Mixed complexes of N,N'-ethylenebis(salicylideneiminato)uranium(IV)

Some mixed N,N′-ethylenebis(salicylideneiminato), salen, complexes of uranium(IV) of formula U(salen)X2(X = Cl, acetylacetonato, dipivaloylmethanato, N-methylsalicylideneiminato, dibenzoylmethanato) are reported. It is shown that U(salen)2 and UCl4 undergo a ligand redistribution reaction in tetrahydrofuran (THF) leading to U(salen)Cl2,2THF. Chemical and mass spectrometric data are presented supporting the monomeric structure of the complexes of formula U(salen)(chelate)2. Evidence is presented suggesting the transitory formation of the adduct U(salen)2,UCl4 in the course of the redistribution reaction leading to U(salen)Cl2.