摘要:
Novel cationic-anionic {[Co-II(NCS)L-S vertical bar(n+)[X](n-)} X = [V6O11(CH3O)(8)](2-), [Co-II(NCS)(4)](2-) (1 and 2) and neutral [Co-II(NCS)(2)L-S] (3) complexes have been isolated in one pot synthesis from [Co-0-L-VOSO4-NH4SCN] (L = 1-hydroxymethyl-3,5-dimethylpyrazole) system. The anion [(V2V4O11)-V-IV-O-V(CH3O)(8)](2-) was found to be a new mixed valence Lindqvist type cluster. The redox reactions resulted in atypical compositions and structures of the products as well as in an in situ formation of tris(3,5-dimethylpyrazolylmethyl)amine (L-S), which is a scorpionate-type ligand. The coordination numbers of cobalt(II) in the species were found to be five (1), five and four (2) and six (3). The compounds were characterized by analytical, spectroscopic (FT-IR and UV-Vis) and X-ray methods. For the complex containing two different transition metals (1) and that with one transition metal but in two different geometrical environments (2), the digital filtration method applied made it possible to elucidate two independent crystal fields. (c) 2012 Elsevier Ltd. All rights reserved.