Cupro(I)-π-complexes with 1-allyloxybenzotriazole: Synthesis and crystal structure of CuBF4 · 2C6H4N3(OC3H5) · H2O and CuCF3COO · C6H4N3(OC3H5)

Abstract

The crystals of copper(I) π-complexes CuBF4 · 2C6H4N3(OC3H5) · H2O (I) and CuCF3COO · C6H4N3(OC3H5) (II) were obtained by alternating-current electrosynthesis and studied by X-ray diffraction: I, space group P21/n, a = 10.226(8), b = 13.233(10), c = 16.30(1) A, β = 98.13(1)°, V = 2249(2) A3, Z = 4, R = 0.0705, 577 reflections; I, space group P\( P\bar 1 \) , a = 8.8625(7), b = 9.0647(4), c = 9.1650(5) A, α = 68.37(2)°, β = 85.31(3)°, γ = 69.86(2)°, V = 646(4) A3, Z = 2, R = 0.1354, 2669 reflections. In compound I, the tetrahedrally distorted trigonal pyramidal environment of the copper atom comprises two nitrogen atoms of two organic molecules (L), the C=C bond of another L molecule, and the O atom of the water molecule. Due to the bridging function of L molecule, infinite chains [Cu · 2C6H4N3(OC3H5) · H2O]n are formed in the structure along the y axis. The chains are, in turn, assembled into layers through strong O-H…F hydrogen bonds involving both hydrogen atoms of the water molecule and fluorine atoms of the BF4− anion. In compound II, two bridging oxygen atoms of two trifluoroacetate anions and two copper atoms form a centrosymmetric dimer. The nitrogen atom of the benzotriazole ring of one molecule L and the C=C double bond of the allyl group of the other molecule L complete the distorted coordination tetrahedron of the metal atom. Owing to the bridging function of the L molecule, the [CuCF3COO · C6H4N3(OC3H5)]2 dimers are connected to form infinite double chains associated in a three-dimensional framework by only weak interactions. The replacement of the covalently bonded trifluoroacetate anion by an outer-sphere tetrafluoroborate ion opens up the possibility for metal atom binding to three L molecules simultaneously.