Vanadocenes (VCp2 and its derivatives) have certain volatility and have been proposed as potential precursors for CVD processes. Several publications are present, however, only few data are available concerning the composition of the obtained films.
Vanadocene ( Vanadium bis(cyclopentadienyl) ) VCp2 (Cp = C5H5) is synthesized by methathesis from vanadium dichloride and sodium cyclopentadienyl:
VCl2 + 2 Na(C5H5) → V(h5-C5H5)2 + 2 NaCl
Alternatively, it can be obtained by reduction of vanadium bis(cyclopentadienyl) dichloride by metallic sodium:
(h5-C5H5)2VCl2 + 2 Na → V(h5-C5H5)2 + 2 NaCl
Vanadocene ( Vanadium bis(cyclopentadienyl) ) VCp2 (Cp = C5H5) was applied as an organometallic precursor for the low temperature growth process of uniform vanadium carbide
(VC) layers at temperatures at 200°C, 400°C and 650°C. 4 μm average thickness VC coating was obtained at 650 °C (as determined by cross section profile and phase identification methods). The diffusion behavior of HT9/VC/Ce after annealing
at 660 °C for 100 h was compared to that of the uncoated HT9/Ce; a substantial decrease of inter-diffusion zone was achieved by using VC coating (demonstrating that VC coatings may be useful as diffusion barrier against Ce and possibly other lanthanides).[i]
[i] Sh. Huang, W.-Y. Lo, Y. Yang, Fusion Eng. Design, 2017, Vol. 125, p.556-561, « Vanadium carbide by MOCVD for mitigating the fuel cladding chemical interaction » , https://doi.org/10.1016/j.fusengdes.2017.04.118 , https://www.sciencedirect.com/science/article/pii/S0920379617305215