Polyhydride Complexes with CO versus Halide Ligands

POLYHYDRIDE COMPLEXES WITH CO VERSUS HALIDE LIGANDS 

Many varieties of H2 complexes with halide ligands are known where the strong influence of the halide has been noted and extensively studied theoreti- 

INTERACTION OF A COORDINATED (T BOND WITH A CIS LIGAND THE CIS EFFECT IN HYDRIDE-DIHYDROGEN COMPLEXES 

Heterolytic cleavage of H2 can involve transfer of H+ to a metal bound ligand cis to a transient H2 ligand, while H binds to M.169 Although the heterolytic 

Both experimentally and calculationally, complexes that contain a hydride cis to a H2 ligand often show structural distortions and orientations of r/2-H2 indicative 

Although halides, particularly Cl, are strong r-electron-with-drawing ligands, which confers cation-like character, their n-donating ability 

The situation can be quite conplex however, as illustrated by Hj addition to OsCl H4 (P Pr3)2 (see Table 4.11). H2 coordination is weakaied when Cl replaces hydride ligands, as can be seen by the trend in — AG° of binding. This seems counterintuitive because more BD to is expected for n = 2, where the H2 is stretched ( hh A), than for n = 1. However, the degree of Q M bonding 

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