SYNTHESIS OF NITROSYL RHENIUM(I) COMPLEXES BEARING BIDENTATE LIGANDS

The reaction of [ReCl(mu-Cl)(COE)(CO)(NO)](2) (2) (obtained from [ReCl (mu-Cl)(CO)(2)(NO)] and cyclooctene (COE)) with 2,2'-bipyridine and 4, 4'-dimethyl-2,2'-bipyridine leads to ReCl2(CO)L(NO) complexes (L = 2,2 '-bipyridine (3), 4,4'-dimethyl-2,2'-bipyridine (4)) with trans chlori de substituents. The reaction of [ReCl(mu-Cl)(CO)(2)(NO)](2) (1) with THF produces racemic ReCl2(CO)(2)(THF)(NO) (5). The Re-THF bond in 5 i s labile enough to provide a primary coordination site for a bidentate ligand attack. The reaction of 2 with bpy proceeds with regioselectiv e Re-Cl cleavage trans to the CO ligand and affords the ionic [ReCl(CO )(2)(bpy)(NO)][ReCl3(CO)(2)(NO)] complex 6 or, when a stoichiometric a mount of NaBF4 is present, [ReCl(CO)(2)(bpy)(NO)][BF4] (7). The reacti on of 2 with 1,2-bis(diphenylphosphino)methane (dppm) gives cis,trans- [ReCl2(eta(1)-dppm)(2)(CO)(NO)] (8) while the transformation with 1,2- bis(diphenylphosphino)ethene (dppee), and NaBF4, yields an ionic [ReCl (NO)(dppee)(2)][BF4] compound 9. The reaction of racemic trans-1,2-bis (dimethylphosphino)cyclopentane (dmpc) with 5 proceeds with loss of th e THF molecule and of one CO group, affording a diastereomeric mixture of ReCl2(CO)(dmpc)(NO) (10). The compounds 2, 4, 5, 6, 8, 9 and 10 we re characterized by X-ray diffraction studies. Crystal data: 2, monocl inic, space group P2(1)/c, a = 9.471(5), b = 10.646(6), c = 12.599(7) Angstrom, beta = 99.78(2)degrees, V = 1251.8(12) Angstrom(3), Z = 2; 4 , monoclinic, space group C-2/m, a = 13.472(4), b = 21.717(7), c = 6.4 91(2) Angstrom, beta = 105.33(2)degrees, V = 1831.7(9) Angstrom(3), Z = 4; 5, monoclinic, space group P2(1)/n, a = 6.114(3), b = 18.443(12), c = 9.954(5) Angstrom, beta = 96.09(2)degrees, V = 1116.2(10) Angstro m(3), Z = 4; 6, triclinic, space group P (1) over bar, a = 8.894(2), b = 10.376(2), c = 14.660(4) Angstrom, alpha = 97.62(2)degrees, beta = 97.46(2)degrees, gamma = 102.67(2)degrees, V = 1290.4(6) Angstrom(3), Z = 2; 8, monoclinic, space group P2(1)/n, a = 10.029(3), b = 30.364(9 ), c = 16.487(3) Angstrom, beta = 98.10(2)degrees, V = 4971(2) Angstro m(3), Z = 4; 9, trigonal, space group P (3) over bar, a = 20.648(7), c = 11.326(4) Angstrom, V = 4182(3) Angstrom(3), Z = 4; 10, tetragonal, space group Fdd2, a = 14.265(3), b = 50.190(10), c = 9.217(2) Angstro m, V = 6599(2) Angstrom(3), Z = 16.