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At first, 1,4-Bis(pyridinium bi-sulfonic acid)benzene dimethylsulfonate (BPBSBDM), as a new Brønsted acidic ionic liquid (BAIL), is efficiently synthesized and revealed utilizing FT-IR (Fourier-transform infrared spectroscopy), TGA (thermogravimetric analysis), 13C NMR, 1H NMR and Mass data. Subsequently, its catalytic activity was studied in preparing bis(pyrazolyl)methane derivatives through the one-pot multicomponent coupled domino reactions (MCDRs) among 1 mmol aldehydes (aryl, heteroaryl, or alkyl aldehydes), 2 mmol ethyl acetoacetate, and 2 mmol phenylhydrazine/hydrazine hydrate under optimal conditions (50 °C, solvent-free, and 4 mol% of BPBSBDM) in high yields (89–98%), and in short times (2–7 min). Our protocol has the advantages of reasonable turnover number (TON: 22.25 to 24.50) and turnover frequency (TOF: 3.17 to 12.25 min−1) values, high yields of products, non-metallic nature of the catalyst, short reaction times, eco-friendly and economy, easy recyclability and good reproducibility. In addition, three derivatives 8a, 9a and 10a were synthesized and fully identified for the first time. [ABSTRACT FROM AUTHOR]

In this research, a novel and efficient nanocatalyst, namely, palladium immobilized onto 1,4-bis(pyrid-4-yl)benzene grafted to n-propyl-functionalized Fe3O4@MCM-41 nanoparticles (PBPBPMF), was synthesized and introduced. Then, its catalytic activity was tested in the synthesis of bis(pyrazolyl)methane (14 examples, 90–97%, 9–25 min, solvent-free, 60 °C) and biphenyl (13 examples, 80–98%, 10–120 min, PEG-400, 70 °C) derivatives. Bis(pyrazolyl)methane derivatives were synthesized via a one-pot pseudo-five-component reaction of aldehydes, ethyl acetoacetate, and phenylhydrazine, and biphenyl derivatives were obtained by a Stille coupling reaction. Transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 sorption isotherms, vibrating sample magnetometer (VSM), inductively coupled plasma atomic emission spectrometer (ICP-OES), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and elemental mapping analyses were used to identify the catalyst. The PBPBPMF is a heterogeneous catalyst with several advantages, including a large specific surface area, ease of purification, and separation from the reaction mixture; furthermore, the nanocatalyst was recycled six times without appreciably altering its catalytic properties. [ABSTRACT FROM AUTHOR]

In this study, a new green method was developed for the synthesis of bis(indolyl)methane derivatives using electrochemical bisarylation reaction in deep eutectic solvents as a green alternative to traditional solvents and electrolytes. The effects of varying time, current, type of solvent and material of electrodes were all studied. The optimum reaction conditions involved the use of ethylene glycol/choline chloride with a ratio of 2:1 at 80 °C for 45 min. Graphite and platinum were used as cathode and anode, respectively. The newly developed method offered many advantages such as using mild reaction conditions, short reaction time and affording high product yields with a wide range of substituted aromatic aldehydes bearing electron donating or electron withdrawing substituents. In addition, the electrochemical method proved to be more effective than heating in deep eutectic solvents and afforded higher yields of products in shorter reaction time. The mechanism of the electrochemical reaction was proposed and confirmed using the cyclic voltammetry study. [ABSTRACT FROM AUTHOR]

An efficient one pot synthesis of various bis-coumarinyl methane derivatives was investigated by condensing a series of aldehydes with 4-hydroxy coumarin in the presence of Amberlyst 15 catalyst under refluxing conditions in ethanol–water (1:1). This one pot domino Knoevenagel condensation/Micheal addition reaction provides excellent yield of bis-coumarinyl methane derivatives with lots of advantages like shorter reaction time, eco-friendly reaction medium, simple work up, recyclability of the catalyst and chromatography-free purification. Moreover, the synthesized compound was exploited to develop bis-coumarinyl methylene-based nanostructured materials of special interests which were investigated by UV–Vis, fluorescence spectroscopy, imaging in scanning electron microscope and atomic force microscope. Our UV–Vis and fluorescence study indicated that some of the organic compounds are organized as H-aggregate in the thin film. We also investigated I–V characteristics of the thin film of some of the selective compounds which showed write-once-read-more memory switching behaviour onto the thin film under investigations. [ABSTRACT FROM AUTHOR]

Seven arylbis(indolyl)methanes were synthesized by electrophilic substitution reaction of aromatic aldehydes on indole using glacial acetic acid as catalyst in aqueous media under ultrasonic irradiation. The synthesized bis-indole derivatives were characterized using elemental analysis, 1H and 13C NMR, FT-IR spectroscopy, and mass spectrometry and were screened for their nematicidal activity against the root knot nematode Meloidogyne incognita. The efficiency of the synthesized compounds was evaluated in vitro by egg hatching and mortality tests. All tested compounds showed significant nematicidal potential, and the nitro substituted derivative, 3,3′-[(4-nitrophenyl)methylene]di(1H-indole), exhibited the highest activity. [ABSTRACT FROM AUTHOR]

In this research, highly efficient protocols for the production of pyrido[2,3-d:6,5-d′]dipyrimidine and bis(pyrazolyl)methane derivatives using an acid ionic liquid namely [Et3N-SO3H][MeSO3] have been reported (bis(pyrazolyl)methanes have been produced via two methods, the pseudo three-component and the pseudo five-component reactions). [Et3N-SO3H][MeSO3] was superior than many of the reported catalysts in terms of two or more of these factors: turnover frequency (TOF), turnover number (TON), the reaction temperature, yield, the reaction time, simplicity in workup, and the reaction conditions. [ABSTRACT FROM AUTHOR]

Pyrazole and its derivatives are an important class of heterocyclic compounds, present in several biologically and medicinally active compounds. Compounds containing 2,4-dihydro-3H-pyrazol-3-one structural motif, including 4,4′-(arylmethylene)-bis-(1H-pyrazol-5-ols), have attracted interest because they exhibit a wide range of biological activities and as the chelating and extracting reagents for different metal ions. There are two main strategies to the synthesis of bis(pyrazolyl)methane derivatives. The first involves the one-pot pseudo three-component reactions of 3-methyl-5-pyrazolone derivatives and aldehydes, and the second approach is the one-pot pseudo five-component reactions of β-keto esters, hydrazins and aldehydes. This review includes the recent investigation in the multi-component synthesis and their applications of bis(pyrazolyl)methanes and describes the literature reports for the period of 2014 to early 2021. [ABSTRACT FROM AUTHOR]

A sulfonated polyethylene glycol-supported nano-magnetite (Fe3O4@PEG-SO3H) has been prepared, characterized, and evaluated as a magnetically recoverable core–shell nanocomposite catalyst for the synthesis of bis(indolyl)methane derivatives through the one-pot reaction of indole and aldehydes. Green and eco-friendly reaction profile, mild reaction conditions (room temperature), simple procedure, short reaction times, and excellent yields make this method versatile and demonstrate its practical merit for the synthesis of the title compounds with potential pharmacological activity. Furthermore, the excellent catalytic performance, thermal stability, and easy separation and reusability of the prepared nanocatalyst without significant deterioration in its catalytic activity make it a good heterogeneous system and a superior alternative to the existing protocols. [ABSTRACT FROM AUTHOR]

The immobilization of AlCl3, an extremely hygroscopic Lewis acid, on graphene oxide as a support material with a high surface area was studied. The obtained solid material was characterized by FTIR spectroscopy, TGA/DTA analysis, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy and used as an efficient and bench-top environmentally benign catalyst for the preparation of bis (pyrazolyl)methane derivatives through the condensation of aldehydes and 3-methyl-l-phenylpyrazol-5-one. The catalyst is reusable for at least nine times with a negligible loss in its catalytic activity. [ABSTRACT FROM AUTHOR]

With the aim of establishing a structure-analgesic activity relationship, a series of picolylamides of 2-hydroxy-4-oxo-4H-pyrido[1,2-a]-pyrimidine-3-carboxylic acids were synthesized. The characteristics of the spatial structure of this group of substances were assessed. The results of pharmacological studies identified compounds in the study series with marked analgesic properties. However, it was noted that the transition from 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxamides to the structurally similar pyrido[1,2-a]pyrimidine derivatives was generally accompanied by some decrease in analgesic activity. [ABSTRACT FROM AUTHOR]

The studies concerning coordination compounds of various salts of iron(II) with tris(pyrazol-1-yl)methane derivatives (HC(pz)3) are discussed. The results of a number of studies on the synthesis and investigation of the homo- and heteroligand iron(II) complexes with tris(3,5- dimethylpyrazol-1-yl)methane (HC(3,5-Me2pz)3) are considered. The study of the temperature dependence μeff (T) showed that the spin crossover (SCO) 1A1↔5T2 observed in a series of the compounds discussed is accompanied by thermochromism (color change pink (purple) ↔ colorless). Specific features of the SCO and their dependence on the outer-sphere anion in the iron(II) complexes are discussed. The data of the recently published work devoted to the synthesis of the iron(II) complexes with three N-substituted HC(pz)3 derivatives (general formula xL, where x = H, CH2C6H5 (Bn) and p-SO3C6H4CH3 (Ts)) are considered. [ABSTRACT FROM AUTHOR]

The structure of two lanthanide (Ln = Nd, Ho) complexes with dipivaloylmethane (Hdpm) is studied at 150(2) K by single crystal X-ray diffraction. The crystallographic data are as follows for [Nd(dpm)3]2: space group P21/n, a = 12.3281(3) Å, b = 27.8118(6) Å, с = 21.9035(5) Å, β = 105.241(1)°, V = 7245.8(3) Å3, Z = 4, R = 0.0333; for [Ho(dpm)3]2: space group P21/n, a = 12.2067(6) Å, b = 27.5626(13) Å, с = 21.8624(10) Å, β = 105.188(1)°, V = 7098.6(6) Å3, Z = 4, R = 0.0321. Both structures are molecular and consist of neutral [Ln(dpm)3]2 dimeric molecules. The thermogravimetric studies demonstrate that Ln(dpm)3 volatility increases in the series from [La(dpm)3]2 to Yb(dpm)3. [ABSTRACT FROM AUTHOR]

To extend the use of phase change materials (PCMs) of those with good performance, tris(hydroxymethyl)aminomethane (THAM) is embedded in silica gels (SG) (pore diameter, d = 15-100 nm) and in controlled porous glasses (CPG) (nominal d = 12-100 nm). The THAM/SG and THAM/CPG composites are characterized by SEM and XRD. Latent heat storage performance of THAM/SG and THAM/CPG is investigated using differential scanning calorimetry, showing size dependence of phase transition temperature, enthalpy change and supercooling. THAM in the nanopores displays stable transition temperature and heat storage capacity in a short-term thermal cycling. The bulk and the nanosized THAM own the same diffraction patterns. The encapsulation of phase change material in nanoporous media is a promising way of tuning the thermal energy properties of those ideal PCMs for use in a wider range of temperature. [ABSTRACT FROM AUTHOR]

An effective method was developed for the preparation and x-ray diffraction analysis of the spatial structure of 7-hydroxy-5-oxo-2,3-dihydro-5 H-[1, 3]thiazolo[3,2- a]pyrimidine-6-carboxylic acid ethyl ester, which is of interest as a starting material for the synthesis of new, potentially biologically active derivatives of thiazolo[3,2- a]pyrimidine hydrogenated in the thiazole part of the molecule. [ABSTRACT FROM AUTHOR]

Trimethyl(tosylethynyl)silane reacted in ethyl ether at 20°С with diphenyldiazomethane affording 3 Н-pyrazole, a product of 1,3-dipolar cycloaddition against Auwers rule. The reaction with 9-diazofluorene is less selective, but its regioselectivity is also governed by the steric effect of the bulky trimethylsilyl substituent at the triple bond С≡С. The adduct with diphenyldiazomethane at boiling in methanol or keeping in glacial acetic acid in the presence of a catalytic quantity of conc. HSO undergoes the Van Alphen-Hüttel rearrangement by the migration of the phenyl substituent to the atom N in the 1 Н-pyrazole. The same 1 Н-pyrazole together with a product of nitrogen elimination, trimethylsilyl substituted cyclopropane, is formed in the 2: 1 ratio at boiling in benzene. A similar behavior is observed in the glacial acetic acid for the anti-Auwers adduct of 9-diazofluorene. It suffers nitrogen elimination at boiling in benzene converting in spirocyclic cyclopropene. The Auwers adduct of 9-diazofluorene at boiling in methanol transforms due to the van Alphen-Hüttel rearrangement into the corresponding 4 Н-pyrazole that undergoes a hydrodesilylation to give a derivative of 1 Н-pyrazole, 3-tosyl-1(2) H-dibenzo[e,g]indazole. [ABSTRACT FROM AUTHOR]

A brief overview of methane dehydroaromatisation over MoO/H-ZSM-5 derived catalysts, the deposition of carbonaceous residues from methanol over H-mordenite and the role of binders in zeolite catalysed reactions is presented. The selective poisoning of methane cracking catalysts is proposed as a potential strategy for the development of methane dehydroaromatisation catalysts. In the case of methanol conversion over H-mordenite, evidence is presented for the formation of larger alkylated aromatics, such as methylnaphthalenes. Binders, ubiquitous components of technical catalysts, have been documented to have a number of important effects often outweighing laboratory based modifications, and therefore, consideration of their effects should be made at an early stage of catalyst development. [ABSTRACT FROM AUTHOR]

Methylation of formaldehyde with various aromatics under functional ionic liquids catalysis has been developed. Among the ionic liquids investigated, triphenyl-(4-sulfobutyl)-phosphonium triflate ([TTPBs][CFSO]) showed high activity and afforded excellent yields of diarylmethane derivatives. A mechanism for the catalytic performance of [TTPBs][CFSO] is proposed. Besides, the catalyst can simply be separated from the reaction mixture by centrifugation and be recycled ten times without noticeable loss of activity. Graphical Abstract: Diarylmethane derivatives were successfully synthesized from the methylation of formaldehyde with aromatics using efficient and recyclable functional ionic liquids as catalysts, excellent yields and selectivities were obtained under solvent free conditions. The catalyst was reused at least ten consecutive recycles without noticeable loss in its catalytic activity. Meanwhile, the usability of catalyst was explored. [ABSTRACT FROM AUTHOR]

A PIV study of a conical premixed methane-air Bunsen flame has shown that the inside of the cone has a complex gas-dynamic structure. In this system, the velocity of the gas flow entering the flame front varies in different parts of the flame cone and the stream tubes are not straight. The Landau-Markstein effect is discussed in the interpretation of the experimental data. A method of processing PIV measurement results is proposed that improves the accuracy of determining the burning velocity and allows a quantitative determination of the catalytic effect of submicron TiO particles, which is proportional to the particle surface area. The relative increase in the burning velocity is 2% per each ≈0.01 cm/cm (particle surface/gas volume) of the total specific surface area of the particles. The experimental data are well described by modeling using well-known literature data on the detailed mechanism of chemical reactions and the mechanism of catalytic oxidation of methane with oxygen on metal oxides. [ABSTRACT FROM AUTHOR]

New Schiff bases of 5-aminouracil have been synthesized by the 1: 1 condensation with N-heterocyclic aldehydes. The new compounds were characterized by elemental analyses and H NMR spectroscopy. Under similar conditions, the condensation of 6-aminouracil with aldehydes failed to yield the desired Schiff base. Interestingly, the reaction of 6-aminouracil with 6-methylpyridine-2-carbaldehyde resulted in an unusual compound, 2-methyl-6-[7-(6-methylpyridin-2-yl)-2,4-dioxo-1,2,3,4-tetrahydropyrimido[4,5- d]pyrimidin-5-yl]-pyridinium methanesulfonate, whose crystal structure was elucidated by X-ray crystallography. [ABSTRACT FROM AUTHOR]

N-Sulfinyl-3-(trifluoromethyl)aniline reacted with bicyclo[2.2.1]hept-2-ene and bicyclo[2.2.1]-hepta-2,5-diene to give the corresponding Diels-Alder adducts which were oxidized to 8-trifluoromethyl-2,3,4,4a,6,10b-hexahydro-5 λ-1,4-methanodibenzo[ c, e][1,2]thiazine-5,5(1 H)-diones. The cycloaddition occurred predominantly with participation of the S=N-C=C fragment of N-sulfinyl-3-(trifluoromethyl)aniline and exclusively at the endo side of bicyclo[2.2.1]heptenes. [ABSTRACT FROM AUTHOR]

Synthesis procedures for new coordination compounds of iron(II) with tris(pyrazol-1-yl)methane (HC(pz)), containing cluster anions in the outer sphere, of the composition [Fe{HC(pz)}][MoCl]•2HO ( I), [Fe{HC(pz)}][MoBr]•HO ( II), and [Fe{HC(pz)}][ReS(CN)]•2HO ( III) are developed. The compounds are studied by static magnetic susceptibility, electronic, IR, and Mössbauer spectroscopic methods. The magnetochemical study shows that in the polycrystalline phases of all compounds the spincrossover А ⇔ Т is observed which is accompanied by thermochromism. [ABSTRACT FROM AUTHOR]

Docking of a series of methanepyrido[1,2- a][1,5]diazocin[(-)-cytisine derivatives to the active center of the nicotinic acetylcholine receptor was used to generate a set of potential substances for the treatment of cognitive dysfunction. The results from these studies led to the conclusion that six of the 21 structures were potential inhibitors of the nicotinic acetylcholine receptor. Experimental testing confirmed that the study compounds had nootropic actions and allowed the most active of these to be selected for further investigation. [ABSTRACT FROM AUTHOR]

We report an efficient green process for synthesis of bis(indolyl)methane derivatives under solvent-free conditions by use of a new solid acid catalyst, BiCl-loaded montmorillonite K10. The catalyst was characterized by SEM, BET surface area measurement, and determination of its surface acidity by temperature-programmed desorption measurements. The salient features of the procedure are its simplicity, ease of preparation of the catalyst, cost effectiveness, excellent yield with short reaction time, reusability of the catalyst, and enhancement of the acidity of montmorillonite K10 catalyst by BiCl loading. Graphical Abstract: Pictogram [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

Data on aqueous systems mainly based on antipyrine and diantipyrylmethane derivatives, which undergo segregation as a result of protolytic interactions with acids (haloacetic, benzoic, and naphthalene-2-sulfonic acids and pyrocatechol), are presented. The results of the physicochemical analysis of the corresponding ternary and quaternary systems are given. The distribution of metal ions between liquid phases was studied, and procedures for the combined determination of many metal ions in alloys and environmental materials are proposed. The advantage of the above extraction systems is the exclusion of the use of an organic solvent. [ABSTRACT FROM AUTHOR]

An eco-friendly and expedient procedure for one-pot synthesis of bis-(indolyl)methane derivatives via electrophilic substitution reaction at C-3 position of indole with various aldehydes has been developed by using silica-diphenic acid as a novel heterogeneous catalyst. This method has various promising features such as short reaction time, easy work-up procedure, good yield of products and remarkable activity and selectivity of the catalyst. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

We propose several simple and effective methods for the synthesis of previously unknown trinitromethyl borohydrides and their complexes with simple cyclic ethers and aromatic nitrogen- containing heterocycles, whereas acyclic ethers did not form such complexes. The data from physicochemical investigations showed that these unique compounds contain directly linked oxidizing and reducing fragments. Some transformations of trinitromethylborane complexes were demonstrated, which can occur by cleavage of all types of bonds formed by boron atom in the starting compounds. [ABSTRACT FROM AUTHOR]

Synthesis of chiral functionalized menthane derivatives was carried out by Diels-Alder reaction from levoglucosenone and (2 E,4 E)-6-methylhepta-2,4-dienyl acetate.In extension of research [1] on development of preparation methods for polyfunctional menthane derivatives we explored the possibility of an isopropyl group direct introduction in the course of Diels-Alder reaction. [ABSTRACT FROM AUTHOR]

We have previously demonstrated that the non-digestible fraction (NDF) from common cooked beans ( P. vulgaris L., cv Negro 8025) inhibits azoxymethane (AOM)-induced colon cancer and influences the expression of genes involved in the induction of apoptosis and cell cycle arrest through the action of butyrate. The objective of this study was to identify cell cycle alterations and morphological changes induced by treatment with AOM and to examine the formation of colonic aberrant crypt foci (ACF) in male Sprague Dawley rats fed with these beans. Rats were fed control diets upon arrival and were randomly placed into four groups after one week of acclimatization: control, NDF (intragastric administration), NDF + AOM and AOM. Rats treated with NDF + AOM exhibited a significantly lower number of total colonic ACF with a notable increase in the number of cells present in the G phase (83.14 %); a decreased proliferation index was observed in the NDF + AOM group when compared to AOM group. NDF + AOM also displayed a higher number of apoptotic cells compared to AOM group. NDF of cooked common beans inhibited colon carcinogenesis at an early stage by inducing cell cycle arrest of colon cells and morphological changes linked to apoptosis, thus confirming previous results obtained with gene expression studies. [ABSTRACT FROM AUTHOR]

The demand for dyes with solvatochromic properties has increased in the last few years, mainly due to their wide range of applications in the analytical and industrial fields, such as in the textile industry. The phenomenon of solvatochromism is associated with the differential solvation of the ground and excited states of the solvatochromic compounds, leading to an important tool for the study of the nature of solute–solvent interactions. In this paper we report the synthesis of new bis(indolyl)methane derivatives bearing arylthiophene spacers (2a–d) functionalized with electron-donating and electron-withdrawing groups, and the photophysical studies in different solvents, such as ethanol, acetonitrile, dichloromethane, trichloromethane, dimethylsulfoxide, diethylether and 1,4-dioxane. Aiming to explore their solvatochromic behaviour in the ground and excited states, all solvents employed have different hydrogen-bond donor abilities. The largest colour modifications were visualized for compound 2b, the solution colours of which are orange in DMSO, blue in trichloromethane, green in dichloromethane and purple in 1,4-dioxane. A negative solvatochromism was observed in 2b and a positive one in 2a, 2c and 2d. [ABSTRACT FROM AUTHOR]

We recently reported that novel ring-substituted analogs of 3,3′-diindolylmethane (ring-DIMs) have anti-androgenic and growth inhibitory effects in androgen-dependent prostate cancer cells. The objectives of this study were to confirm the ability of 4,4′- and 7,7′-dibromo- and dichloro-substituted ring-DIMs to inhibit androgen-stimulated proliferation of androgen-dependent LNCaP human prostate cancer cells using a non-invasive, real-time monitoring technique. In addition, their ability to induce apoptotic and necrotic cell death in androgen-dependent as well as -independent (PC-3) prostate cancer cells was studied. Prostate cancer cells were treated with increasing concentrations of DIM and ring-DIMs (0.3-30 μM) and effects on cell proliferation were measured in real-time using an xCELLigence cellular analysis system. Chromatin condensation and loss of membrane integrity were determined by Hoechst and propidium iodide staining, respectively. Apoptotic protein markers were measured by immunoblotting and activation of caspases determined using selective fluorogenic substrates. Intra- and extracellular concentrations of DIM and ring-DIMs were assessed by electrospray ionization tandem mass spectrometry. Ring-DIMs inhibited androgen-stimulated LNCaP cell proliferation and induced apoptosis and necrosis in LNCaP and PC-3 cells with 2-4 fold greater potencies than DIM. DIM and the ring-DIMs increased caspases −3, −8 and −9 activity, elevated expression of Fas, FasL, DR4 and DR5 protein, and induced PARP cleavage in both cell lines. The cytotoxicity of the most potent ring-DIM, 4,4′-dibromoDIM, but not the other compounds was decreased by an inhibitor of caspase −3. The 4,4′-dibromoDIM was primarily found in the extracellular medium, whereas all other compounds were present to a much larger extent in the cell. In conclusion, ring-DIMs inhibited prostate cancer cell growth and induced cell death in LNCaP and PC-3 cells with greater potencies than DIM; they also structure-dependently activated different cell death pathways suggesting that these compounds have clinical potential as chemopreventive and chemotherapeutic agents in prostate cancer, regardless of hormone-dependency. [ABSTRACT FROM AUTHOR]

A novel ligand with double sulfinyl groups, bis(benzylsulfinyl)methane, was synthesized by a new method and its two lanthanide (III) complexes were synthesized and characterized by element analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, HNMR and UV spectra. The results indicated that the composition of these complexes was REL(ClO)·3HO (RE = Tb (III), Dy (III), L = CHCHSOCHSOCHCH). The FT-IR results revealed that the perchlorate group was bonded with the lanthanide ion by the oxygen atoms, and the coordination was bidentate. The fluorescent spectra illustrated that both the Tb (III) and Dy (III) complexes displayed characteristic fluorescence in solid state, especially for the Tb (III) complex, the peak of D → F of the Tb (III) ion in 544 nm was stronger than that of others. It indicated that the Tb (III) complex could emit purer green fluorescence. By analysis fluorescence and phosphorescence spectra, it was found that the ligand had the advantage to absorb energy and transfer it to the Tb (III) and Dy (III) ions. The phosphorescence spectra and fluorescence lifetimes of the complexes were also measured. [ABSTRACT FROM AUTHOR]

The reactions of 2,4-dihydroxybenzoic and 4-aminobenzoic acids with diphenyldiazomethane are accelerated in the presence of 2,4,6-trinitrotoluene as π-acceptor. The catalytic effect of the latter is determined by the formation of charge-transfer complexes with the acids, which facilitates proton abstraction and stabilizes the corresponding anions. [ABSTRACT FROM AUTHOR]

An improved method for the preparation and purification of ethyl 2-hydroxy-4-oxo-4H-pyrido[1,2-a]-pyrimidine-3-carboxylates is proposed. According to 1H and 13C NMR spectroscopic data the synthesized compounds exist in DMSO solution in the 2-hydroxy-4-oxo form while in the crystal (at least for the case of the unsubstituted derivative) X-ray analysis shows that it occurs in the bipolar 2,4-dioxo form. [ABSTRACT FROM AUTHOR]

We studied the hydrolysis of gas-phase carbon tetrachloride (CCl4), chloroform (CHCl3), and dichloromethane (CH2Cl2) over a metallic Fe surface for its application in combination with air stripping and soil vapour extraction. The effects of chlorocarbon concentration, type and preparation of the iron-containing material, humidity, and temperature on process performance are reported. The hydrolysis of chlorinated methane derivatives is catalysed by metallic iron resulting in a noticeable decrease of the reaction temperature. The reaction kinetics were found to be consistent with the Langmuir-Hinshelwood model. [ABSTRACT FROM AUTHOR]

Spectroscopic parameters of trinitromethane derivatives RC(NO2)3 (R = F, Cl, Br, I, NC, NF2, N3) were determined. Vibrational frequencies and modes were calculated and the assignment of experimental spectra was performed. Spectral features due to the mutual influence of the C(NO2)3 group and other atomic groups and particular atoms were revealed. [ABSTRACT FROM AUTHOR]

The molecular structures of trinitromethane derivatives XC(NO2)3 (X = F, Cl, Br, NC, NF2, N3) were studied using the density functional approach. The rules for changing the configurations of substituents in these compounds were revealed. Acceptability of the method employed for the calculations of trinitromethane derivatives is discussed. [ABSTRACT FROM AUTHOR]

An original method was developed for the synthesis of functional derivatives of triallylmethane (CH=CH-CH)C-X (X = OH, NH, or SCOPh) based on reactions of triallylborane with the corresponding derivatives of carbonic acid (ethylene carbonate, diethylcyanamide, and 0,S-dimethyidithio carbonate) at 110-120 °C. [ABSTRACT FROM AUTHOR]

A series of tetrapodal derivatives of tetraphenylmethane were synthesized and characterized. Crystals obtained from tetrakis(4-acetamidophenyl)methane ( 1c) and from tetrakis[4-(4-aminobenzamido)phenyl]methane ( 2b) were analyzed by X-ray diffraction. The analyses pointed to the crystal packing problems faced by molecules of this kind by showing that the crystals, with composition 1c·2DMF·2H2O and 2b·2DMSO, respectively, contained cocrystallized solvent molecules. The solvent molecules were found in both cases to be held in place by H bonds; in the case of 2b·2DMSO they occupied channels running along the b axis. Tetrakis(4-aminophenyl)methane ( 1b) was used in polycondensation reactions with terephthalic acid, under modified Yamazaki conditions, to produce rigid aromatic polyamide networks. The networks were obtained as gels encompassing the whole volume of the reaction mixture. The volume of the gels did not vary noticeably upon changing the solvent (1-methyl-2-pyrrolidone) with less polar solvents, but the gels collapsed upon drying. No crystallinity was observed. [ABSTRACT FROM AUTHOR]