Theoretical and matrix isolation FTIR studies of 3-amino-1,2,4-triazole and its isomers

UV-induced proton transfer in 3-amino-1,2,4-triazole

“…The structure, isomerization pathways and vibrational spectra of AT in the ground electronic state isolated in low-temperature argon matrix have been studied by Pagacz-Kostrzewa et al [30] The combination of FTIR spectroscopy and theoretical calculations led to the conclusion that AT existed in solid argon in two tautomeric forms: 1-AT and 2-AT and the results reported there form the background for the present experiment.…”

“…1). According to the previously reported computations (MP2 and B3LYP with 6-311 + +G(2d,2p) basis set) [30], as well as those used here (MP2 and B3LYPD3 with 6-311 + +G(3df,3pd) basis set) the ZPE corrected energy difference between these two tautomers falls into the 0.83-1.19 kcal mol À1 range with 1-AT being a global minimum. On the basis of the calculated relative Gibbs free energies at different levels of theory, it was estimated that the equilibrium gaseous mixture (at evaporation temperature, 333 K) before matrix deposition contains 76-83% of 1-AT and 24-17% of 2-AT.…”

“…2 (black traces). The two most stable 1-AT and 2-AT tautomers are present in both matrices [30]. Positions of the bands observed for 1-AT and 2-AT in argon and xenon matrices together with the wavenumbers predicted by calculations are given in Table S1 in Supplementary data.…”

“…our earlier paper for details [30]) the two most stable are amino forms 1-AT and 2-AT differing in a position of the annular H-atom that is attached either to N1 or N2 atom of the triazole ring (see Fig. 1).…”

Spectroscopy studies, X-ray diffraction and DFT, HF calculations of 4-allyl-5-(thiophen-2-ylmethyl)-2H-1,2,4-triazol-3(4H)-one

“…The literature concerning the 1,2,4-triazole is rich and the papers published cover such subjects as crystal structure determination [16][17][18], ab initio and DFT calculations on the tautomerism and protonation sites [19][20][21], vibrational characteristics and photochemical transformations [22][23][24][25] and thermal decomposition products [26,27]. Many reports have appeared on the synthesis and characterization of novel triazole containing organic [28,29] or metal coordination compounds [30,31] including spin-crossover materials [32,33].…”