The structures of some (hexamethyl-1,5,9,13-tetraazacyclohexadecadiene)copper(II) compounds

The structure of the crystalline azamacrocyclic product formed by reaction of bis(propane-1,3-diamine)copper(II) perchlorate with acetone has been determined as N-rac-(6,8,8,14,16,16-hexamethyl-1,5,9,13-tetraazacyclohexadeca-5,13-diene)copper(II) · N-meso-(6,8,8,14,14,16-hexamethyl-1,5,9,13-tetraazacyclohexadeca-5,16(1)-diene)copper(II) perchlorate, with the cis, 5,16(1)-diene, and trans, 5,13-diene, isomeric cations co-crystallised. The structures of three compounds crystallised from solutions of this mixture have been determined. N-rac-(6,8,8,14,14,16-hexamethyl-1,5,9,13-tetraazacyclohexadeca-5,16(1)-diene)copper(II) tetrachlorozincate has an irregular flattened tetrahedral coordination geometry with trans-N-Cu-N angles of 139.27(8)° and 155.94(8)°. (Hexamethyl-1,5,9,13-tetraazacyclohexadecadiene)(thiocyanato-N)copper(II) perchlorate has twofold symmetrical square-pyramidal cations. A (μ-cyano)-tetracyanonickelate(II) compound has two (hexamethyl-1,5,9,13-tetraazacyclohexadecadiene)copper(II) cations each with a single axially coordinated tetracyanonickelate(II) group. The compounds, except for the tetrachlorozincate(II) salt, show disorder in the location of the imine functions and axial methyl substituents, attributed to co-crystallisation of enantiomers for the N-rac-trans isomer and/or of rotated arrangements of the N-meso-cis isomer. For the thiocyanato and tetracyanonickelato compounds this disorder precluded unambiguous assignment of configuration.

Bis(propane-1,3-diamine)copper(II) perchlorate reacts with acetone to form both the trans-diimine, (6,8,8,14,16,16-hexamethyl-1,5,9,13-tetraazacyclohexadeca-5,13-diene)copper(II), and cis-diimine, (6,8,8,14,14,16-hexamethyl-1,5,9,13-tetraazacyclohexadeca-5,1(16)-diene)copper(II) macrocyclic cations. The structures of [Cu(Me6[16]diene)](ClO4)2, N-rac-[Cu(cis-Me6[16]diene)][ZnCl4], [Cu(Me6[16]diene)(NCS)]ClO4 and [Cu(Me6[16]diene)(μ-NC)Ni(CN)3] · H2O are reported.Figure optionsDownload as PowerPoint slide