Nuclearity growth towards Ni(ii) cubane in self-assembly with 2-hydroxymethyl pyridine (hmpH) and 5-ethoxycarbonyl-2-hydroxymethyl pyridine (5-ehmpH)

Abstract

Self-assembly of NiX2 (X = Br or OAc) with 2-hydroxymethyl pyridine (hmpH) and 5-ethoxycarbonyl-2-hydroxymethyl pyridine (5-ehmpH) results in six new Ni(ii) complexes viz. [Ni(hmpH)2(H2O) 2]Br2 (1), [Ni4(hmp)4(-OAc) 4] (2), [Ni2(-Br)2(5-ehmpH)4]Br 2·0.33MeCN·0.67H2O (3), [Ni(5-ehmpH) 3]Br2·0.33MeOH (4), [Ni4(5-ehmp) 4(H2O)4Br4] (5) and [Ni 4(5-ehmp)4(-OAc)2(OAc)2(H 2O)2] (6), all of which have different chemical compositions and structures. Complexes 2, 5 and 6, however, share a common cubane [Ni4O4] core in which the deprotonated alkoxypyridine serves as a bridge-chelate. The others (viz.1, 3, 4) are mono- or dinuclear with the alkoxypyridine remaining in its native acid form. © 2011 The Royal Society of Chemistry.