Gaseous ligand examples

Another manifestation of ligand field stabilization energy can be seen from the heats of hydration of the transition metal ions. For example, the hydration of a gaseous ion results in the formation of an aqua complex as represented by the equation... 

Mononuclear Ru(N2)(P Pri)(N2Me2S2)] exhibits no peculiarities with respect to distances, angles, mode of binding the N2 ligand, and so on, when compared with other regular N2 complexes. For example, its v(N2) frequency at 2113 cm-1 (KBr) reflects a normal N2 activation with respect to the v(N2) frequency of gaseous N2 (2331 cm-1). 

The nitrogen-donor complexes of gold(lll) are usually formed by the displacement of chloride in H[AuCLi] by nitrogen-donor ligands. The complex [Au(NH3)4](N03)3, for example, is obtained by bubbling gaseous ammonia into an aqueous solution of H[AuCL(] and ammoninm nitrate. 

The olefin metathesis reaction proceeds by a series of [2 + 2] cycloadditions and retro-cycloadditions. No change in metal oxidation state occurs in the course of the reaction. The reaction sets up an equilibrium between all the possible alkenes, but it is possible to drive the equilibrium in one direction or the other, for example, by removal of gaseous ethylene. The two Grubbs catalysts undergo dissociation of a Cy3P ligand before the catalytic cycle begins so that coordination of the alkene to the metal may precede each [2 + 2] cycloaddition. 

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