Delocalized TCNQ Stacks in Nickel and Copper Tetraazamacrocyclic Systems

Abstract

New derivatives of formula [M(dieneN4)](TCNQ)3, M = Ni or Cu and dieneN4 = cis- or trans-hexamethyltetraazacyclotetradecadiene, have been obtained. The TCNQ units show electronic delocalization and formation of 1D stacks, with no direct interactions with the metal cations. The stack is not uniform and can be seen as formed by trimeric dianions (TCNQ)3(2-). The electronic delocalization favors the conductivity in these materials, which behave as good semiconductors. The crystal structures of the trans derivatives have been solved: [Ni(transdieneN4)](TCNQ)3, triclinic, P-1, a = 8.809(2) A, b = 10.896(2) A, c = 13.727(2) A, alpha = 103.04(1) degrees, beta = 101.23(2) degrees, gamma = 109.37(2) degrees, Z = 1; [Cu(trans-dieneN4)](TCNQ)3: triclinic, P-1, a = 7.872(1) A, b = 9.840(1) A, c = 14.819(1) A, alpha = 92.32(1) degrees, beta = 95.05(1) degrees, gamma = 95.66(1) degrees, Z = 1.