Rhodium(I) complexes with κ P coordinated ω-phosphinofunctionalized alkyl phenyl sulfide, sulfoxide and sulfone ligands and their reactions with sodium bis(trimethylsilyl)amide and Ag[BF 4

Abstract

Reactions of ω-diphenylphosphinofunctionalized alkyl phenyl sulfides Ph 2P(CH 2) n SPh ( n = 1, 1a; 2, 2a; 3, 3a), sulfoxides Ph 2P(CH 2) n S(O)Ph ( n = 1, 1b; 2, 2b; 3, 3b) and sulfones Ph 2P(CH 2) n S(O) 2Ph ( n = 1, 1c; 2, 2c; 3, 3c) with dinuclear chlorido bridged rhodium(I) complexes [(RhL 2) 2(μ-Cl) 2] (L 2 = cycloocta-1.5-diene, cod, 4; bis(diphenylphosphino)ethane, dppe, 5) afforded mononuclear Rh(I) complexes of the type [RhCl{Ph 2P(CH 2) n S(O) x Ph-κ P}(cod)] 1 1 Here and in the following the letters a, b, and c in the numbering schemes refer to a sulfanyl ( x = 0), sulfinyl ( x = 1) and sulfonyl ( x = 2) functionality, respectively. ( n/ x = 1/0, 6a; 1/1, 6b; 1/2, 6c; 2/0, 8a; 2/1, 8b; 2/2, 8c; 3/0, 10a; 3/1, 10b; 3/2, 10c) and [RhCl{Ph 2P(CH 2) n S(O) x Ph-κ P}(dppe)] ( n/ x = 1/0, 7a; 1/1, 7b; 1/2, 7c; 2/0, 9a; 2/1, 9b; 2/2, 9c; 3/0, 11a; 3/1, 11b; 3/2, 11c) having the P^S(O) x ligands κ P coordinated. Addition of Ag[BF 4] to complexes 6– 11 in CH 2Cl 2 led with precipitation of AgCl to cationic rhodium complexes of the type [Rh{Ph 2P(CH 2) n S(O) x Ph-κ P,κ S/ O}L 2][BF 4] having bound the P^S(O) x ligands bidentately in a κ P,κ S ( 13a– 18a, 15b– 18b) or a κ P,κ O ( 13b, 14b, 13c– 18c) coordination mode. Unexpectedly, the addition of Ag[BF 4] to 6a in THF afforded the trinuclear cationic rhodium(I) complex [Rh 3(μ-Cl)(μ-Ph 2PCH 2SPh-κ P:κ S) 4][BF 4] 2·4THF ( 12·4THF) with a four-membered Rh 3Cl ring as basic framework. Addition of sodium bis(trimethylsilyl)amide to complexes 6– 11 led to a selective deprotonation of the carbon atom neighbored to the S(O) x group (α-C) yielding three different types of organorhodium complexes: a) Organorhodium intramolecular coordination compounds of the type [Rh{CH{S(O) x Ph}CH 2CH 2PPh 2-κ C,κ P}L 2] ( 22a– c, 23a– c), b) zwitterionic complexes [Rh{Ph 2PCHS(O) x Ph-κ P,κ S/ O}L 2] having κ P,κ S ( 21a, 21b) and κ P,κ O ( 20b/ c, 21c) coordinated anionic [Ph 2PCHS(O) x Ph] ligands, and c) the dinuclear rhodium(I) complex [{Rh{μ-CH(SPh)PPh 2-κ C:κ P}(cod)} 2] ( 19). All complexes were fully characterized spectroscopically and complexes 15b, 15c, 12·4THF and 19·THF additionally by X-ray diffraction analysis. DFT calculations of zwitterionic complexes gave insight into the coordination mode of the [Ph 2PCHS(O)Ph] ligand (κ P,κ S versus κ P,κ O).