Book Synopsis Rhenium Complexes of Some Nitrogen-containing Ligands by :
Download or read book Rhenium Complexes of Some Nitrogen-containing Ligands written by and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 1,2-Dialkylhydrazines are cleaved at the N~ bond on reaction with oxotrichlorobis(triphenylphosphine)rhenium{V) to give alkylimido complexes of the type [Re(NR)C13(PPh3)2J. 1,2-Dibenzylhydrazine reacts anomalously to give a Re(IV) amido complex of the type Retention of the N-N bond occurs on reaction of I ,2-dioC'll::.oy111ydrazinc with oxotrichlorobis(triphenylphosphine)rhenium(V) in benzene-ethanol, and a novel chelated benzoylhydrazido complex is formed. Employment of benzene-acetone as reaction medium permits the isolation of new benzoylhydrazone complexes. The formation of chelate rings containing nitrogen is not restricted m,aroyl hydrazines, and dibenzamidc gives Cl complex analogous to the mown rhenium acetylacetonates. The chelated benzoylhydrazido complexes react rapidly with cyanides, pyridine, phosphines, halogens and carbon monoxide to give rhenium(III) benzoy.lazo complexes, containing the -N=NCOPh group. Prolonged treatment of the benzoylhydrazidc complex with ditertiary and certain monotertiary phosphincs gives a series of new rhenium(I) tctrakis(phosphine)dinitJ'ogcn complexes. The first fluorophosphine and phosphite dinitrogcn complexes have been prepared by this method. The complex [ReCl(N2)(PMe2Ph)4] has also been prepared from dinitr~gen gas by reduction of [RcC13(PMe2Pll)3] under a dinitrogen pressure of 80 atmospheres. 15N2 labelling has been --1 employed to confinn the assignment of strong infrared bands in 1900-2100cm region to v{N=N). Carbon .monoxide reacts with the chelated benzoylhydrazido or benzoy.l.a.co complexes to give bis{carbonyl)dinitrogen complexes. The N=N and C=O stretching vibrations are shown to be st.rongly coupled by 15NZ labelling, infrared bands in the 1900-2100cm- 1 and no assignments of region can be made.The rhenium(l) tetrakis(phosphine)dinitrogen complexes react with halogens and oxidising nletal salts to give the first series of paramagnetic dinitrogen complexes. Transition metal salts such as [MOCl4(Etp)2] react with [ReCl(N2)(P}.fe2Ph)4]to give dinitrogen bridged complexes with abnonnally low N=N stretching frequencies (1680-1850CJlt-1). Treatment of the bis(carbonyl)dinitrogen complexes with mono- and ditertiaryphosphincs provides a facile method for the preparation of rhenium(I) mono- and bis -carbonyl complexes.
