As we know, coordinatively unsaturated complexes can catalyze hydrogen generation via an unstable hydride intermediate. In this paper, we report an electrocatalyst based on a water soluble coordinatively saturated complex, [(phen)(2)Co(CN)(2)]center dot NO3 1 that is formed by the reaction of 1,10-phenanthroline (phen), Co(NO3)(2)center dot 6H(2)O and tetracyanoethylene (TCNE). Its structure has been characterized by physics-chemical and spectroscopic methods. Complex 1 can electrocatalyze hydrogen evolution both from acetic acid and aqueous buffer. (C) 2016 Elsevier B.V. All rights reserved.