ĊH3⋅⋅⋅13CO2 pairs in irradiated single crystals of CH313CO2Li⋅2D20

Abstract

The ĊH₃ radical trapped in irradiated single crystals of CH₃ ¹³CO₂Li⋅2D₂O has been found to interact with a ¹³CO₂ molecule, which is formed from the C–C bond breakage as a counterpart. The ¹³C superhyperfine coupling tensor was determined to be (−4.0, −3.3, −3.5) G. The ¹³CO₂ molecule is located in the direction of the unpaired electron orbital of ĊH₃ with the molecular axis perpendicular to it. The spectrum arising from the electron excess center CH₃ ¹³ĊO₂²⁻ was also detected together with the ĊH₃ radical. Our results indicate that the ĊH₃⋅⋅⋅¹³CO₂ pair is essentially a positive hole center formed from one electron loss followed by the C–C bond breakage.