Ortho-para mixing interaction due to the coupling of nuclear and electron spins was detected for the first time by millimeter-wave spectroscopy of the deuterated vinyl radical H2CCD. The ground state of H2CCD is split by the deuteron tunneling into two components 0+ and 0 - separated by ΔE0 =1186.794(16) MHz. Rotational levels in the 0+ and 0- states, one being an ortho level and the other a para level, are coupled by the interaction expressed by 〈0 ±|H′|0∓〉=(δa F/2)S ·(I1-I2), where I1 and I2 are spins of the two protons and S is the electron spin. The δaF constant has been determined to be 68.06(52) MHz. The para to ortho conversion rate constant is predicted to be 1.2×105 s-1 torr-1.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry