Tungsten nitrido amido guanidinato complexes of the type WN(NR2)[(NR')2C(NR2)]2 (R = Me, Et; R' = i Pr, Cy) were synthesized as precursors for aerosol-assisted chemical vapor deposition (AACVD) of WNxCy thin films. The reaction of tungsten nitrido amido complexes of the type WN(NR2)3 (R = Me, Et) with two equivalents of a carbodiimide R'N=C=NR' (R' = i Pr, Cy) resulted in two insertions of a carbodiimide into W-N(amido) bonds, affording bis(guanidinato) amido nitrido tungsten complexes. These compounds were characterized by 14N NMR, indicating distinctive chemical shifts for each type of N-bound ligand. Crystallographic structure determination of WN(NMe2)[(N i Pr)2C(NMe2)]2 showed the guanidinato ligands to be non-equivalent. The complex WN(NMe2)[(N i Pr)2C(NMe2)]2 was demonstrated to serve as a precursor for AACVD of WNxCy thin films, resulting in featureless, X-ray amorphous thin films for growth temperatures 200 - 400 °C.
Keywords: chemical vapor deposition; inorganic synthesis; precursor design; thin film; tungsten.