Structural models for [M(CO)(3)(H2O)(3)](+) (M = Tc, Re): fully aqueous synthesis of technetium and rhenium tricarbonyl complexes of tripodal oxygen donor ligands

The reaction of [M(H2O)(3)(CO)(3)](+) (M =Tc, Re) with Na[CpCo[PO(OR)(2)](3 )] (NaLOR; R = Me, Et) in water produced the compounds M(CO)(3)(L-OR), all of which were yellow solids, in yields varying from 55 to 89%. The two comp ounds M(CO)(3)(L-OEt) were structurally characterized by single crystal X-r ay crystallography. In both cases, the ligand L-OEt was bound to the metal center in a tridentate fashion utilizing an {OOO} donor set. The ligands L- OR can be used as models for facially coordinated triaqua groups owing to t heir position in the spectrochemical series. Therefore, these four compound s, M(CO)(3)(L-OR), can be considered structural models for [M(H2O)(3)(CO)(3 )](+) Crystal data for Tc(CO)(3)(L-OEt) are as follows: molecular formula C 20H35CoO12P3Tc, MW = 717.32, monoclinic, a = 11.5661(11) Angstrom, b = 18.6 71(2) Angstrom, c = 13.7852(13) Angstrom, beta = 92.770(2)degrees, V = 2973 .5(5) Angstrom (3), space group P2(1)/n, Z = 4, final R-1 = 0.0669, wR(2) = 0.1361. Crystal data for Re(CO)(3)(L-OEt) are as follows: molecular formul a C20H35CoO12P3Re. MW = 805.52. monoclinic, a = 11.5113(7) Angstrom, b = 18 .6022(12) Angstrom, c = 13.7397(8) Angstrom, beta = 92.7580(10)degrees, V = 2938.7(3) Angstrom (3) space group P2(1)/n, Z = 4, final R-1 = 0.0384, wR( 2) = 0.0760. (C) 2001 Elsevier Science B.V. All rights reserved.