## Disciplines

Numerical Analysis and Scientific Computing | Physical Chemistry

## Abstract (300 words maximum)

N_{2}…HCO^{+} and N_{2}H^{+}…OC are predicted to exist in interstellar clouds. These complexes involve HCO^{+} and N_{2}H^{+} fragments that are bound to N_{2} and CO, respectively using hydrogen-bonded interaction. The reason these molecules are important is that the existence of nitrogen can be measured indirectly through ion-molecular complexes studied in this work. The measured vibrational spectra of molecules is an excellent way to characterize and detect molecules. We used B3LYP, MP2, and CCSD(T) computational methods to predict the structure and vibrational frequencies of N_{2}…HCO^{+} and N_{2}H^{+}…OC and their fragments. The aug-cc-pVDZ and aug-cc-pVTZ basis sets were used. The stability of the complexes was described in terms of dissociations energies D_{e} and their zero-point energy (ZPE) corrected values, D_{o}. Both molecular complexes exhibit a linear geometry. Vibrational frequencies were obtained using normal mode analysis. The N_{2}H^{+}…OC proton transfer vibrations occur at around 1800 – 1900 cm^{-1}. H^{+} bound within HCO^{+} exhibit C-H vibration at ~2500-2700 cm^{-1}. The N_{2}…HCO^{+.} complex is more stable than N_{2}H^{+}…OC by ~7000 cm^{-1}. The ZPE corrected values for dissociation energies, D_{o} for N_{2}…HCO^{+} --> N_{2 }+ HCO^{+} and N_{2}H^{+}…OC --> N_{2}H^{+ }+ OC are ~3500 cm^{-1} and ~5000 cm^{-1}, respectively.

## Academic department under which the project should be listed

CSM - Chemistry and Biochemistry

## Primary Investigator (PI) Name

Martina Kaledin

Probing structure and energetics of proton-bound complexes N2…HCO+ and N2H+…OC using computational chemistry methods

N_{2}…HCO^{+} and N_{2}H^{+}…OC are predicted to exist in interstellar clouds. These complexes involve HCO^{+} and N_{2}H^{+} fragments that are bound to N_{2} and CO, respectively using hydrogen-bonded interaction. The reason these molecules are important is that the existence of nitrogen can be measured indirectly through ion-molecular complexes studied in this work. The measured vibrational spectra of molecules is an excellent way to characterize and detect molecules. We used B3LYP, MP2, and CCSD(T) computational methods to predict the structure and vibrational frequencies of N_{2}…HCO^{+} and N_{2}H^{+}…OC and their fragments. The aug-cc-pVDZ and aug-cc-pVTZ basis sets were used. The stability of the complexes was described in terms of dissociations energies D_{e} and their zero-point energy (ZPE) corrected values, D_{o}. Both molecular complexes exhibit a linear geometry. Vibrational frequencies were obtained using normal mode analysis. The N_{2}H^{+}…OC proton transfer vibrations occur at around 1800 – 1900 cm^{-1}. H^{+} bound within HCO^{+} exhibit C-H vibration at ~2500-2700 cm^{-1}. The N_{2}…HCO^{+.} complex is more stable than N_{2}H^{+}…OC by ~7000 cm^{-1}. The ZPE corrected values for dissociation energies, D_{o} for N_{2}…HCO^{+} --> N_{2 }+ HCO^{+} and N_{2}H^{+}…OC --> N_{2}H^{+ }+ OC are ~3500 cm^{-1} and ~5000 cm^{-1}, respectively.