Ruthenium bipyridyl compounds with two terminal alkynyl ligands

摘要

Compounds of the form Ru(X_2bipy)(PPh_3)_2(-C ident to CC_6H_4NO_2-p)_2 (X_2bipy = 4,4'-X_2-2,2'-bipyridine,X = Me 3a,Br 3b,I 3c) have been synthesised from the mono-alkynyl precursors Ru(X_2bipy)(PPh_3)_2(-C=CC_6H_4NO_2-p)Cl (X = Me 2a,Br 2b,I 2c);the former are the first ruthenium bis-alkynyl compounds that also contain a bipyridyl ligand.Spectroelectrochemical investigation of 3a shows that the metal is readily oxidised to form the ruthenium(III) compound 3a+,and will also undergo a single-electron reduction at each nitro group to form 3a~(2-).ESR and UV/visible spectra of these redox congeners are presented.We also report the synthesis of [Ru(Me_2bipy)(PPh_3)_2-(-C ident to CBu~t)(N=N)][PF_6] 4 during the attempted synthesis of Ru(Me_2bipy)(PPh_3)_2(-C=CBu~1)_2,and report its X-ray crystal structure and IR spectrum.X-Ray crystal structures of 3b and 3c (as two different solvates) are presented,and the nature of the intermolecular interactions seen therein is discussed.Z-Scan measurements on Ru(Me_2bipy)(PPh_3)_2-(-C ident to CR)Cl (R = C_6H_4NO_2-p 2a,Bu~t,Ph,C_6H_4Me) are also reported,and show that Ru(Me_2bipy)(PPh_3)_2(-C ident to CR)-Cl (R = C_6H_4NO_2-p 2a,Ph) exhibit moderate third-order non-linearities.