| Abstract
| - A cobaltocene catalyst effected a cycloaddition copolymerizationof 1,11-dodecadiyne (1a)with acetonitrile (2a) in toluene at 150 °C to afford apoly(pyridine) with a molecular weight up to 18 000.An excess of 2a to 1a was necessary for thepreparation of a soluble poly(pyridine) without diynetrimerization units. The structure of the nitrile influencedremarkably its copolymerizability with 1a: the copolymerizability order was p-tolunitrile >acetonitrile > n-octyl cyanide. The length(m) of amethylene chain tethering two C⋮C bonds of a diyneHC⋮C(CH2)mC⋮CH controlledthe diyne/nitrilecopolymerization: 1,9-decadiyne with m = 6 or1,7-octadiyne with m = 4 did not copolymerize with2aeffectively to give a diyne trimer or a bicyclic pyridine as a mainlow-molecular weight product, respectively.The poly(pyridine) formation is the first example of anefficient cycloaddition copolymerization of a terminaldiyne.
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