Synthesis, X-Ray, and Electronic Structures of a New Nickel Dibromide Complex. Activity in the Regioselective Catalyzed Dimerization of Ethylene into 1-Butene

Reaction of the bis-(3,4)-dimethylphosphole-Xanthene 1b with [NiBr2(DME)] afforded a new nickel(II) dibromide
complex, 2. Both its color and its NMR behavior change with temperature and solvent due to changes in the spin
state of the complex. This led us to study the complex spin states using DFT calculations. Furthermore, the activity
of 2 in catalyzed ethylene dimerization was studied, revealing both high activity and selectivity toward the production
of 1-butene.