Molecular Oxygen Insertion in Benzylcobaloximes with Mixed Dioximes
摘要:
The complexes ArCH2CO(gH)(dpgH)Py have been synthesized and characterized by NMR. Molecular oxygen insertion into the Co-C bond in ArCH2CO(L)(dpgH)Py (L = gH, dmgH, chgH) complexes under photochemical conditions forms a mixture of products within 5 min. The equilibration/decomposition of ArCH2Co(L)(dpgH)Py to the corresponding ArCH2Co(L)(2)Py and ArCH2Co(dpgH)(2)Py complexes and molecular oxygen insertion starts immediately and simultaneously. The ratio of these products changes with time, and finally ArCH2(O-2)Co(L)(dpgH)Py and ArCH2(O-2)Co(dpgH)(2)Py are the major products formed. The spectral data are interrelated, and a good correlation is found between Delta delta(1)(H)(Py-alpha) and delta(13C)(C=N-gH) or delta(13C)(C=N-dpgH), indicating ring current throughout the metallabicycle. The CV data show that the dioxy complex is easier to reduce than the parent complex. The molecular structure of 4-Cl-C6H4CH2Co(dpgH)(gH)Py has been reported.
Organocobaloximes with mixed dioxime equatorial ligands: a convenient one-pot synthesis. X-ray crystal structures of BnCoIII(dmgH)(dpgH)Py and BnCOIII(chgH)(dpgH)py
A simple and general route to the synthesis of organocobaloxime with mixed dioxime ligands, RCo(dmgH)(dpgH)Py and RCo(chgH)(dpgH)Py, has been described. The C-13-NMR chemical shifts have been analysed to see whether one dioxime wing has any effect on the other dioxime wing. The first crystal structure of an organocobaloxime with mixed dioxime ligand in the same complex, BnCo(dmgH)(dpgH)Py and BnCo(chgH)(dpgH)Py, is reported. (C) 2001 Published by Elsevier Science B.V.