Chain Compounds of Rhodium

The self-association of planar d transition-metal complexes with the formation of weak metal-metal bonds is prominently featured for Rh. Discrete oligomers to infinite stacks have been isolated in the solid state. As discussed in the following sections, the stability of these ID Rh chain molecules has been attributed to weak metal-metal interactions. Vacancy in the Rh d-band results mixed-valent chain compound of rhodium. The ligand-ligand interactions have been invoked to rationalize the stability of chain compounds as well. 

Cl2 (3.287(2) A) have been reported. The values in parenthesis are the corresponding Rh Rh separations. 

Monomeric, dimeric and trimeric Rh compounds are distinguished by their UV-Vis spectra. Yellow crystals of [(C6HnNC)4Rh ](BPh4), dispersed in 

Highly conjugated molecules offer prospect in the formation of a ID stack through n-n interactions. Cofacial linear oligomers of rhodium have been 

The mixed-valent, square-planar cation [Rh (CO)2(CH3CN)2] was reported to form one-dimensional stack in the solid state. The chain is composed of the repeat unit [ Rh2 (02CCF3)2(C0)4 Rh2 °(02CCF3)4 Rh (02CCF3)2(C0)4 ] , in which an Rh ,Rh unit is connected with two dimeric Rh, Rh units. A linear chain composed of dirhodium units is not limited to acetonitriles and carbonyls. Metal chains of the type [ Rh2(OAc)2(LL)2 (BF4)] (LL = 1,10-phenanthroline 2,2 -bipyridyl) have been prepared by one-electron reduction of the corresponding dirhodium(II,II) precursors [Rh2(OAc)2 (LL)2] in aqueous ethanol. For the phen compound, three different Rh-Rh separations are noted in the Rh chain. The carboxylate bridged Rh-Rh distance is 2.652 A the unsupported interdimer Rh-Rh distance is 2.739 A and the resultant tetranuclear fragments are linked into an infinite chain by Rh-Rh 

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