POLYMERIZATIONS OF ACETYLENES AND CYCLIC OLEFINS INDUCED BY METAL CARBYNES.

Article abstract of DOI:10.1021/ja00321a029

trans-Bromotetracarbonyl(phenylmethylidyne)tungsten and related metal carbynes induce acetylenes and cycloalkenes to polymerize. The acetylenes include examples that are monosubstituted, disubstituted, and unsubstituted, as well as the first reported functionalized acetylenes in which the functional groups (the nitrile, ester, and halogen functions were studied) are not attached to the triple bond. The cycloalkenes yield polyalkenamers whose double bonds are largely cis. This last polymerization is speeded by the presence of oxygen. The stereochemistries of the polyacetylenes and the polynorbornenamer produced when the initiator is the metal carbyne are similar to those of the polymers produced when the initiator is pentacarbonyl(methoxyphenylmethylene)tungsten. A possible mechanism is presented to account for why the metal carbynes behave as though they were sources of reactive metal carbenes.