The olefinic phosphane P(C 7 H 7 ) 3 (5) behaves as a tetradentate tripod ligand in [RhCl{P(g 2 -C 7 H 7 ) 3 }] (6), using all 3 cyclohepta-2,4,6-trienyl substituents as g 2 -coordinating side-arms. Nucleophilic displacement of the one-electron chloro ligand by halides or pseudohalides to give [RhX{P(g 2 -C 7 H 7 ) 3 }] (X = Br (7 a), I (7 b), N 3 (7 c), NCO (7 d)) leaves the basket-like framework [Rh{P(g 2 -C 7 H 7 ) 3 }] intact. Reactions of 6 with three-electron ligands result in decomplexation of one cyclohepta-2,4,6-trienyl ring and formation of [Rh(L 3 ){P(C 7 H 7 )(g 2 -C 7 H 7 ) 2 }] (L 3 = acetylacetonate (8), 2carboethoxy cyclopentanonate (8 a)), reactions of 6 with five-electron ligands such as g 5 -C 5 H 5 cause decomplexation of two olefinic side-arms to give [Rh(L 5 ){P(C 7 H 7 ) 2 (g 2 -C 7 H 7 )}] (L 5 = g 5 -C 5 H 5 (Cp) (9), g 5 -C 5 H 4 t Bu (9 a)). The last remaining chelate ring in 9 is opened by pressure-carbonylation to give the adduct [Rh(Cp)(CO){P(C 7 H 7 ) 3 }] (10) or by oxidative addition of halogens to form [Rh(Cp)X 2 {P(C 7 H 7 ) 3 }] (X = Br, I).
The full set of 1 H, 13 C, 31 P, and 103 Rh NMR data is given for the prototype complexes 7 a, 8, 9, and 10, and the molecular geometries of the [Rh{P(C 7 H 7 ) 3 }] fragments are compared on the basis of the X-ray structural determinations of 6, 8, 8 a, 9, 9 a, and 10. The chemical shifts d( 31 P) provide a reliable parameter for the prediction of the molecular structures of the rhodium complexes in solution.