Highly Selective Formation of tert‐Butyl Hydroperoxide from the Reaction of Isobutane and O2 in a Zeolite under Visible Light

Isobutane and oxygen gas loaded into zeolite BaY react upon irradiation with green or blue light to yield tert‐butyl hydroperoxide in a single‐photon process. This was discovered when monitoring the reaction at room temperature in situ by FT‐infrared spectroscopy. Selectivity was 98%, even upon conversion of more than half of the reactants loaded into the zeolite. Diffuse reflectance spectra revealed a visible absorption tail which originates from an isobutane · O2 collision complex. It is attributed to the isobutane · O2 contact charge‐transfer absorption, whose onset is shifted from the UV into the visible region by the high electrostatic field of the zeolite.