Synthesis, characterization, crystal structure and reactivity of the vanadium(V) monoperoxo complex with tetradentate N-(carbamoylethyl)iminodiacetate as heteroligand

From water-ethanol solutions of MVO3-H2O2-H(2)ceida, where M is K+ or NH4and H(2)ceida is N-(carbamoylethyl)iminodiacetatic acid, the red crystallin e complexes of vanadium(V) of composition M[VO(O-2)ceida]. xH(2)O (x = 2 fo r M = K+ and x = 1 for M = NH4+) were prepared. The course of thermal decom position of the potassium salt enabled us to isolate also the anhydrous K[V O(O-2)ceida] from the dihydrate. The X-ray structure analysis of K[VO(O-2)c eida]. 2H(2)O revealed a mononuclear structure of the complex anion with a typical pentagonal bipyramidal arrangement around vanadium. The heteroligan d is coordinated as a tetradentate ceida(2-) ion via imino nitrogen, two ca rboxylic oxygens and oxygen from the carbamoyl group, thus forming two five - and one six-membered chelate rings. The V-51 NMR spectra of aqueous solut ions (pH 3.1-4.9) exhibiting a single peak at approx. -580 ppm showed that the complex anion probably maintains its structure in solution upon dissolu tion. The reactivity of the complex anion in the oxygen transfer reaction f rom the peroxo ligand to the sulphur in the thiolato complex of Co(III) was studied. The reactivity, thermal stability and the crystal structure are c ompared with those for other vanadium(V) monoperoxo complexes with heteroli gands containing an O3N-donor set. (C) 1998 Elsevier Science Ltd. All right s reserved.