Superconductivity at 2.8 K and 1.5 kbar in .kappa.-(BEDT-TTF)2Cu2(CN)3: the first organic superconductor containing a polymeric copper cyanide anion

A laboratory river model for the study of self-purification inhibition in a stream containing toxic substances is presented. It enables an engineering - technological prediction of the impact of toxic substances or wastewaters on dissolved oxygen (DO) profile in an organically polluted river downstream from the point of entry of toxic effluent thus providing rapidly and inexpensively significant design information to an environmental scientist or engineer. The method was applied to the toxicity evaluation of wastewaters from electroplating industry. The effects of copper, cyanide (representing two significant constituents of this type of wastewaters) and wastewater from electroplating industry on the biodegradation of organic municipal pollution in receiving stream were evaluated experimentally.

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Selective observation of spin and charge dynamics in an organic superconductor λ−(BETS)2GaCl4 using Ga69,71 NMR measurements

Physical Review B ◽

10.1103/physrevb.102.235131 ◽

2020 ◽

Vol 102 (23) ◽

Author(s):

T. Kobayashi ◽

K. Tsuji ◽

A. Ohnuma ◽

A. Kawamoto

Keyword(s):

Organic Superconductor ◽

Charge Dynamics

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NMR Properties of the Cyanide Anion, a Quasisymmetric Two-Faced Hydrogen Bonding Acceptor

Symmetry ◽

10.3390/sym13071298 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1298

Author(s):

Ilya G. Shenderovich ◽

Gleb S. Denisov

Keyword(s):

Hydrogen Bonding ◽

Experimental Studies ◽

Polarizable Continuum Model ◽

Coupling Constants ◽

Scalar Coupling ◽

Cyanide Anion ◽

Molecular Systems ◽

Polarizable Continuum ◽

Chemical Shieldings ◽

Nmr Properties

The isotopically enriched cyanide anion, (13C≡15N)−, has a great potential as the NMR probe of non-covalent interactions. However, hydrogen cyanide is highly toxic and can decompose explosively. It is therefore desirable to be able to theoretically estimate any valuable results of certain experiments in advance in order to carry out experimental studies only for the most suitable molecular systems. We report the effect of hydrogen bonding on NMR properties of 15N≡13CH···X and 13C≡15NH···X hydrogen bonding complexes in solution, where X = 19F, 15N, and O=31P, calculated at the ωB97XD/def2tzvp and the polarizable continuum model (PCM) approximations. In many cases, the isotropic 13C and 15N chemical shieldings of the cyanide anion are not the most informative NMR properties of such complexes. Instead, the anisotropy of these chemical shieldings and the values of scalar coupling constants, including those across hydrogen bonds, can be used to characterize the geometry of such complexes in solids and solutions. 1J(15N13C) strongly correlates with the length of the N≡C bond.

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Evolution of Shape and Volume Fraction of Superconducting Domains with Temperature and Anion Disorder in (TMTSF)2ClO4

Crystals ◽

10.3390/cryst11010072 ◽

2021 ◽

Vol 11 (1) ◽

pp. 72

Author(s):

Kaushal K. Kesharpu ◽

Vladislav D. Kochev ◽

Pavel D. Grigoriev

Keyword(s):

Cooling Rate ◽

Annealing Time ◽

Volume Fraction ◽

Density Wave ◽

Spin Density Wave ◽

Finite Size ◽

Organic Superconductors ◽

Organic Superconductor ◽

Sample Length ◽

Sample Shape

In highly anisotropic organic superconductor (TMTSF)2ClO4, superconducting (SC) phase coexists with metallic and spin-density wave phases in the form of domains. Using the Maxwell-Garnett approximation (MGA), we calculate the volume ratio and estimate the shape of these embedded SC domains from resistivity data at various temperature and anion disorder, controlled by the cooling rate or annealing time of (TMTSF)2ClO4 samples. We found that the variation of cooling rate and of annealing time affect differently the shape of SC domains. In all cases the SC domains have oblate shape, being the shortest along the interlayer z-axis. This contradicts the widely assumed filamentary superconductivity along the z-axis, used to explain the anisotropic superconductivity onset. We show that anisotropic resistivity drop at the SC onset can be described by the analytical MGA theory with anisotropic background resistance, while the anisotropic Tc can be explained by considering a finite size and flat shape of the samples. Due to a flat/needle sample shape, the probability of percolation via SC domains is the highest along the shortest sample dimension (z-axis), and the lowest along the sample length (x-axis). Our theory can be applied to other heterogeneous superconductors, where the size d of SC domains is much larger than the SC coherence length ξ, e.g., cuprates, iron-based or organic superconductors. It is also applicable when the spin/charge-density wave domains are embedded inside a metallic background, or vice versa.

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Direct observation of long-lived cyanide anions in superexcited states

Communications Chemistry ◽

10.1038/s42004-021-00450-0 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Xiao-Fei Gao ◽

Jing-Chen Xie ◽

Hao Li ◽

Xin Meng ◽

Yong Wu ◽

...

Keyword(s):

Direct Observation ◽

Electron Attachment ◽

Planetary Atmosphere ◽

Interstellar Space ◽

Dissociative Electron Attachment ◽

Circumstellar Envelopes ◽

Vibrational States ◽

Cyanide Anion ◽

Exceptional Stability ◽

Electronic Ground

AbstractThe cyanide anion (CN−) has been identified in cometary coma, interstellar medium, planetary atmosphere and circumstellar envelopes, but its origin and abundance are still disputed. An isolated CN− is stabilized in the vibrational states up to ν = 17 of the electronic ground-state 1Σ+, but it is not thought to survive in the electronic or vibrational states above the electron autodetachment threshold, namely, in superexcited states. Here we report the direct observation of long-lived CN− yields of the dissociative electron attachment to cyanogen bromide (BrCN), and confirm that some of the CN− yields are distributed in the superexcited vibrational states ν ≥ 18 (1Σ+) or the superexcited electronic states 3Σ+ and 3Π. The triplet state can be accessed directly in the impulsive dissociation of BrCN− or by an intersystem transition from the superexcited vibrational states of CN−. The exceptional stability of CN− in the superexcited states profoundly influences its abundance and is potentially related to the production of other compounds in interstellar space.

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Nitrogen-containing aromatic compounds: quantitative analysis using gas chromatography with nitrogen phosphorus detector

Applied Petrochemical Research ◽

10.1007/s13203-021-00265-z ◽

2021 ◽

Author(s):

Yuan Rao ◽

Arno de Klerk

Keyword(s):

Gas Chromatography ◽

Quantitative Analysis ◽

Aromatic Compounds ◽

Process Development ◽

Complex Mixtures ◽

Response Factors ◽

Cyanide Anion ◽

Nitrogen Phosphorus Detector ◽

Assurance Process ◽

Nitrogen Containing Compounds

AbstractThe nitrogen-containing aromatic compounds found in the petrochemical industry are varied and extend beyond classes such as the anilines, pyrroles and pyridines. Quantification of these nitrogen-containing compounds that may occur in complex mixtures has practical application for quality assurance, process development and the evaluation of conversion processes. Selective detection of nitrogen-containing species in complex mixtures is possible by making use of gas chromatography coupled with a nitrogen phosphorous detector (GC-NPD), which is also called a thermionic detector. Despite the linearity of the NPD response to individual nitrogen-containing compounds, the response factor is different for different compounds and even isomers of the same species. Quantitative analysis using an NPD requires species-specific calibration. The reason for the sensitivity of the NPD to structure is related to the ease of forming the cyano-radical that is ionized to the cyanide anion, which is detected. The operation of the NPD was related to the processes of pyrolysis and subsequent ionization. It was possible to offer plausible explanations for differences in response factors for isomers based on pyrolysis chemistry. Due to this relationship, the NPD response can in the same way be used to provide information of practical relevance beyond its analytical value and a few possible applications were outlined.

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