Specific Behavior of the Electrochemically Generated Organonickel Sigma-Complex [NiBr(Tcpp)(bpy)], where Tcpp is 2,4,6-Tricyclopentylphenyl, bpy is 2,2'-Bipyridine.

A novel organonickel sigma-complex [NiBr(Tcpp)(bpy)], where Tcpp is 2,4,6-tricyclopentylphenyl, bpy is 2,2'-bipyridine has been generated in solution by electrochemical macroscale synthesis. The monitoring of the macroscale electrosynthesis and also the cyclic voltammetric measurements have shown that the organonickel sigma-complex is formed at the electrolysis but, in contrast to its analogues with ortho-substituted aromatic fragments, is unstable and decomposes to the homo-coupling product, namely, the earlier unknown sterically hindered biaryl derivative 2,2',4,4',6,6'-hexacyclopentyl-1,1'-biphenyl, the molecular and crystal structure of which are described by NMR spectroscopy and X-ray diffraction techniques. [ABSTRACT FROM AUTHOR]