Stabilization of Ni(I)(1,4,8,11‐tetraazacyclotetradecane) + in a Sol‐Gel Matrix: It's Plausible Use in Catalytic Processes

Monovalent nickel is used as a catalyst in a diversity of important chemical systems due to its properties as a strong reducing agent. However, monovalent nickel is unstable in homogeneous systems; its lifetime is very short, and therefore, its efficiency as a catalyst is quite limited. In this article, we demonstrate the catalytic capabilities of Ni(I)(1,4,8,11‐tetraazacyclotetradecane) + as a reducing and catalytic agent by its entrapment in the silica sol gel matrix. The EPR results indicate that the sol‐gel matrix plays two roles: it inhibits the common mechanism of Ni(I)L + decomposition in aqueous solutions, and it also facilitates its functionality as a heterogeneous catalyst, by stabilizing it for at least several hours. The activity of Ni(I)L + which is entrapped within the matrix, was studied by reducing 2,2‐Bis(bromomethyl)‐1,3‐Propanediol and I 3 − . The results indicate that Ni(I)L + /Ni(III)L−H 2+ acts as a good reducing agent. These results have important implications for a variety of essential catalytic reactions by shedding light on a new feature of sol‐gel matrices and their use as active species stabilizers.