The thermal decomposition pathways of the tungsten dimethylhydrazido complexes Cl-4(RCN)W(NNMe2) (1a: R= CH3; 1b: R=Ph), precursors for single source deposition of WNxCy, were investigated using a combination of experiments and calculations. Raman scattering studies were performed in an impinging-jet, up-flow, aerosol-assisted CVD reactor to identify reaction intermediates. Density Functional Theory calculations (B3LYP/LanL2DZ) were used to estimate Raman active frequencies and explore the reaction surface. Dimethylamine and methylmethyleneimine, products from N-N cleavage of the hydrazido ligand, were observed under deposition conditions and identified by comparison with previously reported Raman shifts and calculated frequencies. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.002206jes] All rights reserved.