The gas-phase rotational spectrum of (cyanomethylene)cyclopropane, (CH)C═CHCN, generated by a Wittig reaction between the hemiketal of cyclopropanone and (cyanomethylene)triphenylphosphorane, is presented for the first time. This small, highly polar nitrile is a cyclopropyl-containing structural isomer of pyridine. The rotational spectra of the ground state and two vibrationally excited states were observed, analyzed, and least-squares fit from 130 to 360 GHz. Over 3900 R-, P-, and Q-branch, ground-state rotational transitions were fit to low-error, partial octic, A- and S-reduced Hamiltonians, providing precise determinations of the spectroscopic constants. The two lowest-energy vibrationally excited states, ν and ν, form a Coriolis-coupled dyad displaying small - and -type resonances. Transitions for these two states were measured and least-squares fit to a two-state, partial octic, A-reduced Hamiltonian in the I representation with nine Coriolis-coupling terms (, , , , , , , , and ). The observation of many resonant transitions and nine nominal interstate transitions enabled a very accurate and precise energy difference between ν and ν to be determined: Δ = 29.8975453 (33) cm. The spectroscopic constants presented herein provide the foundation for future astronomical searches for (cyanomethylene)cyclopropane.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpca.1c03246 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Impact of Halide (Cl vs I) Identity on the Preferred Positioning of Substituents between Al and M (M = Co, Rh, Ir) in PAlP Pincer Complexes.
Organometallics
January 2025
Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77842, United States.
Protolysis of AlMe or AlEt with 2-diisopropylphosphinopyrrole () resulted in alane/bis(phosphine) pincer ligands containing two flanking phosphines and a central Al-Me (), Al-Et () unit. Reactions of with [(COD)MI] (COD = 1,5-cyclooctadiene; M = Rh or Ir) in the presence of pyridine produced pincer complexes ( and ) with M supported by the PAlP tridentate ligand, and pyridine, methyl, and iodide as monodentate ligands for Al or M. The analogous reaction of with [(COD)MI] and pyridine resulted in the formation of the analogous compounds and with hydride in place of methyl.
View Article and Find Full Text PDFAntimicrobial Activity of Naphthyridine Derivatives.
Pharmaceuticals (Basel)
December 2024
Department of Organic Chemistry and Pharmaceutical Technology, Faculty of Pharmacy, Wroclaw Medical University, 211A Borowska Str., 50-556 Wroclaw, Poland.
To combat the problem of the increasing drug resistance of microorganisms, it is necessary to constantly search for new medicinal substances that will demonstrate more effective mechanisms of action with a limited number of side effects. Naphthyridines are N-heterocyclic compounds containing a fused system of two pyridine rings, occurring in the form of six structural isomers with different positions of nitrogen atoms, which exhibit a wide spectrum of pharmacological activity, in particular antimicrobial properties. This review presents most of the literature data about the synthetic and natural naphthyridine derivatives that have been reported to possess antimicrobial activity.
View Article and Find Full Text PDFFrom Structure to Function: Analysis of the First Monomeric Pyridoxal-5'-Phosphate-Dependent Transaminase from the Bacterium .
Biomolecules
December 2024
Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071 Moscow, Russia.
The first monomeric pyridoxal-5'-phosphate (PLP)-dependent transaminase from a marine, aromatic-compound-degrading, sulfate-reducing bacterium Tol2, has been studied using structural, kinetic, and spectral methods. The monomeric organization of the transaminase was confirmed by both gel filtration and crystallography. The PLP-dependent transaminase is of the fold type IV and deaminates D-alanine and ()-phenylethylamine in half-reactions.
View Article and Find Full Text PDFReactivity of Imidazole- and Pyridine-Carboxaldehydes for Gem-Diol and Hemiacetal Generation: Theoretical and Experimental Insights.
ChemistryOpen
January 2025
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Department of Chemistry, Ciudad Autónoma de Buenos Aires, 1113, Argentina.
Gem-diols are defined as organic molecules carrying two hydroxyl groups at the same carbon atom, which is the result of the nucleophilic addition of water to a carbonyl group. In this work, the generation of the hydrated or hemiacetal forms using pyridine- and imidazole-carboxaldehyde isomers in different chemical environments was studied by Nuclear Magnetic Resonance (NMR) recorded in different media and combined with theoretical calculations. The change in the position of aldehyde group in either the pyridine or the imidazole ring had a clear effect in the course of the hydration/hemiacetal generation reaction, which was favored in protic solvents mainly in the presence of methanol.
View Article and Find Full Text PDFBBL enzymes exhibit enantiospecific preferences in the biosynthesis of pyridine alkaloids in Nicotiana tabacum L.
Phytochemistry
April 2025
Department of Crop and Soil Science, North Carolina State University, Raleigh, NC, USA. Electronic address:
Plant species can accumulate secondary metabolites in optically pure form or, occasionally, as enantiomeric mixtures. Interestingly, enantiomers of the same molecule can confer different biological activities. In tobacco (Nicotiana tabacum L.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!