Complexes of Nb(V) and Ta(V) with 8-quinolinol and tropolone

Abstract The reactions of niobium or tantalum pentaalkoxides with 8-quinolinol (oxH) yielded the derivatives of the type M(OR) 5−n (ox) n (M = Nb or Ta; R = Pr i or Et; n = 1, 2 and 3). Niobium pentaethoxide with an excess of tropolone (tH) yielded Nb (OEt)t 4 . Some physical and chemical studies of these compounds are reported.