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Synthesis and characterization of cyclometallated complexes of palladium(II) and manganese(I) with bidentate Schiff bases

1996; Elsevier BV; Volume: 506; Issue: 1-2 Linguagem: Inglês

10.1016/0022-328x(95)05691-h

1872-8561

J.M. Vila, M. Gayoso, Ma.Theresa Pereira, M. López-Torres, Jesús J. Fernández, Alberto Fernández, Juan M. Ortigueira,

Organometallic Complex Synthesis and Catalysis

Treatment of N,N-isophthalylidenebis(cyclohexylamine), 1,3-(CyNCH)2C6H4 (L2) (Cy = cyclohexyl) with palladium(II) acetate in glacial acetic acid gave after column chromatography the monocyclometallated dimer complex [{Pd[3-(CHO)C6H3C(H)NCy](O2CMe)}2] (1) with a free formyl group on each phenyl ring, and a mixture of 1 with the doubly cyclometallated complex [Pd{3-(CyNCH)C6H3C(H)NCy}(O2CMe)] (2). Treatment of 1 with cyclohecylamine gave the corresponding dimer complex [{Pd[3-(CyNCH)C6H3C(H)NCy]O2CMe)}2] (17 with an uncoordinated CN group on each phenyl ring. Treatment of 1 and 2 with aqueous NaX gave the dimer complexes [{Pd[3-(CHO)C6H3C(H)NCy](X)}2] (3: X = Cl; 4 X = Br; 5: X = I) and a mixture of 3, 4 or 5 with the doubly cyclometallated complex [{Pd[3-(CyNCH)C6H3C(H)NCy}(X)] (6: X = Cl; 7: X = Br; 8: X = I), respectively. The dicyclometallated iodo complex 8 was isolated pure. Treatment of 3, 4 or 5 with cyclohexylamine in a 1 : 2 or 1 : 4 molar ratio gave the cyclometallated complexes [{Pd[3-(CHO)C6H3C(H)NCy}(X)(NH2Cy)] (9: X = Cl; 10: X = Br; 11: X = I) and [{Pd[3-(CyNCH)C6H3C(H)NCy}(X)(NH2Cy)] (12: X = Cl; 13: X = Br; 14: X = I), respectively; the last three compounds each contain an uncoordinated C  N group. The corresponding bromo and iodo analogues were made similarly. Treatment of 3, 4 or 5 with thallium cyclopentadienyl or thallium acetylacetonate gave the mononuclear complexes [{Pd[3-(CHO)C6H3C(H)NCy}(C5H5)] (15) and [{Pd[3-(CHO)C6H3C(H)NCy}(H3CCOCHCOCH3)] (16), respectively. Treatment of L2 with MnMe(CO)5 in a 1 : 1 molar ratio gave the monocyclometallated complex [(OC)4Mn{3-(CHO)C6H3C(H)NCy}] (18) by cleavage of one CN bond, whereas treatment of L2 with MnMe(CO)5 in a 1 : 1.2 molar ratio produced a mixture of the doubly cyclometallated complex 19 and the monocyclometallated complex 20 without cleavage of the C  N bond. Treatment of N,N-terephthalylidenebis(cyclohexylamine), 1,4-(CyNCH)2C6H4 (L1) (Cy = cyclohexyl), with MnMe(CO)5 in a 1 : 1.2 molar ratio gave a mixture of the monocyclometallated compound [(OC)4Mn{4-(CHO)C6H3C(H)NCy}] (22) and the monocyclometallated compound [(OC)4Mn{4-(CyNCH)C6H3C(H)NCy}] (23); compound 22 was isolated in a pure state.