Synthetic studies of hybrid chelate phosphine ligands and their metal complexes

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1. The oxidative-addition reactions of dichloromethane and cyclo-octasulfur with rhodium (I) complexes containing (2-aminoethyl) dimethylphosphine (edmp) or (2-aminoethyl) diphenylphosphine (edpp) have been examined. The reactions of [{RhCl (cod)}_2] (cod=cycloocta-1,5-diene) with edmp and with edpp in dichloromethane yield cationic adducts trans (Cl, C) cis (P,P') - [RhCl (CH_2Cl) (edmp)_2]^+ and trans (Cl, C) cis (P,P') - [RhCl (CH_2Cl) (edpp)_2]^+, the crystal structures of which being determined by X-ray analyzes. Addition of S_8 to [Rh (edmp)_2]^+ in methanol resulted in the formation of trans (N,N') - [Rh (S_4) (edmp)_2]^+ and a small amount of the S_5 complex. The analogous reaction with [Rh (edpp)_2]^+ gave a mixture of trans (P,N) - [Rh (S_4) (edpp)_2]^+ and trans (P,N) - [Rh (S_5) (edpp)_2]^+.2. Twelve new cobalt (III) complexes containing a tetradentate phosphine ligand of the type MeS (CH_2)_2PPh (CH_2)_nPPh (CH_2)_2SMe (n=2 L^1 or 3 L^2) were prepared. Their structures were assigned on the basis of electronic absorption and ^1H NMR spectra and the molecular structures of cisalpha- [CoCl_2 {rac (P) -L^1}] BF_4 and trans- [CoCl_2 {meso (P) - L^2}] BF_4 were determined by single-crystal X-ray diffraction. The last two complexes comprise a slightly distorted octahedron with the bond distances Co-P 2.210 (1), Co-S 2.254 (1) and Co-Cl 2.281 (1) and Co-P 2.227 (3), Co-S 2.327 (3) and Co-Cl 2.241 (3) *(all averages), respectively. The differences in Co-S and Co-Cl bond distances are atributed to the strong trans influence of the phosphino group.