Linkage block metal complexes

In addition to covalent coupling, the non-covalent linkage of different blocks, either by metal-Hgand complex formation or by selective hydrogen bonding, appeared as a recent tendency in block copolymer synthesis. 

Hydrocarbons containing main-group elements such as boron, silicon, and tin are ubiquitous building blocks for the synthesis of complex molecules. Transition-metal-catalyzed cross-coupling reactions of carbon-main-group element linkages as well as their transformation into more valuable functional groups are powerful tools of modem synthetic chemistiy. 

The purpose of this chapter is to survey and to analyze, in a necessarily brief and selective manner, actinide organometallic chemistry involving metal-carbon, metal-hydrogen, and metal-metal a bonds. Such linkages are fundamental building blocks of modem organometallic chemistry and catalysis. The nature of actinide complexes based upon coordination to multihapto organic n-electron systems was surveyed in Chapter 22. 

The first hydride complex investigated by the neutron diffraction technique was K2[ReH9] containing the terminal M—H linkage. Many examples of complexes containing the terminal hydride ligands are now known for virtually all d-block transition elements. Binary transition-metal hydrides are rather few and the majority are stabilized by carbonyl, phosphine, or other ancillary ligands. 

---