Ringing the changes in Feiii/Ybiii cyclic coordination clusters

Abstract

Five [FeIIImYbIIIn] Cyclic Coordination Clusters (CCCs) which show completely different arrangements of their cyclic cores have been synthesised and characterised. These represent five out of seven compounds which were obtained by fine-tuning the reaction conditions (FeIII-source, LnIII-salt, chiral/nonchiral aminoalcohol ligands) used previously to synthesise the non-cyclic [Fe2Yb2(OH)2(teaH)2(O2CPh)6] compound 1. Thus the five new CCCs [Fe5Yb3(μ3-OH)(teaH)7(O2CPh)8](CF3SO3)·10MeCN (m = 5; n = 2, 2), [Fe4Yb2(μ-OH)(μ-OMe)2(Me-teaH)4(O2CPh)7]·3CH3CN (m = 4; n = 2, 3), [Fe3Yb2(μ-OH)(Me-teaH)4(O2CPh)6]·MeCN (m = 3; n = 2, 4), [Fe4Yb2(Me-tea)4(Me-teaH)2(OTs)2]·MeCN·3MeOH (m = 4; n = 2, 5) and [Fe10Yb10(Me-tea)10(Me-teaH)10(NO3)10]·21MeCN (m = 10; n = 10, 6) as well as the binuclear complex [Yb2(tipH2)2(O2CPh)4] (7) are reported. The formation of compounds 2, 3 and 4, which were obtained using [Fe3O(O2CCPh)6(H2O)3]+ as the source of FeIII, can be rationalised in terms of cleaving the triangular {FeIII3O} starting material into mononuclear and dinuclear FeIII/benzoate species. Furthermore, it was found that for compounds 3–6, the interplay of ligand chirality, hydrogen-bonding interactions and the nature of anionic species present are decisive directional influences on the resulting nature of the cyclic compounds.