On the nature of Ni⋯Ni interaction in a model dimeric Ni complex

Abstract

A new dinuclear complex (NiC₅H₄SiMe₂CHCH₂)₂ (2) was prepared by reacting nickelocene derivative [(C₅H₄SiMe₂CHCH₂)₂Ni] (1) with methyllithium (MeLi). Good quality crystals were subjected to a high-resolution X-ray measurement. Subsequent multipole refinement yielded accurate description of electron density distribution. Detailed inspection of experimental electron density in Ni⋯Ni contact revealed that the nickel atoms are bonded and significant deformation of the metal valence shell is related to different populations of the d-orbitals. The existence of the Ni⋯Ni bond path explains the lack of unpaired electrons in the complex due to a possible exchange channel.