A stabilized cyclic alkene composition comprising one or more cyclic alkenes, and at least one antioxidant compound having the formula (I), wherein R1 through R5 can each independently be H, OH, C1-C8 linear, branched, or cyclic alkyl, C1-C8 linear, branched, or cyclic alkoxy or substituted or unsubstituted aryl, and wherein the antioxidant compound is present in an amount between 1 ppm and 200 ppm and has a boiling point lower than 265° C. A method for forming a layer of carbon-doped silicon oxide on a substrate, which uses the stabilized alkene composition and a silicon containing compound.