Toward the Observation of the Tin and Lead Analogs of Formaldehyde

Abstract

Heavy aldehyde and ketone analogues, R 2 X�O (X = Si, Ge, Sn, or Pb), differ from their R 2 C�O counterparts due to their greater tendency to oligeramize as the X�O bond polarity increases as one goes down the periodic table. To date, H 2 Sn�O and H 2 Pb�O have eluded experimental detection. Herein we present the most rigorous theoretical study to date on these structures, providing CCSD(T)/pwCVTZ fundamental frequencies computed on CCSD(T)/CBS optimized structures for the H 2 X�O (X = Sn, Pb) potential energy surface. The focal point approach is employed to produce the CCSDTQ/CBS relative energies. For the Sn and Pb structures, the carbene-like cis-HXOH was the global minima, with the trans species being less than 0.6 and 1.1 kcal mol −1 above the cis structures, respectively. The formaldehyde-like H 2 X�O structure is in an energy well of at least 34.8 and 25.4 kcal mol −1 for Sn and Pb, respectively. Our results provide guidance for future work that may detect H 2 Sn�O or H 2 Pb�O for the first time.

MQM 2022: The 10th Triennial Conference on Molecular Quantum Mechanics

“…Kitzmiller and co-workers in the Schaefer group at the University of Georgia report predictions of the molecular structure and fundamental vibrational frequencies of two formaldehyde analogues based on two elements in the same group as carbon: tin and lead. 29 Using high-level coupled cluster methods combined with focal-point techniques, they provide accurate data intended to guide future experimental detection of these species. In the sole paper of the MQM VSI appearing in section A2, "Aerosols; Environmental and Atmospheric Chemistry; Astrochemistry," Haney et al in the Fortenberry group at Ole Miss explore the dependence of the lowest excitation energies of carbonic acid clusters on their dihedral O− C−O−O angles.…”

“…Kitzmiller and co-workers in the Schaefer group at the University of Georgia report predictions of the molecular structure and fundamental vibrational frequencies of two formaldehyde analogues based on two elements in the same group as carbon: tin and lead . Using high-level coupled cluster methods combined with focal-point techniques, they provide accurate data intended to guide future experimental detection of these species.…”