The synthesis of small azamacrocycles bearing pendant aromatic functionalities.: The crystal structures of [Cu(L1)2](PF6)2, [(L1)CuCl2], [Cu(L6)(NO3)2] and [Cu2(L7-H)2(OH2)2](PF6)2•3H2O (L1 = N-(mesitylethyl)-1,4,7-triazacyclononane, L6 = N-(4-hydroxymethylbenzyl)-1,4,7-triazacylcononane, L7 = N-(4-benzylcarboxylic acid)-1,4,7-triazacylcononane)

A simple synthetic procedure for the mono- or di-functionalization of tri- and tetra-azamacrocycles with electron rich arenes has been developed. Specifically, 1,4,7-triazacyclononane (tacn), 1,4,7, 10-tetraazacyclododecane (cyclen) and 1 4,8,11-tetraazacyclotetradecane (cyclam) react with 2,4,6-trimethylstyrene in the presence of n-butyllithium to give, respectively N-(mesitylethyl)-1,4,7-triazacyclononane (L-1), N-(mesitylethyl)-1,4,7,10-tetraazacyclododecane (L-4), and N-(mesitylethyl)-1,4,8,11-tetraazacyclotetradecane (L-5). In contrast, when styrene itself or p-vinylanisole are used as the Michael acceptor with 1,4,7-triazacyclononane. the N',N" product is formed, respectively N',N"-bis(phenylethyl)-1,4,7-triazacyclononane (L-2) and N',N"-bis(p-methoxyphenylethyl)-1,4,7-triazacyclononane (L-3). Using conventional mono-functionalization techniques, the phenyl derivatives N-(4-hydroxymethylbenzyl)-1,4,7-triazacyclononane (L-6) and N-(4-benzylcarboxylic acid)-1, 4,7-triazacyclononane (L,) have also been synthesised. A series of transition metal complexes of L-1 to L-7 with Ni(II), Cu(II), Zn(II) and Co(II) have been prepared. The X-ray crystal structures of [Cu(L-1)(2)](PF6)(2), [(L-1)CuCl2], [Cu(L-6)(NO3)(2)] and [Cu-2(L-7-H)(2)(OH2)(2)](PF6)(2).3H(2)O are described. In all of these complexes, coordination to the metal takes place through the macrocycle nitrogens. The crystal structure of [Cu-2(L-7-H)(2)(OH2)(2)](PF6)(2).3H(2)O reveals that it is a coordinate-polymeric material. Attempts to coordinate the pendent arenes to Rh(I) are discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.