88904-60-3Relevant academic research and scientific papers
Reactivity of bridging phosphido ligands in WOs binuclear complexes. Crystal and molecular structure of (CO)5W(μ-PPh2)Os(H)(CO)2(PMePh 2)(PPh2H)
Rosenberg, Steven,Geoffroy, Gregory L.,Rheingold, Arnold L.
, p. 1184 - 1189 (2008/10/08)
The binuclear complex (CO)5W(μ-PPh2)Os(H)(CO)2(PMePh 2)(PPh2H), 3, is obtained from protonation of the formyl compound Li[(CO)4W(μ-PPh2)2Os(CHO)(CO) 2(PMePh2)]. Complex 3 has been characterized by a complete single-crystal X-ray diffraction study. It crystallizes in the space group C2/c with a = 35.172 (9) A?, b = 11.045 (3) A?, c = 25.275 (6) A?, β = 105.89 (2)°, V = 9444 (3) A?3, and Z = 8. The structure has been refined for the 5365 reflections with Fo ≥ 3σ(Fo) to RF = 0.036 and RwF = 0.041. The two nonbonded metal atoms are bridged by the μ-PPh2 ligand with the W further coordinated by five CO's and the Os by two CO's, the hydride, PPh2H, and PMePh2 ligands. Both the Os hydride and the hydrogen on phosphorus were located and refined. The W-Pμ-Os angle of 116.2 (1)° is the largest yet reported for this structural unit and illustrates the tremendous flexibility of this bridging ligand. Thermolysis of 3 leads to CO and H2 loss with formation of (CO)4W(μ-PPh2)2Os(CO)2(PMePh 2), 4, which involves formation of a second phosphido bridge. A second phosphido bridge also forms upon reaction of 3 with MeLi to give Li[(CO)4W(μ-PPh2)2Os(H)(C) 2(PMePh2)], 5, after loss of CO. If MeI is added immediately after addition of MeLi, the product is instead the monophosphido-bridged complex (CO)5W(μ-PPh2)Os(H)(CO)2(PMePh 2)2 6, formed as a mixture of two isomers. Protonation of 5 leads to the bridge cleavage product (CO)5W(μ-PPh2)Os(H)(CO)(PMePh2)(PPh 2H), 7, while methylation with [(CH3)3O]BF4 leads to formation of 4 Complex 4 is also obtained when solutions of 7 are heated to 55°C.
