Carbonyl Selenide Research Articles

Computational study on the characteristics of the complexes resulting from the interaction of carbonyl selenide and hypohalous acids

This study computationally investigates the properties and competition of complexes formed by the interaction between hypohalous acids (HOX, where X = F, Cl, Br, and I) and carbonyl selenide (COSe) at the MP2/aug-cc-pVTZ computational level. Three distinct groups of complexes were obtained. The first group, consisting of complexes with a cyclic structure (HB-TB), exhibited the highest stability. remaining two groups formed less stable linear structures with different characteristics (ChB and XB). In the first group, the electronegativity of the halogen atom significantly influenced the stability of the complexes. Conversely, the stability of complexes in groups II and III was primarily determined by the acid and base strengths of the interacting monomers. To comprehensively evaluate the obtained results, various analyses were employed, including Molecular electrostatic potential (MEP), geometry Optimization, Spectroscopic, Interaction energy (SE), Natural bond orbital (NBO) analysis, Atoms in molecules (AIM) analysis, Non-covalent interaction (NCI) index, Energy decomposition analysis (EDA), and Electron density difference(EDD) analysis.

Direct hydrogen selenide (H2Se) release from activatable selenocarbamates.

Hydrogen selenide (H2Se) is a possible bioregulator, potential gasotransmitter, and important precursor in biological organoselenium compound synthesis. Early tools for H2Se research have benefitted from available mechanistic understanding of analogous small molecules developed for detecting or delivering H2S. A now common approach for H2S delivery is the use of small molecule thiocarbamates that can be engineered to release COS, which is quickly converted to H2S by carbonic anhydrase. To expand our understanding of the chemical underpinnings that enable H2Se delivery, we investigated whether selenocarbamates undergo similar chemistry to release carbonyl selenide (COSe). Using both light- and hydrolysis-activated systems, we demonstrate that unlike their lighter thiocarbamate congeners, selenocarbamates release H2Se directly with concomitant isocyanate formation rather than by the intermediate release of COSe. This reaction mechanism for direct H2Se release is further supported by computational investigations that identify a ΔΔG‡ ∼ 25 kcal mol-1 between the H2Se and COSe release pathways in the absence of protic solvent. This work highlights fundamentally new approaches for H2Se release from small molecules and advances the understanding of reactivity differences between reactive sulfur and selenium species.

Mapping the drivers of uncertainty in atmospheric selenium deposition with global sensitivity analysis

Abstract. An estimated 0.5–1 billion people globally have inadequate intakes of selenium (Se), due to a lack of bioavailable Se in agricultural soils. Deposition from the atmosphere, especially through precipitation, is an important source of Se to soils. However, very little is known about the atmospheric cycling of Se. It has therefore been difficult to predict how far Se travels in the atmosphere and where it deposits. To answer these questions, we have built the first global atmospheric Se model by implementing Se chemistry in an aerosol–chemistry–climate model, SOCOL-AER (modeling tools for studies of SOlar Climate Ozone Links – aerosol). In the model, we include information from the literature about the emissions, speciation, and chemical transformation of atmospheric Se. Natural processes and anthropogenic activities emit volatile Se compounds, which oxidize quickly and partition to the particulate phase. Our model tracks the transport and deposition of Se in seven gas-phase species and 41 aerosol tracers. However, there are large uncertainties associated with many of the model's input parameters. In order to identify which model uncertainties are the most important for understanding the atmospheric Se cycle, we conducted a global sensitivity analysis with 34 input parameters related to Se chemistry, Se emissions, and the interaction of Se with aerosols. In the first bottom-up estimate of its kind, we have calculated a median global atmospheric lifetime of 4.4 d (days), ranging from 2.9 to 6.4 d (2nd–98th percentile range) given the uncertainties of the input parameters. The uncertainty in the Se lifetime is mainly driven by the uncertainty in the carbonyl selenide (OCSe) oxidation rate and the lack of tropospheric aerosol species other than sulfate aerosols in SOCOL-AER. In contrast to uncertainties in Se lifetime, the uncertainty in deposition flux maps are governed by Se emission factors, with all four Se sources (volcanic, marine biosphere, terrestrial biosphere, and anthropogenic emissions) contributing equally to the uncertainty in deposition over agricultural areas. We evaluated the simulated Se wet deposition fluxes from SOCOL-AER with a compiled database of rainwater Se measurements, since wet deposition contributes around 80 % of total Se deposition. Despite difficulties in comparing a global, coarse-resolution model with local measurements from a range of time periods, past Se wet deposition measurements are within the range of the model's 2nd–98th percentiles at 79 % of background sites. This agreement validates the application of the SOCOL-AER model to identifying regions which are at risk of low atmospheric Se inputs. In order to constrain the uncertainty in Se deposition fluxes over agricultural soils, we should prioritize field campaigns measuring Se emissions, rather than laboratory measurements of Se rate constants.

Developments towards the delivery of selenium ion beams at ISOLDE

.The production of selenium ion beams has been investigated at the CERN-ISOLDE facility via two different ionization methods. Whilst molecular selenium (SeCO) beams were produced at ISOLDE since the early 1990s, recent attempts at reliably reproducing these results have so far been unsuccessful. Here we report on tests of a step-wise resonance laser ionization scheme for atomic selenium using the ISOLDE Resonance Ionization Laser Ion Source (RILIS). For stable selenium an ionization efficiency of 1% was achieved. During the first on-line radioisotope production tests, a yield of approx 2.4 times 10^4 ions/μC was measured for 71Se+, using a ZrO2 target with an electron impact ion source. In parallel, an approach for extraction of molecular carbonyl selenide (SeCO) beams was tested. The same ion source and target material were used and a maximum yield of approx 3.6times 10^5 ions/μ C of 71SeCO+ was measured.

Vibrational spectra, conformational properties and argon matrix photochemistry of diacetyl diselenide, CH3C(O)Se2C(O)CH3

By oxidation of selenoacetic acid, CH3C(O)SeH, we have prepared the hitherto unknown diacetyl diselenide, [CH3C(O)Se]2. Its vibrational properties were studied experimentally, both in neat liquid (Fourier transform infrared spectroscopy and Raman) with the molecule isolated in argon matrix at low temperatures and theoretically using MP2 and B3LYP methods in combination with 6‐31+G(d), 6‐311++G(3df,3dp) or aug‐cc‐pvDZ basis sets. Analysis of Ar matrix spectra reveals a conformational equilibrium in gas phase at room temperature, which was interpreted by considering only two of the three stable rotamers predicted by our three‐dimensional potential energy surface scans. Energetic properties of three minima found theoretically were further studied in terms of donor–acceptor interactions by using natural bond orbital calculations at the same levels of theory. From this, it was possible to rationalize the conformational stability order and molecular structures by means of vicinal hyperconjugative delocalizations involving lone pairs on selenium or oxygen atoms and C=O, C–C or Se–C antibonding orbitals. The photochemistry of the compound in the argon matrix in the range between 200 and 800 nm was also investigated, revealing only one photochemical path to produce ketene, H2C=C=O, methylselane, CH3SeH, and carbonyl selenide, OCSe. Copyright © 2016 John Wiley & Sons, Ltd.

Chalcogen-bonded complexes. Selenium-bound adducts of NH3, H2O, PH3, and H2S with OCSe, SCSe, and CSe2.

Recent ab initio investigations of some complexes formed between carbon dioxide and its analogues carbonyl sulfide, carbonyl selenide, carbon disulfide, and thiocarbonyl selenide and the common bases ammonia, water, phosphine, and hydrogen sulfide have revealed significant differences between the properties of those complexes bound through the oxygen atom of the electron acceptor and their counterparts in which the interaction takes place through a sulfur atom. In each case the interaction is weak, but the structures, interaction energies, and vibrational spectra of the complexes show some regular variations in behavior as the base and the acid are systematically changed. The adducts bound through sulfur present examples of the type of non-covalent interaction known as the chalcogen bond. In this paper we extend the range of electron acceptors to include carbon diselenide, and we explore the effects of substituting selenium for sulfur as the acceptor atom in the complexes of OCSe, SCSe, and CSe2. These adducts are also classified as chalcogen-bonded complexes, and have many features in common with the sulfur-bonded species, but also exhibit some noticeable differences between the two series.

Chalcogen-bonded complexes of some carbon dioxide analogues

Ab initio calculations have been carried out on the sulphur-bonded van der Waals complexes formed between the carbon dioxide analogues carbonyl sulphide, carbon disulphide and thiocarbonyl selenide, and the common electron donors ammonia, water, phosphine and hydrogen sulphide. The structures of these twelve complexes are all similar, and involve an approximately linear XCS⋯Y fragment (X=O, S, Se; Y=N, O, P, S). These structures contrast with those of the oxygen-bound complexes of carbon dioxide, carbonyl sulphide and carbonyl selenide reported earlier which, with the exception of the hydrogen sulphide species, are characterized by four-membered rings with varying orientations involving the C, O, H and Y atoms. The molecular structures, interaction energies and vibrational spectra have been studied, and the variations in these properties have been correlated with the complex structures and with the molecular quadrupole moments of the acid monomers.

Matrix isolation studies of carbonyl selenide, OCSe: Evidence of the formation of dimeric species, (OCSe)2

OCSe isolated in solid Ar or N2 at 10K was investigated by FTIR spectroscopy. The IR spectra of OCSe diluted in a 1:1000 proportion with the matrix gases were interpreted in terms of monomeric carbonyl selenide in a single matrix site. The IR spectra of more concentrated matrices revealed several new IR absorptions, which were tentatively assigned to different dimeric structures, aided by the prediction of quantum chemical calculations. The different matrices were exposed to UV–visible broad-band radiation, finding that monomeric OCSe decomposes into CO and Se, as evidenced by the IR absorption of CO perturbed by the presence of a selenium atom in the same matrix cage, while dimeric forms of OCSe decompose giving mainly (CO)2.

Selective Insertion of Oxygen and Selenium into an Electron-Precise Paramagnetic Selenium−Manganese Carbonyl Cluster [Se6Mn6(CO)18]4−

The facile synthesis of a novel electron-precise paramagnetic hexamanganese carbonyl selenide cluster [Se(6)Mn(6)(CO)(18)](4-) (1) was discovered, which demonstrates contrasting reactivity toward O(2) and Se(8) under markedly mild conditions to afford the O- and Se-inserted clusters [Se(6)Mn(6)(CO)(18)(O)](4-) (2) and [Se(10)Mn(6)(CO)(18)](4-) (3), respectively. Clusters 1-3 represent the first examples of electron-precise paramagnetic main-group transition metal carbonyl clusters, and their formation and bonding properties are further elucidated by theoretical calculations.

Metal and phosgene-free synthesis of 1H-quinazoline-2,4-diones by selenium-catalyzed carbonylation of o-nitrobenzamides

1h-quinazoline-2,4-diones were efficiently synthesized by selenium-catalyzed carbonylation of o-nitrobenzamides under relatively mild conditions. in situ-generated carbonyl selenide (seco) is proposed to initiate the catalytic carbonylation. thus, a concise transition metal and phosgene-free synthetic route to potentially bioactive-substituted 1h-quinazoline-2,4-dione derivatives has been developed. (c) 2010 elsevier ltd. all rights reserved.

Highly Efficient Route to Diselenides from the Reactions of Imines and Selenium in the Presence of Carbon Monoxide and Water

AbstractReactions of selenium with imines (RR1CNR2) of aldehydes and ketones in the presence of carbon monoxide, water and triethylamine lead to reductive selenation, on aerobic work‐up, to afford symmetrical diselenides (RR1CHSe)2 in good to excellent yields. The proposed mechanism suggests that both in situ generated carbonyl selenide (SeCO) and hydrogen selenide (H2Se) are involved in the reaction.

On-line gas-phase separation of short-lived bromine nuclides from precursor selenium

Short-lived bromine nuclides, available from thermal neutron induced nuclear fission of235U, may be useful tracers for laboratory studies in atmospheric chemistry. Short-lived fission products were delivered continuously to a laboratory with the gas-jet facility at the spallation neutron source SINQ. To increase the selectivity for the fission products from the light mass peak, the235U target was covered with a nickel foil to suppress the heavy fission products having lower recoil energies. In addition, carbon monoxide (CO) or propene (C3H6) were added as reactive gases to the He carrier gas rather than aerosol particles. Besides isotopes from the noble gas krypton and its descendants, a selective transport of selenium isotopes was observed with each of these gases, though with higher yield using CO/He. Through β--decay bromine isotopes are formed from selenium precursors. A bromine generator was established through controlled decomposition of the transported carbonyl selenide (OC83-87Se) and adsorption of the resulting elemental selenium on quartz. The addition of carrier bromine to the carrier gas led to a complete mobilisation of the bromine nuclides from the quartz surface while retaining selenium. With this procedure, a source of gaseous bromine species, presumably in the form of Br2with the isotopes83-87Br, could be established.

ChemInform Abstract: Synthesis and Reactions of Carbonyl Selenide and Isoselenocyanates

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A Gas-Phase Basicity Scale for Selenocarbonyl Compounds Based on High-Levelab Initioand Density Functional Theory Calculations

A basicity scale for selenocarbonyl derivatives which covers a wide range of values (60 kcal/mol) has been established through the use of high-level ab initio and DFT calculations. In our theoretical survey we have included selenoformaldehyde and the corresponding BH2, CH3, NH2, F, and Cl mono- and disubstituted derivatives, as well as carbonyl selenide, thiocarbonyl selenide, and selenoketene. With the only exception of selenoketene, which is a carbon base, all selenocarbonyl compounds investigated behave as selenium bases in the gas phase. Selenocarbonyl derivatives are predicted to be equally or slightly more basic than the thiocarbonyl analogues and, therefore, more basic than the corresponding carbonyl compounds. We have also shown, by means of G2-type calculations, that substituent effects on the relative stability of the neutral and the protonated forms of selenocarbonyl series are also rather similar to those estimated, at the same level of theory, for the thiocarbonyl series. For the neutrals the...

Accurate ab initio prediction of the rovibrational energy levels and equilibrium geometry of carbonyl selenide (OCSe)

The geometry and the anharmonic force field of carbonyl selenide (OCSe) have been investigated using multi reference configuration interaction theory. The computed potential energy surface and geometry have been refined by a least squares adjustment of the theoretical spectroscopic parameters to reproduce all available spectroscopic frequencies and constants. The Fermi interaction between the 2ν2 and ν3 bands has been investigated in detail using perturbative and variational methods.

ChemInform Abstract: A New Synthesis of Selenol Esters via Carbophilic Addition of Organocopper Reagents to Carbonyl Selenide.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A New Synthesis of Selenol Esters via Carbophilic Addition of Organocopper Reagents to Carbonyl Selenide

A New Synthesis of Selenol Esters via Carbophilic Addition of Organocopper Reagents to Carbonyl Selenide

A Theoretical Study on the Generation Process of Carbonyl Selenide in Selenium Catalyzed Carbonylation of Amines

Abstract Ab initio molecular orbital calculations were performed in order to examine the regeneration pathways of carbonyl selenide which plays an important role in selenium catalyzed carbonylation of amines with carbon monoxide.

Novel synthesis of S-alkyl thiocarbamates from amines, carbon monoxide, elemental sulfur, and alkyl halides in the presence of a selenium catalyst

Carbonyl selenide easily reacted with elemental sulfur at low temperature to form carbonyl sulfide in a good yield, and reaction of ammonium salts of selenocarbamates with elemental sulfur brought about ready transformation to those of thiocarbamates. On the basis of the high catalytic activity of selenium for carbonylation of amines with carbon monoxide in addition to these important findings, a convenient new method for synthesis of S-alkyl thiocarbamates was developed through the carbonylation of amines with carbon monoxide and elemental sulfur in the presence of a selenium catalyst under mild conditions followed by alkylation of ammonium salts of the thiocarbamates with alkyl halides.

The Hyperfine Structure of OCSe

The J = 1-0 transition of several isotopomers of carbonyl selenide was measured by microwave Fourier transform spectroscopy. The quadrupole and spin-rotation coupling constants of 17O, the spin-rotation coupling constants of 13C and 77Se, and the spin-spin interaction constant DCSe were determined for the first time.