Laser-induced polymerization of SiI4

The laser-induced polymerization of powdered SiI4 has been investigated by time-of-flight (TOF) mass spectroscopy combined with density functional theory (DFT) calculations. In the positive ion spectra, three series of abundant clusters ( Si n I 2 n + 1 + (n = 1–6), Si n I 4 n / 3 + 3 + (n = 7–15), Si n I 3 n / 2 - 7 + (n = 16–22)) were observed. DFT calculations have revealed that the abundant clusters are straight chains with iodine bridge in n = 1–6, multi-cyclic rings of pentagons in n = 7–15, and cages constructed by pentagons and hexagons in n = 16–22. A silicon-rich six-membered ring, i.e., an unsaturated ring like benzene, was detected in less abundant clusters