Category: 63598-71-0

Ritchie, James P. published the artcileStructures and energies of the tautomers and conjugate bases of some 1,2,4-triazolones, Recommanded Product: 4H-1,2,4-Triazole, the publication is Journal of Organic Chemistry (1989), 54(15), 3553-60, database is CAplus.

MO calculations at the AM1, 3-21G//3-21G, and 6-31G^*//3-21G levels were performed for several possible tautomers of 1,2,4-triazol-5-one and 3-nitro-1,2,4-triazol-5-one. Calculations were also performed at the AM1, 3-21G//3-21G, and 6-31+G//3-21G levels for some conjugate bases of these compounds The results show the 1H,4H tautomer to be most stable. 5-Hydroxy-1H-1,2,4-triazole and 3-nitro-5-hydroxy-1H-1,2,4-triazole are found to lie 9.4 and 7.5 kcal/mol, resp., higher in energy than the corresponding 1H,4H isomer. The calculations may overestimate this relative energy by perhaps 1-3 kcal/mol. The calculations also predict deprotonation is most likely at N-4 of the lowest energy triazolone, but nearly equally likely at N-1 and N-4 for the corresponding nitrotriazolone (although the N-4 position is slightly favored). The substitution effects of the nitro group were examined by comparing calculated geometries, relative energies, and electrostatic potentials of the triazolones and nitrotriazolones. Electronegativity effects predominate for the neutral compounds In the conjugate bases, a significant contribution from resonance participation of the nitro group was found. Problems in using the electrostatic potential to predict the site of electrophilic substitution in the triazolone are discussed.

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 C2H3N3, Recommanded Product: 4H-1,2,4-Triazole.

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

Jano, Issam published the artcileComparison between approximate methods for calculating ionization potentials and the use of σ-ionization potentials as a measure of relative basicity of azoles, Safety of 4H-1,2,4-Triazole, the publication is Journal of Physical Chemistry (1991), 95(20), 7694-9, database is CAplus.

Approx. methods for calculating valence-shell ionization energies are compared at the INDO level of approximation These methods are based on Koopmans, many-body Green function, and perturbation theories. The method based on perturbation theory is presented for the first time in this work. Some characteristics and limitations of these methods are pointed out. In addition, a linear relationship between the σ-ionization potentials of azole mols. and their protonation energies is found and analyzed on the basis of Mulliken’s resonance structure theory of the charge-transfer complexes. It is concluded that the polarization, charge-transfer, and exchange energies are responsible for the stabilization of the protonated systems, whereas the electrostatic energy plays a rather small and destabilizing role.

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, Safety of 4H-1,2,4-Triazole.

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

Fabian, Walter M. F. published the artcileTautomerism in five-membered nitrogen heterocycles. A test of the reliability of semiempirical (AM1, PM3, MNDO) quantum chemical methods, Related Products of triazoles, the publication is Zeitschrift fuer Naturforschung, A: Physical Sciences (1990), 45(11-12), 1328-34, database is CAplus.

The reliability of three popular semiempirical quantum chem. methods (AM1, PM3, MNDO) for the treatment of tautomeric equilibrium is tested in a series of five-membered nitrogen heterocycles. The known flaw of MNDO to overest. the stability of compounds with two or more adjacent pyridine-like lone pairs is also present in AM1 and to a somewhat lesser extent in PM3. Tautomeric species differing in the number of adjacent pyridine-like lone pairs, thus, cannot be adequately treated by these semiempirical methods. Both AM1 as well as PM3, however, represent major improvements over MNDO in the case of lactam-lactim tautomerism. The stability of N-oxides as compared to N-hydroxy tautomers seems to be overestimated by the PM3 method. All three semiempirical methods yield quite reliable ionization potentials and dipole moments.

Zeitschrift fuer Naturforschung, A: Physical Sciences 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, Related Products of triazoles.

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

Denis, Pablo A. published the artcileCoupled cluster, B2PLYP and M06-2X investigation of the thermochemistry of five-membered nitrogen containing heterocycles, furan, and thiophene, Recommanded Product: 4H-1,2,4-Triazole, the publication is Theoretical Chemistry Accounts (2011), 129(2), 219-227, database is CAplus.

Herein, the thermochem. properties of five-membered rings heterocycles were studied employing the CCSD(T) methodol. coupled with the correlation consistent basis sets and including corrections for relativistic and core-valence effects as well as anharmonicities of the potentials. For pyrrole, furan, imidazole, pyrazole, 1H-1,2,4-triazole, and 1H-tetrazole, the mean absolute deviation (MAD) of the ΔH_f,298⁰, computed at the CCSD(T) level, is 0.5 kcal/mol with respect to the exptl. values. In the case of 1H-1,2,3-triazole, 2H-1,2,3-triazole, 4H-1,2,3-triazole, 4H-1,2,4-triazole, 2H-tetrazole, and pentazole, we propose the following : 62.6, 59.2, 85.0, 54.2, 77.7, and 107.5 kcal/mol, resp. For thiophene, we revisit our previous result and propose a value of 26.0 kcal/mol. The theor. estimations were used to study the performance of the M06-2X and B2PLYP functionals. Also, the convergence toward the complete basis set limit (CBS) was analyzed. M06-2X did not show a smooth convergence toward the CBS limit. Particularly, for the cc-pVTZ and cc-pVQZ basis sets, some problems were detected. Yet, along the cc-pVQZ, cc-pV5Z, and cc-pV6Z basis sets, the TAE smoothly decreased. The diminution of the TAE upon increase in basis set was not expected because the opposite behavior is more frequently observed The MAD of the total atomization energies determined at the M06-2X level was 0.42 kcal/mol, with respect to the CCSD(T) results. In the case of the double hybrid B2PLYP functional, a smooth convergence toward the CBS limit was detected, even though the performance seriously degradated when the basis set was increased. At the CBS limit, the MAD with respect to the CCSD(T) TAEs was 8.26 kcal/mol.

Theoretical Chemistry Accounts 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

Bird, C. W. published the artcileA new aromaticity index and its application to five-membered ring heterocycles, Recommanded Product: 4H-1,2,4-Triazole, the publication is Tetrahedron (1985), 41(7), 1409-14, database is CAplus.

A new index of aromatic character has been devised based upon a statistical evaluation of the deviations in peripheral bond orders. The latter can be derived readily from exptl. determined bond lengths. The utility of this index is exemplified by its application to five-membered ring heterocycles and their mesoionic derivatives

Tetrahedron 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

Bean, Gerritt P. published the artcileApplication of Natural Bond Orbital Analysis and Natural Resonance Theory to Delocalization and Aromaticity in Five-Membered Heteroaromatic Compounds, Product Details of C2H3N3, the publication is Journal of Organic Chemistry (1998), 63(8), 2497-2506, database is CAplus and MEDLINE.

The various measures of delocalization in all of the five-membered nitrogen and oxygen heteroaromatic compounds (azoles and oxoles) were obtained from MO calculations at the HF/6-31G* level and the application of natural bond orbital anal. and natural resonance theory. The hydrogen transfer and aromatic energies of these compounds were also calculated These were compared to the relative ranking of aromaticity reported by Katritzky from a principal component anal. of other measures of aromaticity. It was concluded that the extent of the transfer of electron d. from the p_z orbital of the heteroatom to the rest of the π system is the best measure of delocalization and “aromaticity” of these compounds This indicated that all of the oxoles are less delocalized than any of the azoles because the electronegativity of the oxygen atom prevents the interaction of its lone pair of electrons with the π system. For this reason the range of delocalization in the oxoles is also much narrower. The degree of delocalization in the π system is the result of the geometry imposed by the σ structure, which in turn is defined by the identity and arrangement of the atoms of the ring.

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 C2H3N3, Product Details of C2H3N3.

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

Aihara, Jun-ichi published the artcileDimensionality of aromaticity, Application In Synthesis of 63598-71-0, the publication is Bulletin of the Chemical Society of Japan (2008), 81(2), 241-247, database is CAplus.

Aromaticity was viewed as multidimensional, because different scales of aromaticity sometimes make different predictions as to the aromaticity of a polycyclic π-system. Graph theory of aromaticity and ring-current diamagnetism enables us to interpret magnetic scales of aromaticity in terms of aromatic stabilization energy (ASE). The authors have now no reason to regard any magnetic scale of aromaticity as a scale orthogonal to the energetic ones. Aromaticity is one-dimensional in this sense and should in principle be described in terms of ASE. Other scales of aromaticity, such as geometric ones, must likewise reflect ASE to varying extents, although it is not easy to interpret them anal. in energetic terms.

Bulletin of the Chemical Society of Japan 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, Application In Synthesis of 63598-71-0.

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

Makarskii, V. V. published the artcileQuantum-chemical analysis of tautomerism of 1,2,4-triazole and its amino and diamino derivatives, SDS of cas: 63598-71-0, the publication is Khimiya Geterotsiklicheskikh Soedinenii (1977), 540-5, database is CAplus.

The heats of formation and dipole moments of I, II, and their 3-amino and 3,5-diamino derivatives were calculated by CNDO/2 and MINDO/2 methods. The unsym. triazole rings were favored over the sym. rings, and exocyclic amino tautomers were favored over imino tautomers.

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, SDS of cas: 63598-71-0.

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

Lau, Justin Kai-Chi published the artcileAbsolute potassium cation affinities (PCAs) in the gas phase, Recommanded Product: 4H-1,2,4-Triazole, the publication is Chemistry – A European Journal (2003), 9(14), 3383-3396, database is CAplus and MEDLINE.

The potassium cation affinities (PCAs) of 136 ligands (20 classes) in the gas phase were established by hybrid d. functional theory calculations (B3-LYP with the 6-311 + G(3df,2p) basis set). For these 136 ligands, 70 exptl. values are available for comparison. Except for five specific PCA values-those of phenylalanine, cytosine, guanine, adenine (kinetic-method measurement), and Me₂SO (by high-pressure mass spectrometric equilibrium measurement)-our theor. estimates and the exptl. affinities are in excellent agreement (mean absolute deviation (MAD) of 4.5 kJ mol^-1). Comparisons with previously reported theor. PCAs are also made. The effect of substituents on the modes of binding and the PCAs of unsubstituted parent ligands are discussed. Linear relations between Li⁺/Na⁺ and K⁺ affinities suggest that for the wide range of ligands studied here, the nature of binding between the cations and a given ligand is similar, and this allows the estimation of PCAs from known Li⁺ and/or Na⁺ affinities. Furthermore, empirical equations relating the PCAs of ligands with their dipole moments, polarizabilities (or mol. weights), and the number of binding sites were established. Such equations offer a simple method for estimating the PCAs of ligands not included in the present study.

Chemistry – A European Journal 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

Cox, James R. published the artcileTautomerism of 1,2,3- and 1,2,4-triazole in the gas phase and in aqueous solution: a combined ab initio quantum mechanics and free energy perturbation study, Recommanded Product: 4H-1,2,4-Triazole, the publication is Journal of Physical Chemistry (1990), 94(14), 5499-501, database is CAplus.

The energy differences between the tautomers of 1,2,3- and 1,2,4-triazole have been estimated at the 6-31G^**(MP2)//3-21G level including zero-point effects. The results confirm that only a single tautomer of each isomer is expected to be observed in the gas phase. In aqueous solution the free energy separation of tautomers is considerably reduced and has been estimated by use of the free energy perturbation method. These calculations agree with the exptl. findings that for 1,2,3-triazole both tautomers are observed in a polar solvent, whereas for 1,2,4-triazole the concentration of the rare tautomer is still extremely low.

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, Recommanded Product: 4H-1,2,4-Triazole.

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