593-75-9Relevant academic research and scientific papers
Microwave spectrum and geometry of the methyl isocyanide-argon complex
Blanco, Susana,Lister, David G.,Legon,Rego, Christopher A.
, p. 1287 - 1290 (1997)
The rotational spectrum of a complex formed between methyl isocyanide and argon has been observed using pulsed-nozzle, Fourier-transform microwave spectroscopy. The spectrum and geometry of the complex are very similar to those found for CH3CN...Ar (R. S. Ford et al., J. Chem. Phys., 1991, 94, 5306). The complex is T-shaped, with the argon atom located 3.64 A from the centre of mass of the methyl isocyanide molecule. There appears to be almost free internal rotation of the methyl isocyanide molecule about its symmetry axis in the complex.
Tunneling Model for Hydrogen Abstraction Reactions in Low-Temperature Solids. Applications to Reactions in Alcohol Glasses and Acetonitrile Crysals
Roy, Robert J. Le,Murai, Hisao,Williams, Ffrancon
, p. 2325 - 2334 (1980)
A simple and internally consistent quantitative model for hydrogen-abstraction reactions in low-temperature solids, which implicitly incorporates zero point energy effects which allow for finite reaction rates at T=0 K, is derived and applied to new measurements of H-abstraction rate constants by methyl radicals in methanol and ethanol glasses at T=13-99 K and in acetonitrile and methyl isocyanide crystals at 69-128 K.Nonlinear least-squares fits of the model to the experimental data yield effective one-dimensional barriers to reaction whose heights are virtually independent of the analytic form used for the potential energy barrier, and are somewhat larger than the activation energies measured for the corresponding reactions in the gas phase.This model predicts that values of the isotopic rate constant ratio kH/KD will be larger than 1012 at T=0 K.
Isomers of C2H4N+ and the Proton Affinities of CH3CN and CH3NC
Knight, J. S.,Freeman, C. G.,McEwan, M. J.
, p. 1404 - 1408 (1986)
The relative proton affinities of CH3CN (acetonitrile) and CH3NC (methyl isocyanide were determined by using the Selected Ion Flow Tube technique.Two distinct species were observed for the C2H4N+ ion: one produced from CH3CN and one from CH3NC.The two C2H4N+ isomers were readily distinguished in the flow tube by their different reactivity.The association product, C2H4N+, of the ion-molecule reaction between CH3+ and HCN was shown to be present in both isomeric forms in the ratio 85percent protonated acetonitrile and 15percent protonated methyl isocyanide.
Single photon ionization of methyl isocyanide and the subsequent unimolecular decomposition of its cation: Experiment and theory
Bellili,Gouid,Gazeau,Bénilan,Fray,Guillemin,Hochlaf,Schwell
, p. 26017 - 26026 (2019)
Methyl isocyanide, CH3NC, is a key compound in astrochemistry and astrobiology. A combined theoretical and experimental investigation of the single photon ionization of gas phase methyl isocyanide and its fragmentation pathways is presented. Vacuum ultraviolet (VUV) synchrotron radiation based experiments are used to measure the threshold photoelectron photoion coincidence (TPEPICO) spectra between 10.6 and 15.5 eV. This allowed us to experimentally determine the adiabatic ionization energy (AIE) and fragment ion appearance energies (AE) of gas-phase methyl isocyanide. Its AIE has been measured with a precision never achieved before. It is found to be AIEexp = 11.263 ± 0.005 eV. We observe a vibrational progression upon ionization corresponding to the population of vibrational levels of the ground state of the methyl isocyanide cation. In addition, four fragment ion appearance energies (AEs) were measured to be AE (m/z 40) = 12.80 ± 0.05 eV, AE (m/z 39) = 13.70 ± 0.05, AE (m/z 15) = 13.90 ± 0.05 eV, AE (m/z 14) 13.85 ± 0.05 eV, respectively. In order to interpret the experimental data, we performed state-of-the-art computations using the explicitly correlated coupled cluster approach. We also considered the zero-point vibrational energy (ZPVE), core-valence (CV) and scalar relativistic (SR) effects. The results of theoretical calculations of the AIE and AEs are in excellent agreement with the experimental findings allowing for assignment of the fragmentations to the loss of neutral H, H2, CN and HCN upon ionization of CH3NC. The computations show that in addition to the obvious bond breakings, some of the corresponding ionic fragments result from rearrangements-upon photon absorption-either before or after electron ejection.
Potentially prebiotic activation chemistry compatible with nonenzymatic RNA copying
Zhang, Stephanie J.,Duzdevich, Daniel,Szostak, Jack W.
, p. 14810 - 14813 (2020)
The nonenzymatic replication of ribonucleic acid (RNA) may have enabled the propagation of genetic information during the origin of life. RNA copying can be initiated in the laboratory with chemically activated nucleotides, but continued copying requires a source of chemical energy for in situ nucleotide activation. Recent work has illuminated a potentially prebiotic cyanosulfidic chemistry that activates nucleotides, but its application to nonenzymatic RNA copying had not been demonstrated. Here, we report a novel pathway that activates RNA nucleotides in a manner compatible with template-directed nonenzymatic copying. We show that this pathway, which we refer to as bridge-forming activation, selectively yields the reactive imidazolium-bridged dinucleotide intermediate required for copying. Our results will enable more realistic simulations of RNA propagation based on continuous in situ nucleotide activation.
Pressure Dependence of the Laser-Initiated Isomerization of Methyl Isocyanide
Shultz, M. J.,Rock, Elizabeth J.,Tricca, Robert E.,Yam, Loretta M.
, p. 5157 - 5162 (1984)
The infrared laser-induced isomerization of methyl isocyanide has been investigated and found to exhibit a marked pressure dependence; i.e., for a given set of conditions, there exists a sharp threshold pressure above which there is massive isomerization.In the subthreshold region, it has been determined that the yield depends exponentially on the pressure for a multimode beam.Since other authors have suggested that this laser-induced reaction is a thermal explosion, we have also carried out a numerical simulation of this system as a thermal explosion.Both the experimental and theoretical results are presented, and the results show that the thermal explosion model does not fit the experimental data.
A Light-Releasable Potentially Prebiotic Nucleotide Activating Agent
Mariani, Angelica,Russell, David A.,Javelle, Thomas,Sutherland, John D.
supporting information, p. 8657 - 8661 (2018/07/15)
Investigations into the chemical origin of life have recently benefitted from a holistic approach in which possible atmospheric, organic, and inorganic systems chemistries are taken into consideration. In this way, we now report that a selective phosphate activating agent, namely methyl isocyanide, could plausibly have been produced from simple prebiotic feedstocks. We show that methyl isocyanide drives the conversion of nucleoside monophosphates to phosphorimidazolides under potentially prebiotic conditions and in excellent yields for the first time. Importantly, this chemistry allows for repeated reactivation cycles, a property long sought in nonenzymatic oligomerization studies. Further, as the isocyanide is released upon irradiation, the possibility of spatially and temporally controlled activation chemistry is thus raised.
Synthesis and structure–activity relationship of α-keto amides as enterovirus 71 3C protease inhibitors
Zeng, Debin,Ma, Yuying,Zhang, Rui,Nie, Quandeng,Cui, Zhengjie,Wang, Yaxin,Shang, Luqing,Yin, Zheng
supporting information, p. 1762 - 1766 (2016/12/22)
α-Keto amide derivatives as enterovirus 71 (EV71) 3C protease (3Cpro) inhibitors have been synthesized and assayed for their biochemical and antiviral activities. structure–activity relationship (SAR) study indicated that small moieties were primarily tolerated at P1' and the introduction of para-fluoro benzyl at P2 notably improved the potency of inhibitor. Inhibitors 8v, 8w and 8x exhibited satisfactory activity (IC50= 1.32 ± 0.26 μM, 1.88 ± 0.35 μM and 1.52 ± 0.31 μM, respectively) and favorable CC50values (CC50> 100 μM). α-Keto amide may represent a good choice as a warhead for EV71 3Cproinhibitor.
2,3-Dihydroimidazol-2-ylidene
Maier, Guenther,Endres, Joerg
, p. 1517 - 1520 (2007/10/03)
Irradiation of imidazole-2-carboxylic acid (3) - matrix-isolated in argon at 10 K - with a wavelength of 254 nm leads to decarboxylation and the formation of a complex between 2,3-dihydroimidazol-2-ylidene and carbon dioxide (1·CO2). Upon irradiation of 2,3-dihydroimidazol-2-ylidene (1) with λ = 254, 193, and 185 nm no imidazole can be detected. On the other hand flash vacuum pyrolysis of imidazole-2-carboxylic acid (3) produces imidazole and carbon dioxide. 2,3-Dihydroimidazol-2-ylidene (1) - the possible intermediate - cannot be trapped under these conditions.
Internal excitation in the products of nucleophilic substitution from the dissociation of metastable ion complexes
Graul, Susan T.,Carpenter, Catherine J.,Bushnell, John E.,Van Koppen, Petra A. M.,Bowers, Michael T.
, p. 6785 - 6796 (2007/10/03)
The relative kinetic energy distributions for the products of the dissociation of four metastable gasphase ion clusters have been analyzed by means of ion kinetic energy spectroscopy, and the results modeled using statistical phase space theory. The systems studied represent reaction intermediates in bimolecular nucleophilic substitutions (S(N)2). These studies build on previous investigations that demonstrated vibrational excitation in the products of the substitution reactions of halide ions with methyl halides. The present studies explore the effects of molecular structure, reaction exothermicity, and nucleophile and leaving group variation. The experimental kinetic energy distributions are compared with theoretical distributions calculated for statistical partitioning of energy among internal modes and relative kinetic energy of the products. In each reaction, the calculated distributions agree with the experimental distributions only if a significant fraction of the energy released in the exothermic reactions is assumed to be unavailable for randomization in the dissociation. The results suggest that the products of these S(N)2 reactions are internally excited.
