METAL DONOR-]METAL ACCEPTOR COMPLEXES - FE(CO)42- HFE(CO)4-, AND TRANS-HFE(CO)3P(OME)3- AS ANIONIC LIGANDS TO CR(CO)50, W(CO)50
Academic Article
Overview
Identity
Additional Document Info
View All
Overview
abstract
A series of heterobimetallic carbonyl anions have been synthesized and structurally characterized as their bis-(triphenylphosphine)iminium salts. Compound 1, crystallizes in space group P1 (Z = 2): a = 14.099 (5) A, b = 11.601 (5) A, c = 14.148 (5) A, a = 95.53 (3),= 118.23 (3), = 92.39 (3), 2026 (3) A3; Rw = 0.061 for 3637 unique reflections measured >3(I). Compound 2, PPN+HFeW(CO)8P(OMe)3- crystallizes in space group P21/N (Z = 4): a = 12.200 (2) A, b = 12.461 (2) c =32.032 (4) A, a = 90.00, = 96.40 (1), y = 90.00, V = 4838 (2) A3; Rw = 0.069 for 1769 unique reflections measured >3(I). Compound 3, PPN+HFeCr(CO)9-, crystallizes in space group (Z =2): a = 11.717 (2) A, b = 14.095 (3) A, c = 14.283 (2) a = 92.18 (2), = 117.51 (1), y = 95.78 (2), V = 2072 (1) A3; = 0.053 for 1321 unique reflections measured >3(I). Finally, compound 4, (PPN+)2FeCr(CO)92-, crystallizes in space group PI (Z = 2): a = 13.882 (2) A, b = 22.825 (4) A, c = 13.067 (2) A, a =96.07 (1), = 117.57 (1), y = 87.27 (1), V = 3650 (2) A3; Rw =0.060 for 3905 unique reflections measured >3(I). The structural features common to all complexes are all terminal CO groups and a Fe-M (M = Cr, W) bond. This bond is viewed as a Fe: M donor-acceptor complex in which Fe- donates to an electrophilic group 6 metal pentacarbonyl moiety. In the series, the Fe-M bond distance ranges from 2.941 (2) A for 4 to 2.997 (2) A for 1. The small bond distance change of 0.015 A on going from the dianion 4 to the protonated form 3 and the appropriate angle deformations as well as the identical M-CO arrangement of the Ph3PAuFeW(CO)9- anion suggest the hydride to be terminal and located solely on Fe. Various spectral (IR, 13C NMR) and chemical characterizations are also reported. 1986, American Chemical Society. All rights reserved.
