Synthesis and crystal structure of mixed halide Cu(I) complexes with 1,3-benzimdazolone

Abstract

By a direct reaction of 1,3-allylbenzimidazolone in ethanol medium with copper(II) halogenides under alternate current technique conditions with copper wire electrodes were obtained and X-ray single crystal method structurally characterized ( Agilent Gemini A diffractometer) three new isostructural pi-complexes of [C 7 H 4 N 2 O(C 3 H 5 ) 2 Cu 2 X 2 ] composition: space group , Z = 2, X= 0,77Cl/0,33Br ( I ) – a = 8.358(3), b = 9.683(3), c = 9.749(3) A, α = 85.04(3), β = 75.96(3), γ = 70.39(3)°, V = 721.1(4) A 3 , r calc. = 1.99 g/cm 3 , m( MoK a ) = 4.48 mm −1 , q max. = 36.8°, 9089 measured, 4927 used reflections, R ( F 2 ) = 0.057, S = 1.12; X= 0.25Cl/0,75Br ( II ) – a = 8.3294(8), b = 9.8050(11), c = 9.8368(5) A, α = 85.572(6), β = 76.528(6), γ = 70.931(9)°, V = 738.39(12) A 3 , r calc. = 2.16 g/cm 3 , m( CuK a ) = 9.10 mm −1 , q max. = 73.4°, 10408 measured, 2879 used reflections, R ( F 2 ) = 0.040, S = 1.03; X= Br ( III ) – a = 8.3086(3), b = 9.8417(3), c = 9.8642(4) A, α = 85.739(3), β = 76.780(3), γ = 71.049(3)°, V = 742.66(5) A 3 , r calc. = 2.24 g/cm 3 , m( MoK a ) = 8,24 mm −1 , q max. = 29.9°, 11904 measured, 3692 used reflections, R(F 2 ) = 0.020, S = 1.06. Structures were solved by direct methods and refined by full matrix least-squares method on F 2 by SHELXT and SHELXL-2014 with following graphical user interfaces of OLEX 2 . In a crystal structure of the compounds I–III two structurally independent copper atoms possesses trigonal-pyramidal coordination environment consisted of C=C bonds of both allylic groups of organic ligands and halide or oxygen atoms. Due to bridging function of halogenides anions metal coordination polyhedra connected into tetrameric topological units. Last due to coordination of allylic groups of 1,3-dyallylbenzimidazolone with crystallographically non equivalent copper(I) center metal coordination polyhedron linked to infinite chains {L 2 Cu 4 Х 4 } connected by very week C–H…Hal(O) bonds. Keywords : benzimidazolon, copper(І), pi-complexes, crystal structure.