Interstitial and high-coordinate hydride complexes

Most interstitial metal hydrides have variable composition, for example, PdHx with x 1. The hydrogen atoms are assumed to have lost their electrons to the d 

Storage medium Hydrogen percent by weight Hydrogen density (kg dm ) 

A striking property of many interstitial metal hydrides is the high rate of hydrogen diffusion through the solid at slightly elevated temperatures. This mobility is utilized in the ultra-purification of H2 by diffusion through a palladium-silver alloy tube. 

In the majority of its metal complexes, the hydride ligand normally functions in the /x1 (terminal), /tx2(edge-bridging), and /x3 (triangular face-capping) modes. Research efforts in recent years have led to the syntheses of an increasing number of high-coordinate (/u4, /u5, and /x6) hydride complexes. 

P—x isotherms for the FeTiH alloy. The upper curve corresponds to the equilibrium pressure as hydrogen is added stepwise to the alloy the lower curve corresponds to the equilibrium pressure as hydrogen is removed stepwise from the hydride. 

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