1,2,3,4,7,7-Hexafluorobicyclo[2.2.1]heptadiene ( 1) and 2,3-bis(trimethyltin)-1,4,5,6,7,7-hexafluorobicyclo[2.2.1]hepta-2,5-diene ( 2) react with [M(Ph 3P) 4] (M = Pt, Pd) to afford air-stable adducts. 2,3-Dichloro-1,4,5,6,7,7-hexafluorobicyclo[2.2.1]hepta-2,5-diene ( 3) gives only [PtCl 2(PPh 3) 2] with [Pt(Ph 3P) 4], but a low yield of an adduct was obtained with [Pd(PPh 3) 4]. The diene 1 also reacts with Fe(CO) 5 to form the complex [(C 7H 2F 6)Fe(CO) 4], and with [Rh(C 2H 4) 2(acac)] to give [(C 7H 2F 6)Rh(acac)] in which the diene acts as a bidentate ligand. Similar products could not be isolated from the reactions of 2 and 3. A stable adduct, believed to be [{C 7F 6(SnMe 3) 2}Rh(CO) 2(μ-Cl) 2Rh(CO) 2] has been isolated from the reaction between 2 and [Rh(CO) 2Cl] 2. This adduct reacts with PPh 3 to give the bridge-cleavage product [{C 7F 6(SnMe 3) 2}RhCl(CO)(PPh 3) 2]. Reaction of 1 with [Rh(CO) 2Cl] 2 gives an unstable adduct which could not be isolated, and 2 does not react at room temperature. The chloro derivative 3 reacts with [PdCl 2(PhCN) 2] to give the adduct [(C 7F 6Cl 2)PdCl(PhCN)], but 1 and 2 do not react under similar conditions. Stable substitution products [(C 7F 6R 2)M] (R = H, M = Fe(CO) 2(η-C 5H 5); R = SnMe 3, M = Fe(CO) 2(η-C 5H 5), Mn(CO) 5, Ir(CO) 2(PPh 3) 2, Rh(CO) 2(PPh 3) 2; R = Cl, M = Ir(CO) 2(PPh 3) 2, Rh(CO) 2(PPh 3) 2) have been isolated from the reactions of the dienes with carbonylmetal anions. Insertion of the CHCH bond occurs when 1 is heated with [MnMe(CO) 5] to give [{C 7F 6H 2C( O)Me}M n(CO) 4], and this, on reaction with either PPh 3 or [Pt(PPh 3) 4], gives [(C 7F 6H 2COMe)Mn(CO) 4PPh 3].