Studies On Syntheses Of Ph₂P-based Complexes

Hydrogen is a clean and renewable fuel and replaces fossil fuels in the future, therefore modeling the catalytic hydrogen-generation of hydrogenases is becoming a hot topic of organometallic chemistry. In view of phosphorus and sulfur-containing ligands exhibiting a wide variety of coordination modes and having strong coordinate ability, to mimic hydrogenases, developing new synthetic methodologies for model compounds is of particular significance.In this paper, reactions of different phosphorus and sulfur-containing ligands with iron carbonyls or nickel acetate have been investigated. Some new complexes are obtained and found to in part show catalytic activity.1. Different phosphinothioamides (A, B) were synthesized from the reaction of diphenylphosphine with isothiocyanates. Then the phosphinothioamides reacted with Fe3(CO)12 at room temperature to generate compounds 0 and 1. Compound 1 reacted with electrophiles in the presence of K2CO3 to afford compounds 2 and 3. Compound 1 reacted with Me3NO to offer compound 4. Compounds 0 and 1 reacted with Fe3(CO)12 in the presence of Et3N and NaH to give compounds 5,6,7 and 8. All the complexes were characterized by IR, NMR and single crystal X-ray crystallography. By cyclic voltammetry,1,5,6 and 8 were found to show catalytic activity toward hydrogen production.2. Ligand C was synthesized by the sulfurization of Ph2PH. It reacted with Fe3(CO)12 in THF to generate compounds 9,10 and 11. Also, ligands D and E were synthesized by the sulfurization of A and B, then the ligands reacted with Fe3(CO)12 to offer compound 12 and 13. In addition, ligands F and G containing P=S bond were synthesized using Ph2PCl as raw material. All the compounds were characterized by IR, NMR and single crystal X-ray crystallography.3. Complexes 14,15 and 16 containing nickel were synthesized from the reaction of A with nickel acetate at room temperature. In addition,2-(pyridyl)diphenyl phosphine (H) was prepared from Ph2PCl and 2-C5H4NLi, then complexes 17,18 and 19 were synthesized from the reaction of H with Fe3(CO)12 at room temperature. All the complexes were characterized by IR, NMR and single crystal X-ray crystallography.18 was founded to have catalytic activity of hydrogen production by electrochemical tests.