Structure studies continued tungsten with

His proposal involved a metal carbene and a metallocyclobutane intermediate and was the first proposed mechanism consistent with all experimental observations to date. Later, Grubbs and coworkers performed spectroscopic studies on reaction intermediates and confirmed the presence of the proposed metal carbene. These results, along with the isolation of various metal alkyli-dene complexes from reaction mixtures eventually led to the development of well-defined metal carbene-containing catalysts of tungsten and molybdenum [23-25] (Fig. 2). After decades of research on olefin metathesis polymerization, polymer chemists started to use these well-defined catalysts to create novel polymer structures, while the application of metathesis in small molecule chemistry was just beginning. These advances in the understanding of metathesis continued, but low catalyst stability greatly hindered extensive use of the reaction. 

To study the effect of the other electrolysis parameters on the properties and structure of W2C coatings, we chose the optimal melt NaCl-LiCl - 0.5 wt%, Na2W04 -0.4wt% Na2C03. Continuous deposits were obtained at 1073-1173 K. At lower temperatures, tungsten oxides are deposited together with metal and carbide. Well adhered, uniform, and nonporous coatings were obtained at a cathodic current density of 2-15 A/dm with a deposition rate from 2 to 20 pm/h (Figure 4.8.1). 

---