Synthesis And Reactions Of Methyl(aryl)metal Complexes

This thesis describes the synthesis of methyl(aryl)platinum(II), -gold(III) and -titanium(IV) complexes and their reactions with electrophiles and with unsaturated reagents. Methyl or phenyl for halogen exchange reactions of dimethyl- and diphenyltitanium complexes are also discussed.;The electrophilic reagents HCl and HgCl(,2) selectively cleave the methyl-platinum bond in the complexes cis- PtMeAr(PMePh(,2))(,2) (Ar = Ph, 4-MeOC(,6)H(,4)), whereas in the complexes cis- AuMe(,2)PhL (L = PMe(,3), PPh(,3)) the phenyl-gold bond is preferentially cleaved. It is argued that the difference in reactivity of the gold and platinum complexes indicates the operation of different mechanisms of electrophilic cleavage.;SO(,2) inserts selectively into the metal-methyl bond of cis- PtMeAr(PMePh(,2))(,2) (Ar = Ph, 4-MeOC(,6)H(,4)) and cis- AuMe(,2)PhL (L = PMe(,3), PPh(,3)), giving the S-sulfinate complexes cis- Pt(SO(,2)Me)Ar(PMePh(,2))(,2) and AuMe(SO(,2)Me)PhL . It is argued that SO(,2) does not behave as a classic electrophile, and the mechanism may involve coordination of SO(,2) to the metal prior to insertion.;Reaction of hexafluorobut-2-yne with cis- PtMeAr(PMePh(,2))(,2) (Ar = Ph, 4-MeOC(,6)H(,4)) gives cis- PtMe C(CF(,3))=C(CF(,3))Ar (PMePh(,2))(,2) .;The synthesis and reactions with electrophiles of a series of methyl(aryl)titanium(IV) complexes TiMeAr((eta)(\u275)-C(,5)H(,5))(,2) are described. The electrophiles HCl, HOAc, HgCl(,2) and HgClMe show little selectivity for cleavage of a titanium-aryl vs. a titanium-methyl bond, except in the case where Ar = 4-MeOC(,6)H(,4). Methyl or phenyl for halogen exchange reactions between TiR(,2)((eta)(\u275)-C(,5)H(,5))(,2) (R = Me, Ph) and TiX(,2)((eta)(\u275)-C(,5)H(,5))(,2) (X = F, Cl, Br, I) are described. In general, TiMe(,2)((eta)(\u275)-C(,5)H(,5))(,2) and TiPh(,2)((eta)(\u275)-C(,5)H(,5))(,2) react at similar rates. Possible mechanisms for the reactions of the organotitanium complexes are discussed