We calculated the equilibrium geometries and harmonic vibrational frequencies of the ground state and five cationic states of dichloroketene using (TD‐)B3LYP, PBE0, and M06/M06‐2X approaches. The photoelectron spectra of dichloroketene were simulated by computing Franck‐Condon factors. The ionization energies were computed using the CCSD(T) approach with extrapolation to the complete basis set (CBS) limit. We propose two new CBS energy formulas (E = ECBS + Aexp(‐x) + B/(x−1) n, n = 2 or 3) and compare the performance of different CBS approaches. A new ionic state of dichloroketene belonging to the Cs point group is reported. This state is identified as the first excited state of Cl2CCO+ having a double‐well potential‐energy curve along the CCO bending mode with a barrier height of 1.335 eV. The simulated photoelectron spectra are in agreement with the experiment. The vertical ionization energies calculated via spectral simulation are more accurate compared with those obtained at the ground‐state structure. Among the CBS formulas used, the proposed ansatz with n = 2 performs best, with a mean absolute error of 0.021 and 0.012 eV for the adiabatic and vertical ionization energies, respectively.

This study uses waste silicone as a low‐cost material to prepare the solid base catalyst using Li2CO3 as an activating agent through a solid state reaction for the biodiesel production. A sample of waste silicone is converted into SiO2 powder by being heated at 800 °C for 4 h. The results show that a highly active solid catalyst could be obtained by mixing and well grinding SiO2 powder with Li2CO3 calcined in air for 4 h. The prepared solid base catalysts are characterized by XRD, BET, SEM and FTIR for the physical and chemical properties. In the present study, the biodiesel is synthesized from soybean oil through a transesterification reaction catalyzed by the solid base catalyst. Under the optimal reaction conditions of methanol/oil molar ratio 12:1, 6% (wt/wt oil) catalyst amount, and a reaction temperature of 62 °C for 3 h, there is a 99.04 ± 0.9% conversion to the biodiesel from soybean oil. The waste silicone as the solid base catalyst demonstrates excellent catalytic activities and stable catalytic activities in transesterification reactions.