On the similar spectral manifestations of protonic and hydridic hydrogen bonds despite their different origin.

Previously studied complexes with protonic and hydridic hydrogen bonds exhibit significant similarities. The present study provides a detailed investigation of the structure, stabilization, electronic properties, and spectral characteristics of protonic and hydridic hydrogen bonds using low-temperature infrared (IR) spectroscopy and computational methods. Complexes of pentafluorobenzene with ammonia (C₆F₅H⋯NH₃) and triethylgermane with trifluoroiodomethane (Et₃GeH⋯ICF₃) were analyzed using both experimental and computational tools.

A Novel Abiotic Pathway for Phosphine Synthesis over Acidic Dust in Venus' Atmosphere.

Recent ground-based observations of Venus have detected a single spectral feature consistent with phosphine (PH) in the middle atmosphere, a gas which has been suggested as a biosignature on rocky planets. The presence of PH in the oxidized atmosphere of Venus has not yet been explained by any abiotic process. However, state-of-the-art experimental and theoretical research published in previous works demonstrated a photochemical origin of another potential biosignature-the hydride methane-from carbon dioxide over acidic mineral surfaces on Mars.

Infrared Spectra of Small Radicals for Exoplanetary Spectroscopy: OH, NH, CN and CH: The State of Current Knowledge.

In this study, we present a current state-of-the-art review of middle-to-near IR emission spectra of four simple astrophysically relevant molecular radicals-OH, NH, CN and CH. The spectra of these radicals were measured by means of time-resolved Fourier transform infrared spectroscopy in the 700-7500 cm spectral range and with 0.07-0.

Hydrogen Bonding with Hydridic Hydrogen-Experimental Low-Temperature IR and Computational Study: Is a Revised Definition of Hydrogen Bonding Appropriate?

Spectroscopic characteristics of MeSi-H···Y complexes (Y = ICF, BrCN, and HCN) containing a hydridic hydrogen were determined experimentally by low-temperature IR experiments based on the direct spectral measurement of supersonically expanded intermediates on a cold substrate or by the technique of argon-matrix isolation as well as computationally at harmonic and one-dimensional anharmonic levels. The computations were based on DFT-D, MP2, MP2-F12, and CCSD(T)-F12 levels using various extended AO basis sets. The formation of all complexes related to the redshift of the Si-H stretching frequency upon complex formation was accompanied by an increase in its intensity.

New physical insights: Formamide discharge decomposition and the role of fragments in the formation of large biomolecules.

In this work we present a time-resolved FTIR spectroscopic study on kinetics of atomic and molecular species, specifically CO, CN radical, N, HCN and CO generated in a glow discharge of formamide-nitrogen-water mixture in a helium buffer gas. Radicals such as NH, CH and OH have been proven to be fundamental stones of subsequent chemical reactions having a crucial role in a prebiotic synthesis of large organic molecules. This work contains three main goals.