Interstitial hydrogen atom

Hydrido-clusters are usually prepared by protonation of anions. For example, the reaction of [Ru3(CO)i2] with aqueous KOH in THF solution results in cluster expansion to the octahedral dianion [Ru6(CO)ig] , protonation of which gives the monoanion [Ru6H(CO)i8] (in which the single H atom resides inside the Ru6 cavity), or the neutral dihydrido-cluster [H2Ru6(CO)ig] (in which the hydride ligands cap opposite faces of the octahedral metal cage), depending on the reaction conditions. 

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The insulator effect on metal-metal bonding for the interstitial hydrogen atom in an octahedral hole can be extended readily to other geometries. Table V shows that a similar effect is expected in a tetrahedral hole. 

Table II. Mean Distances 1 (A) Involving the Interstitial Hydrogen Atoms Determined from Neutron Diffraction Studies of Compounds 3 and 4...

The interstitial sublattice comprises interstitial hydrogen atoms and free internodes (vacancies V), whereas the metal lattice is composed of palladium atoms and vacancies V. The potential energy of the system can be presented as [195]... 

In the hexagonally close-packed Rh anions"" [Rh,j(CO)2 H5 j,]", where n = 2-4, protonation, instead of occurring at any specific Rh atoms or Rh—Rh bond, inserts an additional interstitial hydrogen atom ... 

T. F. Koetzle (1981). J. Am. Chem. Soc., 103, 1458-1466. An interstitial hydrogen atom in a hexanuclear metal cluster X-ray and neutron diffraction analysis of [(Ph3P)2N]"[HC06(CO),5r... 

Interstitial hydrogen atoms in c-C. Si. Ge. SiC. BN. BP, AlP. and GaN. In particular, the demonstration that hydrogen atoms form bridge-bond type configurations in covalent solids. 

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