2-Imino-3-allyl-benzothiazole as a pi-Ligand: Synthesis and Crystal Structure of [(CuCl)C10H10SN2], [C10H11SN2+](2)[Cu2Cl4](2-), and [C10H11SN2+](2)[Cu2Br4](2-) pi-compounds

摘要

The reaction of 2-amino-benzothiazole with allyl bromide resulted in a mixture of 2-imino-3-allyl-benzothiazole and 2-imino3-allyl-benzothiazolium bromide.Using such a mixture and copper(II) chloride in acetonitrile solution in alternating-current electrochemical synthesis crystals of the [(CuCI)C10H10SN2] (1) have been obtained. The same procedure, performed in ethanol solution, has led to formation of [C10H11SN2+](2)[CU2CI4(II). In the same manner the bromine derivative [C10H11SN2+](2)[Cu2Br4](2)(III) has been synthesized. All three compounds were X-ray structurally investigated. Lmonoclinic space group P21, a = 13.789(6), b 6.297(3), c = 13.830(6) A, 0 = 112.975(4)degrees, V = H 05.6 (9) A 3, Z 4 for CuCl center dot C10H10 SN2 composition. Compounds II and III are isomorphous and crystallize in triclinic P T space group. 11 a = 7.377(3), b = 8.506(3), c = 9.998(4) A, a = 79.892(10)degrees, l3 = 82.704(13)degrees, y = 78.206(12)degrees, V = 601.9(4) A3, Z = 1. 111 a = 7.329(2), b 8.766(3), c = 10.265(3) A, a = 79.253(9), P = 82.625(9)degrees, gamma 77.963(9)degrees, V = 630.9(3) A3, Z = 1. In the structure I [(CuCl])C10H10SN2] building blocks are bound into infinitive spiral-like chains via strong N-H... Cl hydrogen bonds. In the zwitter-ionic 11 and III compounds copper and halide atoms form centrosymmetric [CU2X4](2-) anions, which are interconnected via N-H... X hydrogen bonds into infinite butterfly-like chains. The strongest Cu-(C=C) Tc-interaction has been observed in structure 1, where copper possesses coordination number 3. Increasing copper coordination number to 4 in 11 as well as replacing chlorine atoms by bromine ones in III suppresses markedly this interaction.