A matrix isolation study of the Cs symmetric OCNO(X 2A″) radical

Abstract

Here we report the first experimental detection of the C(s) symmetric nitroformyl radical, OCNO(X 2A'') in a nitrogen-carbon dioxide matrix at 10 K using a Fourier transform infrared spectrometer (FTIR). The nu1 vibrational frequency was observed at 2113 cm(-1). This assignment was confirmed by follow-up experiments using isotopically labeled reactant molecules (15N, 18O, 13C). To synthesize this radical, we irradiated solid nitrogen-carbon dioxide ice mixtures with energetic electrons at 10 K. Suprathermal nitrogen atoms in their electronic ground and/or first electronically excited state were generated via the radiation induced degradation of molecular nitrogen; these atoms could then react with carbon dioxide to eventually yield the nitroformyl radical. We also investigated the kinetics of the formation of the nitroformyl radical and support the arguments with computations on the doublet and quartet OCNO potential energy surfaces (PESs).

Oxygen‐Substituted Isocyanates: Blocked (Masked) Isocyanates Enable Controlled Reactivity

“…The synthesis and isolation of O ‐isocyanates has been a longstanding challenge, with documented unsuccessful attempts . In contrast, solid evidence of these rare reactive intermediates has been obtained from spectroscopic data, for example via the thermolysis of N ‐methoxycarbonyl‐ O ‐methylhydroxylamine and the photolysis of methyl azidoformate . However, the rare reactions of O ‐isocyanates were most frequently encountered during unanticipated Lossen‐ rearrangements of O ‐activated‐hydroxylamines .…”

“…Today, isocyanates have a wide range of applications (> 100,000 publications & patents) and yearly global sales over 10 billion E. While carbonsubstituted isocyanates are ubiquitous, O-isocyanates are rare, despite interest in their reactivity for over a century. [3][4][5] However, the rare reactions [6] of O-isocyanates were most frequently encountered during unanticipated Lossen-rearrangements of O-activated-hydroxylamines. The synthesis and isolation of O-isocyanates has been a longstanding challenge, with documented unsuccessful attempts.…”

“…[2] In contrast, solid evidence of these rare reactive intermediates has been obtained from spectroscopic data, for example via the thermolysis of N-methoxycarbonyl-O-methylhydroxylamine and the photolysis of methyl azidoformate. [3][4][5] However, the rare reactions [6] of O-isocyanates were most frequently encountered during unanticipated Lossen-rearrangements of O-activated-hydroxylamines. [7] Unfortunately, once formed O-isocyanates often promptly engage in homotrimerization to the corresponding aromatic isocyanurate.…”

Photochemical Formation of Diazenecarbaldehyde (HNNCHO) and Diazenecarbothialdehyde (HNNCHS) in Low-Temperature Matrices

“…Due to the latter advantage MI spectra can be straightforwardly correlated both with spectra obtained by quantum chemical computations and by astrophysical observations. Therefore, it is not surprising that MI spectroscopy has been extensively applied to generate and characterize reactive molecules with astrochemical interest. − …”

Monocyclic and bicyclic CO4: how stable are they?

“…Besides CO and CO 2 that have a well-known direct bearing on human life, the high-order carboxides CO n (n > 2) have been receiving growing attention in the last decades. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] They can be produced in the reactions of oxygen (atomic or molecular) with the lower oxides of carbon, hydrocarbons, and other organic molecules. 26 CO n and their ions are also relevant to the chemistry of the terrestrial 27 and planetary 28 atmospheres.…”