Organometallics metal chelation polymers

High MW, rigid-rod, conjugated transition metal acetylide polymers (42, Scheme 10) were synthesized by reaction of the dichloro iron or ruthenium chelated diphosphine complexes (40) with a te-trimethylstannylacetylide monomer (41). Reaction of the rhodium complex 43 with an equimolar amount of compound 44 gave a rigid-rod acetylide organometallic polymer 45 (Scheme 11). This ihodium-containing polymer was soluble in THE... 

It is clear from the preceding discussion that organometallic photoinitiators (metal carbonyl or chelate derivatives) can provide a convenient route for synthesizing vinyl polymers with a variety of different reactive end group or photoreactive pendant groups or side chains through the polymer chain. 

Almost 70 of the approximately 115 elements are transition metals. These are elements with electrons successively added to their d or f subshells and have both filled and unfilled orbitals suitable for bonding. They exhibit a variety of oxidation states and bond formations, such as sigma and pi bonds or coordination bonds as are found in typical chelate structures. These characteristics are the reason that transition metal-containing macromolecules exist in a wide variety of structures including linear, two-dimensional, three-dimensional, dendrite, and assemblies. Many of these polymers are often referred to as organometallic polymers. We have, somewhat arbitrarily, separated this class from coordination polymers, which have been covered in Volumes 1, 3, and 5. 

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