Polyconjugated silicon polymers

The geometrical and electronic structure of polyconjugated silicon polymers was calculated by ab initio quantum-chemical methods. The polymers are bui lt from linear chains of Si atoms with polyyne and cumulene bond systems. T he results of calculations agree with the experimental data on the structur e of silicyne - an amorphous substance prepared by annealing hydrogenated a morphous silicon in vacuum. The agreement between the theoretical and exper imental data is interpreted as evidence in favor of the existence of poly-c onjugated silicon polymers in the form of the structural fragments of silic yne. The existence of such polymers points to the ability of elementary sil icon to form new allotropic forms analogously to carbon.