Abstract
N,N′-Bis[2-(hydroxyiminomethyl)phenyl]oxamide (H4L) provided trinuclear CuIIMIICuII complexes [M{Cu(HL)-(DMF)}2(DMF)2] (MII = Mn 1, Co 2, Ni 3 or Zn 4). The crystal structures of 1-4 have been determined by X-ray crystallography. They are isomorphous and have an oxamidate-bridged trinuclear CuIIMIICuII structure. The CuII resides in a pseudo-macrocyclic framework of (HL)3- comprised of an oxamidate and a hydrogen-bonded dioximate (=N-O⋯H⋯O-N=) groups to form a square-pyramidal structure {Cu(HL)(DMF)} together with a DMF molecule. Two {Cu(HL)(DMF)} entities co-ordinate to a MnII through the oxamidate oxygens to afford a cis octahedral environment about the metal together with two DMF oxygens. The CuII⋯MII intermetallic distance separated by the oxamidate bridge is 5.33-5.49 Å. In the case of 1 and 3 a significant antiferromagnetic interaction operates between the adjacent CuII and MII. The reaction of 1 with MnII in acetonitrile in the presence of KOH and 18-crown-6 formed Mn{Cu(L)}(H2O)4 that has a polymeric structure extended by the dioximate-MnII-dioximate linkage. It is a weak ferromagnet (TC = 5.5 K) exhibiting a weak antiferromagnetic interaction between the ferrimagnetic chains.
Original language | English |
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Pages (from-to) | 64-70 |
Number of pages | 7 |
Journal | Journal of the Chemical Society, Dalton Transactions |
Issue number | 1 |
DOIs | |
Publication status | Published - Dec 1 2001 |
All Science Journal Classification (ASJC) codes
- Chemistry(all)