Polymers, organometallic transition metal containing

Acknowledgment is made to the Donors of the Petroleum Research Fund, administered by the American Chemical Society, and to the Materials Research Laboratory, University of Massachusetts (Amherst), for grants in support of this research. The National Science Foundation, through the Expedited Award for Novel Research at Stevens Institute, has enabled K.E.G. to develop the processing of such transition metal containing organometallic polymers. ... 

Structures and Properties of One-Dimensional Transition Metal-Containing Coordination/ Organometallic Polymers and Oligomers Built Upon Assembling Diphosphine and Diisocyanide Ligands... 

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. 

Two major approaches to the formation of materials of this type have involved the derivatization of preformed organic polymers with organometallic functions and the synthesis and polymerization of organometallic monomers that contain vinyl substituents For the transition metals, condensation polymerizations have also been investigated. However, the reactions have generally been conducted at elevated temperatures, and the resulting products have often not... 

The transition group compound (catalyst) and the metal alkyl compound (activator) form an organometallic complex through alkylation of the transition metal by the activator which is the active center of polymerization (Cat). With these catalysts not only can ethylene be polymerized but also a-olefins (propylene, 1-butylene, styrene) and dienes. In these cases the polymerization can be regio- and stereoselective so that tactic polymers are obtained. The possibilities of combination between catalyst and activator are limited because the catalytic systems are specific to a certain substrate. This means that a given combination is mostly useful only for a certain monomer. Thus conjugated dienes can be polymerized by catalyst systems containing cobalt or nickel, whereas those systems... 

Examples of organometallic polymers containing both phosphorus atoms and transition metals in the backbone include polyferrocenylphosphines 8 (and the corresponding phosphine sulfides 9), which are accessible via the thermal ROP of phosphorus-bridged [1] ferrocenophanes [16,17]. Polymers of this type have been previously prepared by condensation routes and the catalytic potential of some of their transition metal derivatives has already been noted [18]. Living anionic ROP of phosphorus-bridged [l]ferrocenophanes has recently been demonstrated and provides a route to block copolymers such as 10 (PI = poly-isoprene) [19] ... 

The research area of organometallic polymers containing transition metals cr-bonded in the polymer backbone is dominated by poly(metal acetylides).34,35 Since their discovery in the 1970s,... 

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