Thermal analysis of disazo pigments

The differential-thermal and thermogravimetric analysis of eight derivatives of 1,4-bis-(5-hydroxy-7-sulpho-2naphthyl)-benzenediamide showed that these compounds have a marked exothermic effect, with maxima in the temperature range 280–330°C. The derivative of 4-nitroaniline-2-sulphonic acid were found to undergo a blast-like decomposition in the temperature intervals 255–265°C and 285–290°C, which is reflected by large steps in their TG curves.The thermal analysis of disazo pigments permits determination of their applicability at higher temperatures.

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Zusammenfassung Die DT- und TG- Analyse von acht Derivaten von 1,4-bis-(5-Hydroxy-7-sulpho-2naphthyl)-benzoldiamid zeigte, dass diese Verbindungen mit einem Maximum im Temperaturbereich 280–330°C einen eindeutigen exothermen Effekt aufweisen. Derivate mit 4-Nitroanilin-2-sulfonsäure zeigen eine explosionsartige Zersetzung im Temperaturintervall 255–265°C und 285–290°C, was sich in den TG-Kurven in einer großen Stufe wiederspiegelt.Die Thermoanalyse von Bisazopigmenten ermöglicht eine Ermittlung ihrer Anwendbarkeit für höhere Temperaturen.

     

The structure of xanthalin

Conclusions From the roots ofXanthogalum purpurascens growing in the Transcaucasus, we have isolated a new coumarin, C₂₄H₂₆O₇ with mp 111–113°C, [] _D ²⁰ –164.2° (c 0.97; ethanol) which we have called xanthalin. On the basis of the NMR spectrum it has been established that xanthalin is 3, 4-diangeloyl-2, 2-dimethyl-3, 4-dihydropyrano-5, 6:6, 7-coumarin.Khimiya Prirodnykh Soedinenii, Vol. 4, No. 5, pp. 280–283, 1968     

Reaction of heterocyclic betaines. Synthesis of a new heterocyclic system

A new condensed heterocyclic system, viz., 1,3,7,9-tetra-oxo-2,8-diphenyl-6-formylpyrimido [3,4-a]pyrimido[4,5-dloxazine, was synthesized, and its electronic and PMR spectra were recorded. Factors that affect the orientation of nucleophilic substitution in betaines of the pyrimidine series with aliphatic amines are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 993–995, July, 1980.     

Convenient synthesis of 5′-methyl-2′-desoxyuridines

A convenient method has been developed for the synthesis of 5-methyl-2-desoxyuridines. Chlorination of 5-O-benzoyl-5-methyluridines with a mixture of Ph₃P and CCl₄ in DMF affords the 2-desoxy-2-chloro-derivatives, which are then reduced with tributyltin hydride. The crystalline 5-O-benzoyl-5-methyl-2-desoxyuridines were obtained in overall yields of 40–60%. In a similar way, 5-O-benzoyluridine has given 5-O-benzoyl-2-desoxyuridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 246–248, February, 1989.     

Synthesis of heteroannular mercury derivatives of acetoxy- and methoxyferrocene

Conclusions The synthesis of 1,1-(acetoxy)chloromercuryferrocene, di-1(1-acetoxyferrocenyl)mercury, 1,1-(methoxy)chloromercuryferrocene, and di-1-(1-methoxyferrocenyl)mercury from ferrocenylboric acids was described.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2574–2575, November, 1967.     

Synthesis and characterization of some methyl complexes of palladium(II). Part 2(1)

Summary Dichloro complexes of Pd^II, [Pd(L–L)Cl₂], where L–L=1-(thiomethyl)-2-(diphenylarsino)ethane (S–As) or 1-(thiomethyl)-2-(diphenylphosphino)ethane (S–P) andtrans-[PdL₂Cl₂], where L=diphenyl(2-phenylethyl)-phosphine (PE), diphenyl(1-naphthyl)phosphine (PN) orN-methyl-2-thiophenealdimine (SN), have been prepared and characterized. The reactions of these complexes with MeLi were investigated. The dimethyl complexes [Pd(L–L)Me₂] (L–L=S–As, S–P) and [Pd(PE)Me₂] were isolated and characterized. Reaction of [Pd(L–L)Me₂] (L–L=S–As, S–P) with HCl affords the monomethyl derivatives [Pd(L–L)Me(Cl)]. In contrast to the Pt analogues, [Pd(L–L)Me₂] and [Pd(L–L)Me(Cl)] are relatively less stable than [Pt(L–L)Me₂] and [Pt(L–L)Me(Cl)].     

Soluble polysaccharides of Rhodotorula flava

Conclusions 1. Xanthalin has been shown to have the structure of 2, 2-dimethyl-3, 4,-diangeloyloxy-3, 4-dihydropyrano-5, 6:6, 7-coumarin on the basis of the preparation of a number of derivatives and cleavage products.2. The following products of the alkaline hydrolysis of xanthalin have been isolated and characterized for the first time: (±)-3, 4-dihydroxy-3, 4-dihydroxanthyletin (isokhellactone), C₁₄H₁₄O₅, with mp 213–215° C and (–)-trans-3-hydroxy-4-methoxy-3, 4-dihydroxanthyletin (isomethylkhellactone, C₁₅H₁₆O₅, with mp 136.5–138° C and [] _D ²⁰ –47.7 (ethanol).Khimiya Prirodnykh Soedinenii, Vol. 6, No. 1, pp. 14–19, 1970     

Structure of tetraphenylarsonium tricyano- 2,2′,6′,2′′-terpyridylferrate(II), AsPh4[FeII(terpy)(CN)3]; and kinetics of oxidation of the complex anion by peroxodisulfate in water and in binary aqueous mixtures

The structure of the title compound has been determined by X-ray crystallography. The octahedral arrangement of ligands about the iron(II) centre is somewhat distorted, with the axial NC–Fe–CN bond angle being 174.3(4)°. The oxidation of the tricyano-2,2,6,2- terpyridylferrate(II) anion by the peroxodisulfate anion has been investigated in water and in binary aqueous mixtures. The reaction follows a second order rate law, with a second-order rate constant of 0.126± 0.001dm3mol–1s–1 at 295.2K. The enthalpy and entropy of activation in water are 51.3±1.8kJmol–1 and –89±5JK–1mol–1 respectively. The rate is retarded on addition of organic cosolvent. The transfer chemical potential of the initial state from water into mixed solvents has been determined from solubility measurements, and compared with the transfer potential of the transition state. Solvent effects on the reaction are discussed in terms of initial state versus transition state solvation.     

The structure of seselirin: A new chromone from the roots ofSeseli sessiliflorum

Conclusions From the roots ofSeseli sessiliflorum Schrenk a new chromone has been isolated for which the structure of 2,2-dimethyl-3-(3-methylthioacryloyloxy)-3,4-dihydropyrano-5,6:6,7-(5-hydroxy-2-methyl) chromone has been proposed. It is the first representative of this group of natural compounds containing sulfur.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 4, pp. 412–415, 1970     

Synthesis and structure of o-bis(2-fluoro-2,2-dinitroethyl)-nitromethyl ester of 2′-fluoro-2′, 2′-dinitroethyl-2″-fluoro-2″-nitroethylenecarboxime

Conclusions The product of conversion of O-bis(2-fluoro-2,2-dinitroethyl)nitromethylbis(2-fluoro-2,2-dinitroethyl)carboxime in methanol or ether is O-bis(2-fluoro-2,2-dinitroethyl)nitromethyl-2-fluoro-2,2-dinitroethyl-2'-fluoro-2-nitroethylenecarboxinie, the structure of which has been established by x-ray diffraction analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2019–2021, September, 1987.     

Isoflavones of the roots of Lupinus luteus

Summary On the basis of mass and IR spectra it has been established that the substance with mp 169°C known in the literature as the acetyl derivative of gossypetin 3,3,4,5,8-pentamethyl ether is in actual fact gossypetin hexamethyl ether.Thus, yet another case of the migration of a methoxy group from partially etherified compounds in an alkylationprocess has been described.Scientific-Research Institute of the Chemistry and Technology of Cotton Cellulose, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 170–172, March–April, 1972.     

Transformed steroids. 161. Reactivity of 17-spirooxetane-20-ketosteroids towards opening of the four-membered ring

Conclusions Replacement of the 20-oxo group in 17,21-epoxypregn-5-en-3-ol-20-one by the hydrazono-group affects the cleavage of the oxetane ring by thiocyanic acid, reaction occurring preferentially by introduction of^–NCS at C¹⁷ with consequent expansion of the four-membered ring to a six-membered ring with the formation of the [17; 21]-1,3-tetrahydrooxazine-2-thione.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1393–1396, June, 1987.     

Protonation and cyclization of 1,3-diarylpropynones in superacids

1,3-Diarylpropynones ArCCCOAr in superacids with H ₀ ranging from –20 to – 14 undergo protonation at the carbonyl oxygen atoms to give stable ArCCC(O⁺H)Ar ions or at the acetylenic C² atom with formation of reactive ArC⁺=CHCOAr species. The effects of the Ar and Ar substituents and reaction conditions on the intramolecular cyclization of ArC⁺=CHCOAr to 3-arylinden-1-ones are discussed.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 12, 2004, pp. 1819–1828.Original Russian Text Copyright © 2004 by Vasilev, Walspurger, Pale, Sommer, Haouas, Rudenko.     

Cobalt(II) and nickel(II) chloride and bromide complexes of 2-(2′-methyl-8′-quinolyl)benzoxazole and 2-(2′ or 4′-methyl 8′-quinolyl)benzimidazole

Summary Cobalt(II) and nickel(II) halide complexes of the ligands 2-(2-methyl-8-quinolyl)benzoxazole (mqbo), 2-(2-methyl8quinolyl)benzimidazole (mqbi) and 2-(4-methyl-8-quinolyl)benzimidazole (mqbi) were synthesized and characterized by analytical, thermogravimetric, conductivity and magnetic data, and i.r. and electronic spectra.The ligands are bidentate N-donors yielding complexes where the coordination geometry depends on the metal ion and steric hindrance. All the cobalt complexes have formula [CoL₂X₂] and distorted tetrahedral geometry. Different types of nickel compounds were obtained: i) complexes of formula NiLX₂ · n H₂O (or EtOH) (L = mqbo or mqbi; n=0–1.5) which arepseudo-tetrahedral or five-coordinate and ii) complexes NiL₂X₂ · n H₂O (L = mqbi, n=3 or 4) where the metal is bound to four nitrogen atoms and the overall coordination geometry is tetragonal. The structural changes occurring after removal of water or alcohol from the complexes are also reported.     

Synthesis of 9-diazo-4-azafluorenes

Stable diazo compounds of the azafluorene series, viz., 9-diazo-4-azafluorenone and 1,3-diphenyl-4-azafluorene, were obtained from 4-azafluorenone and 1,3-diphenyl-4-azafluorene tosylhydrazones. 1,2-Dicarbomethoxyspiro(4-azafluorene-9,3-cyclopropane) was obtained from 4-azafluorenone tosylhydrazone, and 4,5-dicarbomethoxyspiro(4-azafluorene-9,3-pyrazolenine) was obtained from 9-diazo-4-azafluorene. It is assumed that the product in the latter case is obtained as a result of reaction of a carbene, viz., 4-azafluorenylidene carbene, which is formed from 9-diazo-4-fluorene, with dimethyl acetylenedicarboxylate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 951–953, July, 1979.     

The effect of zinc(II) on the formation of 2,2′- and 2,3′-bipyridine complexes of [Ru2II(ttha)]2−(ttha6−=triethylenetetraminehexaacetate)

Ru2II(ttha)(H2O)2]2– (ttha6–= triethylene tetramine hexa-acetate), prepared by the reduction of the ruthenium(III) precursor, reacts with 2,2-bipyridine (2,2-bpy) in a multi-step fashion. The first 2,2-bpy equivalent (1:1) adds with bidentate chelation at one ruthenium(II) site as revealed by separate ruthenium(II)/(III) waves at 0.03 and 0.54V vs. n.h.e. A second equivalent of 2,2-bpy (1:2) is initially stored and retained as the [Zn(2,2-bpy)]2+ complex. Further addition of 2,2-bpy initiates coordination at the second ruthenium(II) site. [Ru2(ttha)-(2,2-bpy)(H2O)]2– forms a strong ion-pair with zinc(II) that is in rapid equilibrium with the Zn(H2O)62+/Zn(2,2-bpy)]2+ pool. The solubility of the ion-pair is low. The ion-pair exhibits a shifted ruthenium(II)/(III) wave at 0.60V. Higher amounts of 2,2-bpy recomplex the zinc(II), solubilizing the complex and returning the E1/2 value to 0.54V. Other ligands which either have a higher affinity for ruthenium(II) centres than for zinc(II) as bidentate donors (1,10-phenanthroline), or ligands that cannot form bidentate zinc(II) complexes [(2-methylpyrazine, 4,4-bipyridine (4,4-bpy), and 2,3-bipyridine (2,3-bpy)] do not exhibit the unusual competition by zinc(II). These ligands all add statistically to the ruthenium(II) centres forming 1:2 complexes with 1:2 stoichiometries. 1H-n.m.r. studies of the Ru(II)polyaminopolycarboxylate complexes [RuII(hedta)(H2O)]– complex, and [Ru2(ttha)(H2O)2]2– itself, reveal that substitution of 2,3-bpy at ruthenium(II) sites occurs with an initial kinetic split between the pyridyl rings of the 3- less-hindered and 2-more-hindered ring. A slower rearrangement occurs, producing the isomer of the more-hindered 2-substituted ring. A process is driven by forming a more -accepting system when ruthenium(II) binds to the 2-ring of 2,3-bpy. Understanding the unusual influence of zinc(II) on the substitution of 2,2-bpy with [Ru2(ttha)(H2O)2]2– clarifies the nature of the 1:1 complex – namely that the 2,2-bpy becomes bidentate at one ruthenium(II) centre rather than serving as a trans-bridging ligand between both ruthenium(II) centres within one [Ru2(ttha)]2– unit.     

BISPHENYLENECOSAN as highly selective Cs+ extraction agent

A new reagent for the highly selective extraction of cesium (e-1,7–2,2)4,8–8,4-(bis--o-phenylene)bisdicarbollidocobalt(1–)ate, [(C₂B₉H₉)₂(C₆H₄)₂Co]^–, abbreviated as BISPHECOSAN is described in this paper. The choice of organic solvent and solubilizer, dependence of distribution ratio of Cs⁺ on acidity and other parameters are studied. The extraction mechanism based on selective binding of Cs⁺ cation between two phenylene rings is presented and factors influencing the chemical stability of the reagent are determined.