Tag: M.W=50-100

Tipping, Anthony E. published the artcileStructure, Basicity, and Thermodynamic Properties of 3,5-Bis(trifluoromethyl)-1,2,4-triazole with Regard to 1,2,4-Triazole: The Trifluoromethylation Effect, SDS of cas: 63598-71-0, the publication is Journal of Organic Chemistry (1994), 59(5), 1039-46, database is CAplus.

Thermodn. properties (enthalpies of sublimation, gas-phase basicity) of 3,5-bis(trifluoromethyl)-1,2,4-triazole have been measured. These properties are discussed in the larger framework of two other triazoles, the parent compound and 3(5)-(trifluoromethyl)-1,2,4-triazole, thanks to ab initio calculations at the MP2/6-31G^*//6-31G^* level of accuracy. The calculations provide (i) an excellent description of the vibrational frequencies of 1H-1,2,4-triazole; (ii) a geometry for this compound more consistent with the microwave results; (iii) a description of the trifluoromethyl group as a substituent in the azole series; (i.v.) an excellent accord with the exptl. proton affinity, and (v) an understanding of the interesting properties of the title compound

Journal of Organic Chemistry published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C5H5ClIN, SDS of cas: 63598-71-0.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Davarski, K. A. published the artcileQuantum chemical study of the tautomerism, geometry, and electronic structure of 1,2,3- and 1,2,4-triazoles, HPLC of Formula: 63598-71-0, the publication is Chemistry of Heterocyclic Compounds (New York)(Translation of Khimiya Geterotsiklicheskikh Soedinenii) (1998), 34(5), 568-574, database is CAplus.

A systematic study was carried out on the tautomerism and geometry of 1,2,3- and 1,2,4-triazoles using the semiempirical AM1, PM3, MNDO, and Mindo/3 methods and nonempirical quantum chem. methods taking account of electronic correlation (MP2). The semiempirical methods were found to give incorrect results for the tautomerism of these triazoles, while the nonempirical methods correctly give the energy relationships and show enhanced stability for 2H-1,2,3- and 1H-1,2,4-triazoles attributed to the interaction of the unpaired electron pairs of the adjacent nitrogen atoms. Optimization of the geometry of 2H-1,2,3-triazole by the nonempirical methods showed that bases such as 6-21G and more expanded bases must be used and that electronic correlation should be taken into account. The use of updated calculation methods in the case of 1H-1,2,4-triazole did not give improved results.

Chemistry of Heterocyclic Compounds (New York)(Translation of Khimiya Geterotsiklicheskikh Soedinenii) published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, HPLC of Formula: 63598-71-0.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Hoste, S. published the artcileESCA spectra of pyrazole-copper complexes, Quality Control of 63598-71-0, the publication is Conference on Coordination Chemistry (1987), 103-8, database is CAplus.

The N 1s, C 1s, and Cu 2p ESCA spectra are presented for a series of 7 Cu(II)-pyrazole-NCO complexes. The core level binding energies in these complexes, together with those in the free ligand trimethylpyrazole are discussed in terms of at. charges derived from partial orbital electronegativity and in terms of the relaxation potential model.

Conference on Coordination Chemistry published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, Quality Control of 63598-71-0.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Abu-Eittah, Rafie H. published the artcileMolecular-orbital treatment of some heterocycles with three hetero-atoms and their benzo-derivatives, Recommanded Product: 4H-1,2,4-Triazole, the publication is International Journal of Quantum Chemistry (1985), 28(6), 731-40, database is CAplus.

MO INDO procedures were carried out on the tautomers of 1,2,4-triazole and its benzo derivative as well as on 1,2,5-oxadiazole and its benzo derivative Calculations of the transition energy as well as the dipole moment helped to predict the predominant tautomer in an equilibrium mixture The correspondence between the calculated and observed data is satisfactory. The results of calculations indicated some differences in the electronic structures of the tautomers of a compound

International Journal of Quantum Chemistry published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, Recommanded Product: 4H-1,2,4-Triazole.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Ogretir, Cemil published the artcileQuantum chemical studies on tautomerism and basicity behavior of some 1,2,4-triazole derivatives, HPLC of Formula: 63598-71-0, the publication is Turkish Journal of Chemistry (2010), 34(6), 977-988, database is CAplus.

The acidity constants, relative stabilities, and tautomeric equilibrium constants of some 1,2,4-triazole derivatives were determined using the d. functional theory (DFT) with the B3LYP method and 6-311G(d,p) basis set. The integral equation formalism version of the polarizable continuum model (IEFPCM) was used in the calculations of the aqueous phase. The calculated tautomeric equilibrium and relative stabilities values revealed that the 4H-1,2,4 triazole form for all studied mols. was favored over the 1H-1,2,4 triazole form. Protonation processes indicated the predominance of the 1H-1,2,4 triazole form over the 2H-1,2,4 triazole form. The correlation attempt between the exptl. and the calculated acidity constants, pK_a values, revealed that they are quite close to the exptl. values and they correlate well with a regression of around unity (R² = 1).

Turkish Journal of Chemistry published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, HPLC of Formula: 63598-71-0.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Carlsen, Per published the artcileThermal rearrangement of 4-alkyl-1,2,4-triazoles. Rearrangements in the crystalline state, Recommanded Product: 4H-1,2,4-Triazole, the publication is Molecules [Electronic Publication] (1996), 242-250, database is CAplus.

A review and symposium lecture on the thermolyses of 4-alkyl-1,2,4-triazoles with 16 references They were observed to rearrange at 200-350° to the corresponding 1-alkylated triazoles. When substituted in the 4-position with aryl or vinylic substituents, the triazoles were inert to thermolysis, contrary to what was observed for the 4-alkyl- and 4-allyl-substituted systems. The mechanisms for the reactions were elucidated, e.g., by studies of substituent effects and by kinetic measurements in solution as well as for the neat samples. Reactions in solution were slow. The rearrangements in melts of the neat triazoles readily proceeded to the products, and were proposed to take place via a series of nucleophilic displacement steps. X-ray crystallog. measurements of selected structures showed that the interat. distances and angles between the relevant atoms in these structures to a large degree resembled the geometry expected for the S_N2-type transition states proposed for the rearrangement mechanism. Thus, thermolyses of a series of triazole structures at temperatures below their m.ps., confirmed that rearrangements actually did take place. The “kinetics” of the reactions in the crystalline state were investigated, and rate constants and thermodn. data were correlated with the structural characteristics of the crystals.

Molecules [Electronic Publication] published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, Recommanded Product: 4H-1,2,4-Triazole.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Vidal-Vidal, Angel published the artcileCO₂ Complexes with Five-Membered Heterocycles: Structure, Topology, and Spectroscopic Characterization, HPLC of Formula: 63598-71-0, the publication is Journal of Physical Chemistry A (2017), 121(47), 9118-9130, database is CAplus and MEDLINE.

In a 1st step toward the rational design of macrocyclic structures optimized for CO₂ capture, we systematically explored the potential of 30 five-membered aromatic heterocycles to establish coordinating complexes with this pollutant. The interactions between the 2 moieties were studied in several orientations, and the obtained complexes were analyzed in terms of electron d. and vibrational fingerprint. The former is an aid to provide an in-depth knowledge of the interaction, whereas the latter should help to select structural motifs that have not only good complexation properties but also diagnostic spectroscopic signals.

Journal of Physical Chemistry A published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C18H34N4O5S, HPLC of Formula: 63598-71-0.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Del Bene, Janet E. published the artcileComplexes of CO₂ with the azoles: tetrel bonds,hydrogen bonds and other secondary interactions, Category: triazoles, the publication is Molecules (2018), 23(4), 906/1-906/14, database is CAplus and MEDLINE.

Ab initio MP2/aug’-cc-pVTZ calculations have been performed to investigate the complexes of CO₂ with the azoles pyrrole, pyrazole, imidazole, 1,2,3- and 1,2,4-triazole, tetrazole and pentazole. Three types of complexes have been found on the CO₂:azole potential surfaces. These include ten complexes stabilized by tetrel bonds that have the azole mol. in the symmetry plane of the complex; seven tetrel-bonded complexes in which the CO₂ mol. is perpendicular to the symmetry plane; and four hydrogen-bonded complexes. Eight of the planar complexes are stabilized by N_x···C_tetrel bonds and by a secondary interaction involving an adjacent Ny-H bond and an O atom of CO₂. The seven perpendicular CO₂:azole complexes form between CO₂ and two adjacent N atoms ofthe ring, both of which are electron-pair donors. In three of the four hydrogen-bonded complexes,the proton-donor Nz-H bond of the ring is bonded to two C-H bonds, thereby precluding the planar and perpendicular complexes. The fourth hydrogen-bonded complex forms with the strongest acidpentazole. Binding energies, charge-transfer energies and changes in CO₂ stretching and bending frequencies upon complex formation provide consistent descriptions of these complexes. Coupling constants across tetrel bonds are negligibly small, but ^2hJ(Ny-C) across Nz-H···C hydrogen bonds arelarger and increase as the number of N atoms in the ring increases.

Molecules published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, Category: triazoles.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Del Valle, J. C. published the artcileA theoretical study of the acidity of nitrogen heterocycles, Formula: C2H3N3, the publication is Journal of Molecular Structure: THEOCHEM (1992), 481-91, database is CAplus.

INDO and AM1 calculations of C-H and N-H deprotonation (acidity) of 20 nitrogen heterocycles were performed. Acidity is explained by taking into account lone pair repulsion, aza, and annelation effects. The AM1 method has to be corrected by adding 9 kcal mol^-1 for each adjacent lone pair-lone pair interaction.

Journal of Molecular Structure: THEOCHEM published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, Formula: C2H3N3.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics

Mo, O. published the artcileProtonation energies and tautomerism of azoles. Basis set effects, HPLC of Formula: 63598-71-0, the publication is Journal of Physical Chemistry (1986), 90(22), 5597-604, database is CAplus.

The structure, protonation energies, tautomerism, and vertical ionization potentials of several azoles are examined by ab initio calculations using different basis sets ranging from minimal to split valence plus polarization. Minimal basis tends to overestimate all N-N and C-N lengths. Though, in general, 3-21G geometries are close to 6-31G structures, the former basis does not always correct the deficiencies of minimal basis. In general, 6-31G structures agree with the exptl. ones. Azoles with more than one basic N atom protonate preferentially on imidazolic rather than on pyrazolic type N atoms. Minimal basis significantly overestimates absolute protonation energies, but the deviations observed for relative protonation energies are not always of the same sign. Both 3-21G and 6-31G absolute protonation energies are almost equal and much smaller than those obtained at the minimal basis level. The inclusion of polarization functions in the basis (6-31G^*//6-31G calculations) leads to a further decrease in absolute protonation energies which depends on the degree of anisotropy of the charge distribution of the center which undergoes protonation. The relative stabilities of the tautomers change with the basis set. These changes are particularly important for triazolium and tetrazolium cations, as well as for pyrazole and imidazole. For 1,2,4-triazoles, tetrazoles, and 1H-pentazole Koopman’s theorem predicts the wrong ionization potential.

Journal of Physical Chemistry published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, HPLC of Formula: 63598-71-0.

Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics