the reaction mixture comprising the nanoscale silicon particles is treated within the reactor with one or more compounds selected from the group of 1 alkenes and or 1 alkynes in a preferred embodiment the at least one 1 alkene and or the at least one 1 alkyne used for treating the as grown or essentially hydrogen terminated nanoscale silicon particles are selected from linear or branched 1 alkenes consisting of 3 to 25 carbon atoms and those consisting of 10 to 20 carbon atoms examples include h 2 c u2550 ch u2014 ch 2 7 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 8 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 9 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 10 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 11 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 12 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 13 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 14 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 15 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 16 u2014 ch 3 h 2 c u2550 ch u2014 ch 2 17 u2014 ch 3 the treatment of the as grown or essentially hydrogen terminated nanoscale silicon particles according to the invention comprises radical induced hydrosilylation thermally induced hydrosilylation photochemical hydrosilylation or hydrosilylation mediated by metal.