Syn Thesis And Properties Of A Se-coordinated Iron And Cobalt Complexes Supported By Trimethylphosphine

Transition metal hydrides are a kind of important organometallic compounds,which is widely usedin various fields,such as catalytic chemistry,synthetic chemistry and chemical industry.A series of transition metal hydrides has been prepared and many metal hydrides have been found to have a good catalytic performance in the activation reduction of olefins,alkynes,CO2,carbonyl compounds and the dehydrogenation of alcohols.Most of them are the hydrides of noble metal,such as ruthenium,rhodium,iridium,and so on.Compared to them,cheap metal has the advantage that unexpensive and environmental friendly,so to explore alternative cheap metal hydride has been a research hotspot.So far,a number of cheap metal hydrides have been prepared and many catalytic transformations involving these hydrides have been reported,in particular iron hydrido complexes.It is reported that some iron hydrido complexes possessed comparable catalytic performance with noble metal hydrides.The hydrido cobalt complexes used as catalysts for various catalytic reactions are less reported,however,it was widely accepted that hydrido cobalt complexes often acted as active intermediates in various catalytic reactions.In this paper,we first studied the reaction of selenophenol,2-methylselenophenol and 4-methoxyselenophenol with Co(PMe3)4,the novel selenium-coordinated organic cobalt complexes 1-4 were obtained and characterized,respectively.The mechanism of this kinds of reaction was investigated,and a new hydrido cobalt complex7 was synthesized by the reaction of PhSeLi,CoCl(PMe3)3 and PhSH.The catalytic property of hydrido cobalt(III)complex 2 was explored in the hydrosilylation of aldehydes and ketones.The reactions of complex 3 and 4 with carbon monoxide gave mononuclear dicarbonyl cobalt(I)complexes 5 and 6.The second part is based on the previous research in our laboratory.We further use the hydrido iron complex obtained by the reaction of(o-PPh2)PhSeH with Fe(PMe3)4 to react with CO,TMSA,phenylacetylene,acetylacetone,iodomethane and bromoethane.From the reaction of hydrido iron complex with CO,we isolated the carbonyl iron hydride complex 8 which have two isomers.The reaction of the hydrido iron complex with acetylacetone was confirmed by single crystal diffraction to produce the double chelated iron complex 11.In addition,we have studied the reaction of(o-PPh2)PhSeH with Co(PMe3)4,CoCl(PMe3)3 or CoMe(PMe3)4 and a double chelated cobalt complex 14 was obtained as a same product.