Disclosed are Group 6 film forming compositions comprising Group 6 transition metal-containing precursors selected from the group consisting of: M(═O)2(OR)2  Formula I, M(═O)(NR2)4  Formula II, M(═O)2(NR2)2  Formula III, M(═NR)2(OR)2  Formula IV, and M(═O)(OR)4  Formula V, wherein M is Mo or W and each R is independently H, a C1 to C6 alkyl group, or SiR′3, wherein R′ is H or a C1 to C6 alkyl group. Also disclosed are methods of synthesizing and using the disclosed compositions to deposit Group 6 transition metal-containing films on substrates via vapor deposition processes.