Hydride complexes of transition metals

Many reducing cations in aqueous solutions can photoreduce water in low yields when irradiated in their charge transfer bands. Similarly, oxidizing cations can photo-oxidize water. Several hydride complexes of transition metals such as cobalt decompose on irradiation to yield molecular hydrogen... 

In coordination polymerization, monomer forms an adduct with a transition-metal complex, and further monomer is then successively inserted between metal and carbon. Termination occurs when the metal complex splits off from the polymer or the chain is broken intentionally by hydrogenolysis. Since the initiator is restored to its original form, the process is catalytic. The most important industrial processes are Ziegler-Natta polymerizations of a-olefins and employ solid catalysts. Most catalysts for coordination polymerization are hydride complexes of transition metals. An important example is the Shell Higher Olefin Process (SHOP) for homogeneous oligomerization of ethene with a complex nickel catalyst. The molecular-weight distribution is a Schulz-Flory distribution. The rate is first order in the catalyst metal. 

The hydrogen atoms in the vast majority of structures in the CSD are terminal, single-connected atoms and are represented via the atom property (nh) assigned to the relevant non-H atom. In those few cases where hydrogen is connected to more than one other atom, it is treated explicitly in the connectivity tables, i.e. it is regarded as a non-H atom. Deuterium is always treated in this way. The principal source of multi-connected H atoms arises in bridging hydride complexes of transition metals. This situation also occurs, but rarely, where the crystal structure indicates a... 

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