Ion chemistry of 1H-1,2,3-triazole

A combination of experimental methods, photoelectron-imaging spectroscopy, flowing afterglow-photoelectron spectroscopy and the flowing afterglow-selected ion flow tube technique, and electronic structure calculations at the B3LYP/6-311++G(d,p) level of density functional theory (DFT) have been employed to study the mechanism of the reaction of the hydroxide ion (HO-) with 1H-1,2,3-triazole. Four different product ion species have been identified experimentally, and the DFT calculations suggest that deprotonation by HO- at all sites of the triazole takes place to yield these products. Deprotonation of 1H-1,2,3-triazole at the N1-H site gives the major product ion, the 1,2,3-triazolide ion. The 335 nm photoelectron-imaging spectrum of the ion has been measured. The electron affinity (EA) of the 1,2,3-triazolyl radical has been determined to be 3.447 +/- 0.004 eV. This EA and the gas-phase acidity of 2H-1,2,3-triazole are combined in a negative ion thermochemical cycle to determine the N-H bond dissociation energy of 2H-1,2,3-triazole to be 112.2 +/- 0.6 kcal mol-1. The 363.8 nm photoelectron spectroscopic measurements have identified the other three product ions. Deprotonation of 1H-1,2,3-triazole at the C5 position initiates fragmentation of the ring structure to yield a minor product, the ketenimine anion. Another minor product, the iminodiazomethyl anion, is generated by deprotonation of 1H-1,2,3-triazole at the C4 position, followed by N1-N2 bond fission. Formation of the other minor product, the 2H-1,2,3-triazol-4-ide ion, can be rationalized by initial deprotonation of 1H-1,2,3-triazole at the N1-H site and subsequent proton exchanges within the ion-molecule complex. The EA of the 2H-1,2,3-triazol-4-yl radical is 1.865 +/- 0.004 eV.     

Promotion of proton conduction in polymer electrolyte membranes by 1H-1,2,3-triazole

We report 1H-1,2,3-triazole as an active group to dramatically enhance proton conduction in a polymer electrolyte membrane (PEM). The conductivities of a poly(4-vinyl-1H-1,2,3-triazole) membrane without any acidic dopants are about 105 times greater than those of poly(4-vinylimidazole) in dry air at 50-150 degrees C. Polymers with groups promoting proton conduction attached to the backbone have great potential to offer excellent mechanical properties and long-term stability. Further, 1H-1,2,3-triazole and PEMs containing 1H-1,2,3-triazole are stable in a wide potential range, implying excellent electrochemical stability under fuel cell operating conditions.     

新型多氮化合物1,1＇-偶氮-1,2,3-三唑的合成与性能研究

以1-氨基-1,2,3-三唑（1）为原料,经二氯异氰尿酸钠（SDCI）氧化偶联合成了具有稳定N8结构（8个氮原子直接相连）和光致变色特性的新型多氮化合物1,1＇-偶氮-1,2,3-三唑（2）,通过IR,Raman,1H NMR,13C NMR,MS,元素分析等手段对其进行了表征;分离出了偶合反应副产物1H-1,2,3-...     

Quantum chemical study of the tautomerism, geometry, and electronic structure of 1,2,3- and 1,2,4-triazoles

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 chemical 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.Prof. Asen Zlatarov University, 8010 Burgas, Bulgaria. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 645–651, May, 1998.     

Trimethylsilyl-directed 1,3-dipolar cycloaddition reactions in the solid-phase synthesis of 1,2,3-triazoles

[reaction: see text] A regioselective method for the preparation of 1,5-trisubstituted 1H-1,2,3-triazoles via a 1,3-dipolar cycloaddition of 1-trimethylsilylacetylenes with organoazides is described. Immobilization of the azide on REM resin and subsequent cycloaddition afforded a 2 x 2 x 4 x 3 membered 1,5-disubstituted 1H-1,2,3-triazole library with an average purified yield of 68%.     

含1,2,3-三氮唑结构的1,5-苯并硫氮杂[艹卓]的合成及其抑真菌活性

设计合成了三类含1,2,3-三氮唑结构的1,5-苯并硫氮杂[艹卓]化合物3-(1H-1,2,3-三氮唑)-4-芳基-2,5-二氢-1,5-苯并硫氮杂[艹卓](5a^5f)、3-(2H-1,2,3-三氮唑)-4-芳基-2,3-二氢-1,5-苯并硫氮杂[艹卓](6a^6f)和3-(1H-1,2,3-三氮唑)-4-芳基-2,3,4,5-四氢-1,5-苯并硫氮杂[艹卓](7a^7f).研究了中间体及目标产物的合成条件,分离出其中两个副产物并进行了结构确定.目标产物的抑真菌活性测试表明,化合物5a^5f对真菌具有良好的抑制作用,对新生隐球菌的抑制效果尤为突出.初步抑真菌构效关系研究表明, 1H-1,2,3-三氮唑环和C=C双键是化合物5a^5f抑真菌活性的关键官能团.     

Synthesis and reactions of thioamides of 5-amino-2-aryl-2H-1,2,3-triazole-4-carboxylic acid

A method has been developed for obtaining thioamides of 5-amino-2-aryl-2H-1,2,3-triazole-4-carboxylic acid. Their heterocyclization reactions with bifunctional reagents has been studied. New heterocyclic polycyclic ensembles have been synthesized containing a 1,2,3-triazole fragment, a thiazole, and a residue of the natural alkaloid cytisine.     

Metal salts of the 4,5-dicyano-2H-1,2,3-triazole anion ([C4N5]-)

Diaminomaleodinitrile was reacted at low temperatures with in situ generated nitrous acid to form 4,5-dicyano-2H-1,2,3-triazole (1) in yields above 90%. Crystalline 1 was then reacted with one equivalent of a suitable alkali or alkaline earth metal base (typically a hydroxide or a carbonate) in a polar solvent to form the corresponding alkali and alkaline earth metal salts of 4,5-dicyano-2H-1,2,3-triazole (compounds 2-9). The thermal stability of the metal salts 2-9 was assessed by differential scanning calorimetry, which showed excellent thermal stabilities up to above 350 °C. Due to the energetic character of triazole-based salts, initial safety testing was used to assess the sensitivity of compounds 2-9 towards impact, friction, electrostatic discharge and fast heating. These results revealed very low sensitivities towards all four stimuli. Additionally, compounds 2-9 were characterized by mass spectrometry, elemental analysis, infrared and Raman spectroscopy and ((1)H, (13)C and (14)N) NMR spectroscopy. We also determined the solid state structure of the 4,5-dicyano-2H-1,2,3-triazole anion of one of the alkali metal salts (4: Monoclinic, P2(1)/c, a = 9.389(1) ?, b = 10.603(1) ?, c = 6.924(1) ?, β = 102.75(1)° and V = 1036.58(3) ?(3)) and one of the alkaline earth metal salts (6: Monoclinic, P2(1)/c, a = 9.243(1) ?, b = 15.828(2) ?, c = 6.463(1) ?, β = 90.23(1)° and V = 945.5(2) ?(3)). Furthermore, we noted the hydrolysis of one of the cyano groups of the 4,5-dicyano-2H-1,2,3-triazole anion in the strontium salt 8 to form the 5-cyano-2H-1,2,3-triazole-4-carboxylic acid derivative 8b, as confirmed by X-ray studies (8b: Monoclinic, P2(1)/n, a = 6.950(1) ?, b = 17.769(1) ?, c = 13.858(1) ?, β = 92.98(1)° and V = 1709.1(1) ?(3)). Lastly, we computed the NBO and Mülliken charges for the anion of compounds 2-9 and those of the anion of compound 8b.     

Dimeric assemblies from 1,2,3-triazole-appended Zn(II) porphyrins with control of NH-tautomerism in 1,2,3-triazole

Cu(I)-catalyzed 1,3-dipolar cycloaddition of meso-ethynyl Zn(II) porphyrin with benzyl azide efficiently provides meso-1-benzyl-1H-1,2,3-triazolyl Zn(II) porphyrin, which assembles to form a slipped cofacial dimer by the complementary coordination of the triazole nitrogen atom at the 3-position to the zinc center of a second porphyrin moiety both in the solid and solution states. Removal of the benzyl protection and introduction of a 2-ethoxycarbonylphenyl moiety greatly stabilize the dimeric assembly through an additional hydrogen bonding interaction between the NH proton of 2H-1,2,3-triazole and the carbonyl oxygen.     

Palladium(II) and platinum(II) complexes of bidentate 2-pyridyl-1,2,3-triazole “click” ligands: Synthesis,properties and X-ray structures

The synthesis and characterization of palladium(II) and platinum(II) complexes of isomeric bidentate 2-pyridyl-1,2,3-triazole “click” ligands is reported. The complexes have been fully characterized by elemental analysis, HRESI-MS, IR, UV–Vis, ¹H and ¹³C NMR spectroscopy. Additionally, the molecular structures of the Pd(II) and Pt(II) complexes of the 2-[(4-phenyl-1H-1,2,3-triazol-1-yl)methyl]pyridine ligand are confirmed by X-ray crystallography. Solution studies indicate the 2-(1-benzyl-1H-1,2,3-triazol-4-yl)pyridine ligand forms more stable complexes with Pd(II) and Pt(II) than the isomeric 2-[(4-phenyl-1H-1,2,3-triazol-1-yl)methyl]pyridine ligand.     

超声辐射下含1,2,3-三唑噻唑烷酮衍生物的合成

采用超声辐射法,以2-苯基-1,2,3-三唑-4-甲酰肼为原料,合成了3-(2-苯基-1,2,3-三唑-4-基)-5H-4-氧代噻唑[2,3-c].1,2,4-三唑,再与各种芳香醛进行Knoevenagel缩合反应,合成了一系列噻唑烷酮衍生物.所有目标化合物结构经元素分析,IR,1H NMR确证.     

Synthesis of 1,2,3-triazole nucleosides via the acid-catalyzed fusion procedure

The acid-catalyzed fusion of methyl 1,2,3-triazole-4-carboxylate, 4-cyano-1,2,3-triazole, and 4-nitro-1,2,3-triazole with an acylated ribofuranose provided the corresponding 2-β-D-ribo-furanosyl-4-substituted-1,2,3-triazoles along with the isomeric 1-β-D-ribofuranosyl-4-substituted-1,2,3-triazoles. The structures of these nucleosides were assigned on the basis of their nmr spectra. The synthesis of 2-β-D-ribofuranosyl-1,2,3-triazole-4-carboxamide from both the corresponding methyl ester and cyano nucleosides is described. The cyano nucleosides were utilized to prepare 2-β-D-ribofuranosyl-1,2,3-triazole-4-thiocarboxa?ide and 1-β-D-ribofuranosyl-1,2,3-triazole-4-thiocarboxamide. Reduction of the 4-nitro-1,2,3-triazole nucleosides provided 4-amino-2-β-D-ribofuranosyl-1,2,3-triazole and the isomeric 4-amino-1-β-D-ribofuranosyl-1,2,3-triazole. The acid-catalyzed fusion procedure with 1,2,3-triazole afforded 1-β-D-ribofuranosyl-1,2,3-triazole and 2-β-D-ribofuranosyl-1,2,3-triazole.     

新型四阳离子型1,2,3-三唑鎓环蕃的合成

以间苯二酚为原料,经5步反应制得中间体4,4′-［4,6-双(己氧基)-1,3亚苯基］双{1-［4-(叠氮甲基)苯基］-1H-1,2,3-三氮唑}(6); 6与1,5-二乙炔基-1,4-二(己氧基)苯在高度稀释的条件下经Click反应环合制得1,2,3-三唑环蕃(7); 7与三甲基氧鎓四氟硼酸盐反应合成了全甲基化的新型1,2,3-三唑鎓环蕃,其结构经¹H NMR, ¹³C NMR和HR-ESI-MS表征。     

Design synthesis and biological evaluation of 3-substituted triazole derivatives

Based on the active site of lanosterol 14α-demethylase of azole antifungal agents,sixteen 1-(1H-1,2,4-triazole-1-yl)- 2-(2,4- difluorophenyl)-3-(N-n-butyl-N-1-substitutedbenzyl-4-methylene-1H-1,2,3-triazole)-2-propanols have been designed,synthesized and evaluated as antifungal agents.Results of preliminary antifungal tests against eight human pathogenic fungi in vitro showed that some of the compounds exhibited excellent activities with broad spectrum.     

Synthesis of derivatives of 5-amino-4-acyl-1,2,3-triazole, 8-azapurine,and 1,2,3-triazolo[4,5-b]pyridin-7-one using N,N-acetals of acylketenes and tosylazide

By reaction of N,N-acetals of acylketenes with tosylazide there were synthesized 5-amino-4-acyl-1,2,3-triazoles substituted at the endo(N¹)- or exocyclic nitrogen atom. Triazoles containing a free NH₂ group were used in the synthesis of the corresponding 8-azapurines and 4-acetyl-5-benzoylamino-1,2,3-triazole afforded 2-methyl-2H,4H-1,2,3-triazolo[4,5-b]pyridin-7-one.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1392–1397, June, 1990.     

Unprecedented (3,10)-connected 2-D metal-organic framework constructed from octanuclear cobalt(II) clusters and a new bifunctional ligand

A metal-organic framework with the highest connectivity of 2-D topology was first assembled from an octacobalt(II) cluster as a 10-connected node and a new bifunctional ligand 1-(3,5-dicarboxy-phenyl)-4-phenyl-1H-1,2,3-triazole as a 3-connected node as well as "double bridge" linkers.     

Anhydrous proton conductivities of squaric acid derivatives

In this communication, we introduce squaric acid derivatives as anhydrous proton conductors. We report the synthesis, characterization and proton conductivities of four squaric acid derivatives. The anhydrous proton conductivity of one of the derivatives was 2.3 × 10(-3) S cm(-1) at 110 °C, comparable to the conductivity of molten 1H-1,2,3-triazole or 1H-imidazole.     

Coupled cluster,B2PLYP and M06-2X investigation of the thermochemistry of five-membered nitrogen containing heterocycles,furan, and thiophene

Herein, the thermochemical properties of five-membered rings heterocycles were studied employing the CCSD(T) methodology 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 \Updelta \textH_{\textf, 2 9 8}^\texto \Updelta {\text{H}}_{{{\text{f}}, 2 9 8}}^{\text{o}} , computed at the CCSD(T) level, is 0.5 kcal/mol with respect to the experimental 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 \Updelta \textH_{\textf, 2 9 8}^\texto \Updelta {\text{H}}_{{{\text{f}}, 2 9 8}}^{\text{o}} : 62.6, 59.2, 85.0, 54.2, 77.7, and 107.5 kcal/mol, respectively. For thiophene, we revisit our previous result and propose a value of 26.0 kcal/mol. The theoretical 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.     

Synthesis of 5-functionalized-1,2,3-triazoles via a one-pot aerobic oxidative coupling reaction of alkynes and azicles

In this paper, an efficient synthesis of 5-alkynyl-1,2,3-triazoles through a one-pot aerobic oxidative coupling reaction of various alkynes and azides has been developed. Further derivatization of 5-alkynyl-1,2,3-triazoles readily yielded 5-carbonyl-1,2,3-triazoles, 5-carboxylic-1,2,3-triazole, 5-hydroxyalkyl-1,2,3-triazoles and 5-quinoxaline-1,2,3-triazole, which provided an entry into structurally diverse 5-functionalized-1,2,3-triazoles.     

Synthesis of 5-functionalized-1,2,3-triazoles via a one-pot aerobic oxidative coupling reaction of alkynes and azides

In this paper, an efficient synthesis of 5-alkynyl-1,2,3-triazoles through a one-pot aerobic oxidative coupling reaction of various alkynes and azides has been developed. Further derivatization of 5-alkynyl-1,2,3-triazoles readily yielded 5-carbonyl-1,2,3-triazoles, 5-carboxylic-1,2,3-triazole, 5-hydroxyalkyl-1,2,3-triazoles and 5-quinoxaline-1,2,3-triazole, which provided an entry into structurally diverse 5-functionalized-1,2,3-triazoles.