a): (CO)4 ML or (b): M2 [??-??:??4 -C4 ](CO)6 ; wherein L is a two-electron donor ligand and each R is H, halo,...http://www.google.com/patents/US5372849?utm_source=gb-gplus-sharePatent US5372849 - Using a volatile ligand-containing metal tetracarbonyl complex ; decomposing by heat at low temperature or by radiationAdvanced Patent SearchPublication numberUS5372849 APublication typeGrantApplication