Dicopper(II) complexes of a binucleating N4 macrocycle containing mono- and di-atomic bridges; magnetic interactions mediated by alkoxo- and diaza-bridging ligands. Crystal structures of [Cu2(L1)(pz)2][ClO4]2, [Cu2(L1)(OEt)2(NCS)2], and [Cu2(L1)(OMe)2(MeCN)2][BPh4]2
1988
Dicopper(II) complexes of 20-membered N4 binucleating macrocycles L1–L3 derived by a cyclic [2 + 2] condensation of diformylthiophene or diformylfuran with the appropriate diamine have been synthesised and characterised by analytical, spectroscopic, magnetic, and X-ray diffraction methods. A pair of bridging ligands, either alkoxo, OR–(R = H, Me, or Et), or diaza (pyrazolate or 1,2,4-triazolate), links the CuII ions. The crystal structure of three compounds [Cu2(L1)(pz)2][ClO4]2(1), [Cu2(L1)(OEt)2(NCS)2](6), and [Cu2(L1)(OMe)2(MeCN)2][BPh4]2(7) have been determined by X-ray diffraction (Hpz = pyrazole). In structures (6) and (7) the copper(II) ions have a trigonal-bipyramidal environment, with ethoxy [(6)] or methoxy [(7)] bridges in a position axial to one CuII and equatorial to the other. Despite the parallel disposition of the dz2 magnetic orbitals, strong antiferromagnetic superexchange is observed for this and the other parallel-planar alkoxobridged dimer described. In structure (1), the copper co-ordination environment is square planar, with cis disposed pyrazolate bridges. Moderate antiferromagnetic exchange is present in (1) and the other diaza compounds, and well defined triplet e.s.r. spectra are observed.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
0
References
36
Citations
NaN
KQI