Water Droplet Microlightning Sparks Alkyne Ozonolysis
Yifan Meng, Elumalai Gnanamani, Richard N. Zare
Abstract
We report that microlightning during the spraying of pure water microdroplets can cleave alkyne triple bonds via the in situ formation of ozone. When alkyne vapors are introduced into a spray of water microdroplets under ambient conditions, carboxylic acids are detected by high-resolution mass spectrometry (MS). Control experiments confirmed that both water and molecular oxygen in the gas surrounding the droplets are essential in this transformation. Intermediates of ozonolysis were captured by MS and tandem mass spectrometry (MS 2 ), which further verified the proposed mechanism through ozone generation from water droplet microlightning. Our findings demonstrate a green, catalyst-free method for breaking the C≡C bond of alkynes and forming the corresponding carboxylic acids.