Much of the progress in transition - metal cluster chemistry has been made since the mid-1960's. This is in part due to a prospect that discrete cluster molecules may mimic metal surfaces in the processes of chemisorption and catalysis. Mixed - metal cluster compounds are currently under intense scrutiny as they have a number of advantages over their homonuclear couterparts.
The reaction of $Os_3(CO)_{10}(NCMe)_2$ with $Cp(CO)_2$M(CTol) provides a dark red crystalline product, which is formulated as $CpMOs_3(CO)_{11}$ $(\mu_3-CTol)$[1(M=Mo), 5(M=W)]. Initial decarbonylation of 1 and 5 with $Me_3NO$/MeCN followed by reaction with dihydrogen (70psig) at 25℃ gives a dihydride complex, $CpMOs_3(CO)_{10}(\mu_3-CTol)$ $(\mu-H)_2$[2(M-Mo), 6(M=W) of metal atoms with an $WOs_2$ edge capped by the triplybridging CTol ligand. The reaction of $CpMOs_3(CO)_{10}(\mu_3-CTol)(\mu-H)_2$ with $PPh_3$ occured simple addition, and compounds 2 and 6 undergoes a thermal reaction with dihydrogen to yield $CpMOs_3(CO)_9(\mu-O)(\mu_3-CTol)H$ [4(M=Mo), 8(M=W)which has a closo tetrahedral cluster framework.
Compounds 1∼11 have been isolated as crystalline solids and characterized by spectroscopic (infrared, $^1H$ and $^{13}C$ NMR) data. The actual structures of 2,8 and 9 have been by single crystal X - ray diffraction studies.
