The synthesis and molecular structure of the zero-valent platinum-mono-carbene-bis-alkene complexes [Pt0 (NHC)(dimethyl fumarate) 2](NHC= 1, 3-dimesityl-imidazol-2-ylidene (1a); 1, 3-dimesityl-dihydroimidazol-2-ylidene (2a); diphenyl-dihydroimidazol-2-ylidene (2b) are described. Two routes have been evaluated for the synthesis of 1a and 2a, involving reaction of a zero-valent platinum compound either with an isolated carbene ligand, or ...