In the continuing discovery of new catalytic reactions, compounds that contain two very different metal centers, in particular, have attracted considerable interest. The synthesis, structure and chemistry of these compounds called heterobimetallic complexes have grown steadily over the past few decades. In complexes where one metal is from the main group and the other is a transition metal, the modification of the dynamic behavior and chemical reactivity of the complex over that of the monometallic species makes heterobimetallic complexes synthetically useful. In this book, the synthesis, characterization, heterobimetallic complexes and dynamic behavior of the organotin compounds of cycloheptatriene and cyclooctatetraene are described. The applications in physical chemistry brought about by the special longchain structure of some of these complexes are also studied.