Synthesis, structure and reactivity of bromo- and aquatricarbonylrhenium(I) phosphinite and phosphonite derivatives
作者:Rosa Carballo、Alfonso Castiñeiras、Soledad Garcı́a-Fontán、Pilar Losada-González、Ulrich Abram、Ezequiel M Vázquez-López
DOI:10.1016/s0277-5387(01)00820-8
日期:2001.8
[ReBr(CO)(5)] reacted with phosphinite or phosphonite ligands in benzene or toluene to yield fac-(1) or titer, trans-(2) complexes, ([ReBr(CO)(3)(L)(2)] L = PPh2(OMe), a; PPh2(OEt), b; PPh(OMe)(2), c; PPh(OEt)(2), d) characterized by elemental analysis, mass spectrometry, IR and NMR (H-1, C-13 and P-31) spectroscopies, and for complexes 1b, 2c and 2d, X-ray diffractometry was used. Complexes 2a-2d reacted with Ag[BF4] in wet acetone to form moderate yield of mer, trans-[Re(H2O)(CO)(3)(L)(2)][BF4] (3). Comparison of the spectra of compounds 3 with those of precursors 2 together with the diffractometric results for compounds 3a-3c, show that all the complexes have the same configuration around the rhenium atom. Crystals of compounds 3 consist of centrosymmetric dimers formed by hydrogen bonds between the water molecules and the BF4- anions. The lability of compounds 3 was explored by F-19 and P-31 NMR, and in the case of 3c the complex [Re(eta (1)-BF4)(CO)(3)PPh(OMe)(2)}(2)] (4c) was isolated from the mother liquor. Spectroscopic and diffractometric studies of 4c show monodentate coordination of the tetrafluorborato ligand to the rhenium atom. (C) 2001 Elsevier Science Ltd. All rights reserved.