pyramid is occupied by the Br atom of the planar CuBr 3 2– anion. This anion, similar to FeCl 4 2– (in [Cu 2 ( Pathatr ) 2 ZnCl 4 ]∙2CH 3 CN) and ZnCl 4 2– (in [Cu 2 ( Pathatr ) 2 FeCl 4 ]∙2CH 3 CN), bridges two π-coordinated central atoms of the acentric dimer into island units {Cu 3 ( Dthatr ) 2 Br 3 }. Cu1A and Cu1B atoms also have a similar trigonal-pyramidal coordination environment, but their apical vertices are occupied by halogen atoms of neighboring units {Cu 3 ( Dthatr ) 2 Br 3 }. Such flexibility of the organometallic unit causes the connection of the {Cu 3 ( Dthatr ) 2 } 2+ cations and CuBr 3 2– anions into chains. Keywords: copper(I), π-complex, allyl derivative of triazole, crystal structure.