Experimental and theoretical study of Ne·CO cluster

The photoionization of Ne·CO complex in the energy region of 13.8-14.2 eV was investigated with photoionization mass spectrometry using a synchrotron radiation source in Hefei. The ionization energy (IE) of Ne·CO is determined to be 13.965 eV from its photoionization efficiency curve whose characterization is affected by the photoabsorption of CO molecule. The equilibrium geometry and harmonic vibrational frequencies of Ne·CO and Ne·CO+ are calculated using cc-pVTZ basis sets at the QCISD level of theory. The results indicate that they are of a skewed T-shaped structure and show the configuration changes accompanying the ionization of Ne·CO complex. The parameters of thermo-chemistry of Ne·CO and Ne·CO+ are calculated using Gaussian-2 method, which provide information concerning the reduction of the ionization potentials of CO in the Ne·CO complex, relative to that of the bare molecule.