Coordination polymers

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Coordination polymer is the term given in inorganic chemistry to a metal coordination compound where a ligand bridges between metal centres, where each metal centre binds to more than one ligand to create a infinite array of metal centres.

Examples of such materials include many of the metal salts of benzene-1,3,5-tricarboxylic acid (trimesic acid). This has been one of the most popular polycarboxylic acids used in the synthesis of these polymers. Using this triacid and cobalt, manganese, zinc, cadmium, copper, lead and other metals a series of solid polymers have been made. Other carboxylic acids have been used to form polymers.

Another common synthetic method is to react a polypyridine whose geometry renders it unable to chelate a metal atoms with all its nitrogen atoms. For instance 4,4'-bipyridine can be used to form polymers with many metals. One of the most developed metals is cadmium, it is the case that cadmium nitrate reacts with a wide array of polypyridines to form different solids. One of the key developments is the use of exotic polypyridines where the pyridine rings are separated by covalent spacers such as prop-1,3-diyl groups.

Yet another method of forming coordination polymers is to use a donor atom which bears more than one lone-pair for instance this type of bridging has been seen in uranium flourides and the lead carboxylates.