Abstract
The 1 : 2 reactions of 4,6-bis[N,N-bis(2'-pyridylmethyl) aminomethyl]-2-phenylpyrimidine (L-Me) and Mn-II, Co-II, Ni-II and Cu-II chloride salts in MeOH gave the tetranuclear complexes [Mn-4(II)(L-Me)(2)Cl-8]center dot 2H(2)O (1), Co-4(II)(L-Me)(2)Cl-8 center dot 10H(2)O (2), [Ni-4(II)(L-Me)(2)Cl-4]Cl-4 center dot 8H(2)O (3) and [Cu-4(II)(L-Me)(2)Cl-6]Cl-2 center dot 8H(2)O (4), respectively. X-ray crystal structure determinations carried out on three of the complexes revealed that in the case of Ni-II (3') the L-Me ligand is bound in the expected bis-tetradentate fashion, bridging the encapsulated pair of Ni-II centers via the pyrimidine ring, and that two pairs of chloride anions bridge a pair of such dimetallic units, affording a closed rectangular tetranuclear core overall. In contrast, in the case of Mn-II (1') and Cu-II (4') only one binding pocket of the L-Me ligand strand binds in the expected tetradentate manner, whilst the other binds in a terdentate manner as one pyrimidine nitrogen atom does not bind, so in these cases the pyrimidine moiety does not bridge the metal centres, resulting instead in 'extended', linear tetranuclear assemblies.