Synthesis and Reactivity of Ln-H Bonds

One of the most recent and rapidly developing areas of organolantha-nide chemistry involves species containing Ln—H bonds. This area is so new that the information in this section is not presented in other review articles (5-7). Nevertheless, the area has developed so quickly that not only are synthetic and structural results available, but information on reactivity is also known. 

As described in Section IV,B, hydrogenolysis of lanthanide—alkyl bonds in (CsH4R)2LnR complexes provided a synthetic route to organolanthanide hydrides [Eqs. (10)-(12)]. The structure of the first ciystallographi- 

The dimeric hydrides, [(C5H4R)2Ln( i-H)(thf)]2, could be obtained from (C5H4R)2Ln(r-C4H9)(thf) not only by hydrogenolysis but also by /3-hydrogen elimination [Eq. (16)]. 

If the (C5H5)2Ln(r-C4H9)(thf) complexes jS-hydrogen eliminate in the presence of LiCl, a new type of organolanthanide complex is formed [Eq. (17), Cp = C5H5, Ln = Er,Y] (54). Since LiCl is a by-product in the 

The lutetium complex can also be obtained by hydrogenolysis in the presence of lithium reagents starting from (CsHs)2Lu(r-C4H9)(thf). The origio of the UH incorporated into this trimer was more difficult to explain than the origin of LiCl in Eq. (17). Perhaps related to this is the fact that the yield in Eq. (18) was 12%. 

---