Intramolecular intermetallic interactions in bi- and tetrametallic organometallic complexes as demonstrated with cyclic voltammetry

With bis(alkynyl) titanocene ligands acting as chelating moieties for low-valent transition-metal heterobimetallic Ti(IV)M(I) (M=Cu, Ag), complexes of the type {[Ti](CCSiMe3)}MX ([Ti](η5-C5H4SiMe3)2Ti; X=Cl; Br; I) were prepared. On reacting such complexes with {[Ti](CCSiMe3)2}MX′ (X′=OClO3) tetrametallic species of the type [{[Ti](CCSiMe3)2}MXM{(Me3SiCC)2[Ti]}]+ are formed. Their redox electrochemistry was studied with cyclic voltammetry (CV); for comparison, data of related bimetallic complexes were obtained. Results indicate a strong intramolecular interaction between the Group 11 metal held in place by the organometallic {[Ti](CCSiMe3)2} π-tweezers.