New chromogens of the ferroin type-VIII Some di- and trisubstituted 1,2,4-triazines, 3-substituted-9H-indeno[1,2-e]-1,2,4-triazin-9-ones, and di- and trisubstituted 1,2,4-triazolines

Thirty-six new ferroin compounds have been investigated as possible chelation regents for the calorimetric detection and determination of trace amounts of iron(II), copper(I), and cobalt(II). Spectral data, solution conditions favourable for chelate formation, and other data are reported. The results reveal that incorporation of triazoline heterocycles in ferroin chromophore groupings generally leads to poor chromogenic properties, except with respect to cobalt. Triazine groups, however, can give rise to superior properties. The most sensitive iron(II) chromogen of the ferroin type found to date and a promising new cobalt chromogen are described.     

Some new chromogens for iron, cobalt, and copper Substituted hydrazidines and 1,2,4-triazines containing the ferroin group

The spectral characteristics and solution conditions requisite for formation of the iron(II), cobalt(II), and copper(I) complexes of some newly synthesised compounds containing the ferroin functional grouping have been determined. These properties are useful for evaluation of the possible analytical effectiveness of the compounds as spectrophotometric reagents for the determination of iron, cobalt, and copper.     

New chromogens of the ferroin type-VI: some derivatives of 1- and 3-cyanoisoquinoline and substituted 2-cyanopyridines

The chromogenic reactions with iron(II), copper(I) and cobalt(II) of 32 recently synthesized pyridazines, triazines, tetrazines and certain other compounds containing the ferroin grouping have been examined spectrophotometrically. Some interesting examples were found of steric and donor-atom selectivities in chelation of iron by ligands containing several ferroin groups. Of the various chromogens studied, the pyridyl and isoquinolyl derivatives of phenyl or pyridyl substituted 1,2,4-triazine show the most promising analytical utility.     

New chromogens of the ferroin type-V Pyridylpyrimidines, bidiazines and other substituted derivatives of diazines

Spectrophotometric studies of the reactions of iron(II), copper(I) and cobalt(II) with 33 new compounds have demonstrated that the chromogenic properties of diazyl groups are inferior to those of triazyl or pyridyl groups when incorporated into the ferroin chromophore group. The metal complexes of the diazyl derivatives are less stable than those of the corresponding pyridyl and triazyl derivatives. Conditional formation constants of the iron(II) chelates of some representative diazyl derivatives indicate that pyridazyl groups impart greater stabilities than pyrimidyl or pyrazyl groups. Five of the new chromogens have structures that suggest they can chelate iron(II) without steric hindrance, either as bidentate or as terdenate ligands. Although the terdentate mode would ordinarily be expected, two of the five were found to act preferably as bidentate ligands.     

1,2,4-Triazines. 3. halogen-sulfur exchange in the preparation of 5,6-disubstituted-1,2,4-triazines

The preparation and displacement reactions of 3-amino-5,6-bismethylthio-1,2,4-triazine ( 3 ) are described.     

Phospha-s-triazines. IV. Degradation studies of 1-diarylphospha-3,5-bis(perfluoroaliphatic)-2,4,6-triazines and 1,3,-bis(diarylphospha)-5-perfluoroaliphatic-2,4,6-triazines

Thermal and thermal oxidative stability evaluations were performed on mono- and diphospha-s-triazines at 235 and 316°C using sealed Pyrex ampoules. The specific compounds studied were: 1-diphenylphospa-3,5-bis(perfluoro-n-heptyl)-2,4,6-triazine, 1-diphenylphospha-3,5-bis(perfluoro-alkylether)-2,4,6-triazines, their respective pentafluorophenyl analogues, 1,3-bis(diphenylphospha)-5-perfluoro-n-heptyl-2,4,6-triazine and 1,3-bis(diphenylphospha)-5-perfluoroalkylether-2,4,6-triazine. All the compounds wherein phenyl groups were present on the phosphorous exhibited good thermal stability up to 316°C; the analogous pentafluorophenyl substituted materials were degraded extensively at these temperatures. The oxidative stability of both the mono- and diphospha-s-triazines was excellent at 235°C, but at 316°C some degradation was observed. This was more pronounced in compounds containing the perfluoroalkyl moiety on carbon than in the perfluoroalkylether substituted members of the series.     

The synthesis of 4-substituted-4H-1,2,4-triazole-3-thiols and 3-methylthio-4-substituted-4H,2,4-triazoles

The synthesis of 4-substituted-4H-1,2,4-triazole-3-thiols and 3-methylthio-4-substituted-4H-1,2,4-triazoles by the condensation of 4-substituted-3-thiosemicarbazides with dimethylformamide dimethyl acetal or dimethylacetamide dimethyl acetal is described. A discussion of the mechanistic pathway is included.     

A Facile synthesis of 3-alkylthio-(or arylthio-)pyridines and 3,5-bis(alkylthio)pyridines

3-Alkylthio- (or 3-arylthio-)pyridines and 3,5-bis(alkylthio)pyridine can be conveniently prepared by the reaction of 3-thiocyanato- or 3,5-bis(thiocyanato)pyridines with tri-n-butylphosphine in the presence of alcohol.     

Synthesis and nmr study of 7-aryl-1,2,4-triazolo-[1,5-a]-1, 3,5-triazines

The reactionof N-(1,2,4)-triazol-5-yl)amidines with ethyl orthoformate is a convenient method for the fusion of a triazine ring to the triazole ring. An NMR study showed that the heterocyclic compounds obtained are 7-aryl-1,2,4-triazolo-[1,5- a]-1,3,5-triazines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2386–2388, October, 1989.     

Studies with polyfunctionally substituted heteroaromatics: New routes for the synthesis of polyfunctionally substituted pyridines and 1,2,4-triazolo[1,5-a]pyridines

The 1-substituted ethylidenemalononitriles 1a–c condensed with triethyl orthoformate in refluxing acetic anhydride to yield the dienes 2a–c . On the other hand, a mixture of N,N-dimethylformamide and triethyl orthoformate condensed with 1a–d to yield the N,N-dimethylaminopentadienonitriles 2d–g . The pentadienonitriles 2d–g were also formed from the reaction of 1a–d with dimethylformamide dimethylacetal in refluxing acetic acid. When compounds 1a–c were treated with dimethylformamide dimethylacetal in refluxing p-xylene, a mixture of 3 , 4 and 2e–g was formed. The reaction of 2a , b with hydrazine hydrate afforded the N-amino-2-iminopyridines 5a , b . These were converted into the triazolo[1,5-a]pyridines 8a–d on treatment with benzoyl chloride and with dimethylformamide dimethylacetal. On the other hand, the reaction of 2c with hydrazine hydrate afforded the pyrazolo[3,4-b]pyridine 7c . Treatment of 2a , c or 2e , g with cyanoethanoic hydrazide afforded the N-(cyanoacetamido)pyridines 9a , b . The dienes 2d , f , g afforded the pyridones 11a–c on treatment with acetic acid and hydrochloric acid mixture. Compounds 11b , c were also formed on treatment of 2b , c with acetic acid hydrochloric acid mixture. The reaction of 2d , g with ethanolic sodium ethoxide gave the ethoxypyridines 13a , b .     

Mesoionic dimethyl derivatives of some 1,2,4-triazinones. The course of the reaction of 3,5-dimethoxy, 3-methoxy-5-methylthio, 5-methoxy-3- methylthio and 3,5-bis(methylthio)-1,2,4-triazine with methyl iodide

Treatment of 3,5-dimethoxy-1,2,4-triazine ( 1a ) with methyl iodide was found to give depending on the reaction time triazinium iodide 2a , triaziniumolates 4a and 6a as well as methoxytriazinones 7a and 8a . Thermolysis of 2a gave triaziniumolates 4a and 6a . Reaction of 2a , 4a or methoxytriazinone 9a with methyl iodide in acetonitrile yielded as the sole product 6a . Reaction of 3-methoxy-5-methylthio-1,2,4-tri-azine (1b ) with methyl iodide gave triazinium iodide 2b and methylthio triazinone 7b . Hydrolysis of 2a,b afforded 4a . Reaction of 5-methoxy-3-methylthio-1,2,4-triazine ( 1c ) with methyl iodide gave triazinium iodide 2c , triaziniumolate 4b , triazinium iodide 5b and triazinone 8b . Hydrolysis of 2c yielded 4b and its thermolysis gave a mixture of 4b and 5b . Reaction of 2c , 4b and triazinone 9b with methyl iodide afforded 5b . Treatment of 3,5-bis(methylthio)-1,2,4-triazine ( 1d ) with methyl iodide was found to give a mixture of N1 and N2 methiodides 2d and 3d which gave on hydrolysis 4b and 8b , respectively. Methylation of 6-methyl derivatives 1c-g gave analogous results, however the proportions of N1 methylated products were lower and the reaction rates higher in comparison to their respective lower homologues 1a,c,d . The structures of the mesoionic dimethyl derivatives were assigned from uv, ir, ¹H nmr and electron impact mass spectra. The structural assignments were eventually confirmed by quantum chemical calculations of net charge distributions, bond lengths and ipso angles of the C5?O bonds.     

Synthesis, Crystal Structure and Property of a Series of Supramolecular Polymers Based on Novel 3,5-Dimethyl- 2,6-bis（3-（pyrid-2-yl）-1,2,4-triazolyl）pyridine Ligand

Solvothermal reactions of 3,5-dimethyl-2,6-bis(3-(pyrid-2-yl)-1,2,4-triazolyl) pyridine (L), 1,4-benzendicarboxylic acid (H2bdc), and transitional metal cations of MII (M = Mn, Co, Cd) in the presence of oxalic acid (H2ox) afford three novel supramolecular polymers (CPs), namely, {[M2(ox)(L)2][bdc][M2(Hox)2(OH)2(H2O)4].3H2O}n (M=Mn for 1, Co for 2, Cd for 3). Single-crystal X-ray diffraction analysis reveals that complexes 1-3 are isostructural and the 3D supramolecular structure was connected through non-covalent interactions. With the help of H2ox, the L ligands cheated with center atoms forming a butterfly [M2(ox)(L)2]2+ building block. The bdc2- ligand linked with the unprecedented [M2(Hox)2(OH)2(H2O)4] units through strong O-H…O hydrogen bonds forming a zigzag chain, which are further connected through π…π interactions between L and bdc2- ligands to form a 3D supramolecular structure. Moreover, elemental analyses, IR, thermogravimetric, PXRD and luminescence have been investigated.     

3,5-dibromo-1-(1,1-dioxothietanyl-3)-1,2,4-triazole, new reagent for preparation of substituted thietane 1,1-dioxides

A new reagent, 3,5-dibromo-1-(1,1-dioxothietanyl-3)-1,2,4-triazole, was introduced for the synthesis of 3-substituted thietane 1,1-dioxides that were treated with sodium alcoholates and phenolates to prepare 3-alkoxyand 3-aryloxythietane 1,1-dioxides.     

Infrared and Raman spectra of 3,5-diamino-6-(o-C6H4X)-1,2,4-triazines [X = F,Cl, Br,CH3

Raman and infrared spectra of four substituted 3,5-diamino-6-(ortho-substituted phenyl)-1,2,4-triazines, having ortho-fluoro, -chloro, -bromo and -methyl groups on the phenyl ring, are reported and discussed. Bands due to substituent sensitive phenyl vibrations are observed in both the Raman and infrared spectra. The Raman spectra of all four compounds have strong bands near 770 and 1330 cm(-1) which are assigned to the ring breathing vibration of the 1,2,4-triazine ring and an asymmetric triazine C-NH2 stretching vibration, respectively. A medium/strong band near 800 cm(-1) in the infrared spectra is attributed to an out-of-plane bending vibration of the substituted 1,2,4-triazine ring.     

Reactions of sulfur monochloride with some aromatic aldehyde semicarbazones and thiosemicarbazones: New syntheses of substituted 2,4-dihydro-1,2,4-triazol-3-ones, 2,4-dihydro-1,2,4-triazole-3-thiones and 2-amino-1,3,4-oxadiazoles

Treatment of various substituted semicarbazones of aromatic aldehydes with sulfur monochloride yields the corresponding substituted 2,4-dihydro-1,2,4-triazol-3-ones. With thiosemicarbazones, the products are derivatives either of the 2-amino-1,3,4 thiadiazole or of the 2,4-dihydro-1,2,4-triazole-3-thione depending on the experimental conditions.     

Pyridine-Type Complexes of Transition-Metal Halides XIV. Part III. Complexes with 2,4-, 2,6-, 3,4- and 3,5-lutidines

Compounds obtained by a solid–gas phase reactions between copper(II) chloride and bromide and 2,4-, 2,6- 3,4- and 3,5-lutidines were studied using thermogravimetry, far-infrared, electronic spectroscopy and X-ray diffraction. The results were compared with the corresponding data for the similar compounds with methylpyridines and 2,4,6-collidine. A special attention was paid to the host-guest phenomenon, a new structural feature of transition-metal halide complexes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis and electrochemical properties of 2,6-bis（6-aryl-[1,2,4]- triazolo[3,4-b][1,3,4]-thiadiazole-3-yl）pyridines

By the condensation of 2,6-bis（4-amino-5-mercapto-[1,2,4]-triazoles-2）pyridine with aromatic acid in the presence of phosphorus oxychloride. Compounds of 2,6-bis（6-aryl-[1,2,4]-triazolo[3,4-b][1,3,4]-thiadiazole-3-yl）pyridines were synthesized. Their structures were confirmed by IR, ^1H NMR spectroscopies and elemental analysis. Their electrochemical behavior and cyclic voltammogram also were be studied. The results showed that they have high ionization potentials and good affinity.