Matrix isolation and ab initio study on HCN/CO2 system and its radiation-induced transformations: Spectroscopic evidence for HCN⋯CO2 and trans-HCNH⋯CO2 complexes

Abstract

Spectroscopic characteristics and X-ray induced transformations of the HCN⋯CO complex in solid Ar and Kr matrices were studied by FTIR spectroscopy and ab initio calculations at the CCSD(T) level. The complex was prepared by deposition of the HCN/CO/Ng gas mixtures (Ng = Ar or Kr). The comparison of the experiment and calculations prove formation of a linear, H-bonded NCH⋯OCO complex with a substantial red shift of the C-H stretching band and a blue shift of the H-C-N bending band in respect to the monomer. This result is in contrast with the previous gas-phase observations, where only T-shape complex was found. Irradiation of deposited matrices leads to formation of CN radicals and HNC molecules and subsequent annealing results in appearance of HCN and trans-HCNH in both matrices plus HKrCN in the case of Kr. In the presence of CO, the strongest absorption of trans-HCNH radical demonstrates an additional blue-shifted (by 6.4 cm) feature, which was assigned to the N-coordinated complex of this radical with CO on the basis of comparison with calculations. To our knowledge, it is the first experimentally observed complex of this radical. No evidence was found for HKrCN⋯CO complex, which was explained tentatively by steric hindrance.

Surface Ligand Promotion of Carbon Dioxide Reduction through Stabilizing Chemisorbed Reactive Intermediates

“…This shift suggests that there is a chemical interaction between NH 2 and CO 2 as well as the reaction intermediates. The peak locating at ~839 cm -1 , attributed to the CO 2 bonding with -NH 2 , appears under the applied potential 32 , which further confirms the chemisorbing CO 2 taking place on C 2 -Ag NPs during the electrolysis. In contrast, the Ag-CO intermediate adsorption peak becomes negligible in the cases of C 11 -Ag NP ( Figure 3A) and ligand-free Ag NPs ( Figure S4) as the CO 2 RR catalysts.…”

Atomic basis functions for molecular electronic structure calculations

“…The atomic basis sets are now made available 93 that allow quantitative calculations of the structure and energetics of typical molecular systems. We are somewhat sorry for our belated report, for they have already been, and are being, used by our colleagues in their studies of unusual molecules under the unusual conditions of lowtemperature high-energy chemistry [94][95][96][97][98][99][100] .…”

Polyacrylamide‐Mediated Silver Nanoparticles for Selectively Enhancing Electroreduction of CO2 towards CO in Water

“…These two observations further confirm the chemisorbing CO 2 taking place over AgNPs@PAM during the electrolysis, and the activation of CO 2 is likely to be achieved through the formation of hydrogen bonds between the active hydrogen atoms in the amide group and the oxygen atoms in CO 2 . [50,51] In addition, the UV/Vis spectra of 300 mg L À 1 PAM aqueous solution in N 2 and CO 2 atmosphere were measured to further examine the formation of hydrogen bond between PAM and CO 2 . As shown in Figure 5b, the distinct absorption peaks observed around 200 nm in N 2 atmosphere can be assigned to the n!π* electronic transition resulted from the p-π conjugate effect of amide group in PAM.…”