Benzene Solution Research Articles

Regioselective rearrangement reactions of naphthyl naphthylmethyl ethers by using Lewis acids or UV light irradiation

Reaction of 1-naphthyl naphthylmethyl ethers 1 and 2 with Lewis acids (BF3-Et2O or Et2AlCl) in CH2Cl2 produced rearranged products of the naphthylmethyl group to the 2- and 7-positions of the naphthalene, whereas rearrangement of 2-naphthyl ethers 3 and 4 proceeded to the 1-position. When benzene solution of compound 1 was irradiated, rearrangement to the 4-position proceeded, whereas rearrangement of 2 proceeded to the 2- and 4-positions. Photoinduced rearrangement of 3 and 4 proceeded to the 1-position as in the reaction using Lewis acids. In the reaction with Lewis acids, ion pair consists of Lewis acid-coordinated naphthoxy anions and naphthylmethyl cations, and in the photoreaction, radical pair generated by homolytic cleavage of the C-O bond, are proposed to be intermediates. Calculations of the negative charge distribution and the spin density of the intermediates showed that the regioselectivity of the reactions can be explained by the charge density and spin density of each fragment, steric hindrance, and solvent cage effect.

Safety and quality of sweet and cream oil of various domestic manufacturers and determining its falsification

The entry of domestic products into European markets has set Ukrainian entrepreneurs the task - to increase their production, ensure safety, quality and competitiveness. The purpose of the study is to assess the safety and quality of sweet butter obtained from various domestic producers, and to determine its falsification by the generally accepted method and the developed patented express method. The object of the study was the assessment of organoleptic, physicochemical, microbiological parameters and falsification of sweet butter obtained from various milk processing enterprises of Ukraine: Lustdorf LLC and Fooddevelopment LLC, Vinnytsia region; TDV "Yagotinsky butter factory"; PE "SIMOL", Kyiv region; State Enterprise "Starokostiantyniv Dairy Plant", Khmelnytsky region. Analytical, organoleptic (appearance, color, consistency, smell, taste) were used to achieve the research goal; physicochemical (mass fraction of moisture, mass fraction of fat, titrated acidity of plasma oil and acidity of fatty phase of oil, mass fraction of sodium chloride, determination of margarine and vegetable fats), microbiological (KMAFАNM, the presence of Escherichia coli bacteria, pathogenic microorganisms, in particular genus Salmonella, species Listeria monocytogenes; molds) and variation-statistical research methods. Developed patented express method for detecting adulteration of sweet cream oil using resorcinol solution in benzene with a mass fraction of 5.0% and concentrated hydrochloric acid can be used in production laboratories at milk and dairy products, supermarkets, wholesale bases, shops and public laboratories. in laboratories of veterinary and sanitary examination in agro-industrial markets. The oil produced by different manufacturers according to organoleptic parameters: appearance, color, texture, smell and taste met the requirements of DSTU 4399: 2005. According to physical and chemical parameters, the samples of sweet butter also met DSTU 4399: 2005, except for sample № 5 (SE "Starokostiantyniv Dairy Plant" of Khmelnytsky region), which showed an increase of + 0.6% by weight of sodium chloride. Research has established the falsification of sweet cream oil according to the developed patented method, according to which the probability in the indicators was 99.9%, produced: TDV "Yagotinsky butter factory" - up to 1.5% (light purple color) oil and "Farm Peasant", manufacturer LLC Food Development "- from 1.6 to 5.0% (bright purple color). Microbiological parameters of sweet butter: KMAFANM, bacteria of the Escherichia coli group, bacteria of the genus Salmonella, species Listeria monocytogenes, as well as molds met the requirements of DSTU 4399: 2005. Key words: sweet and butter, dairy processing enterprises of Ukraine, organoleptic, physicochemical, microbiological indicators, falsification, safety, quality.

Photophysics of α-azinyl-substituted 4,4-difluoro-8-(4-R-phenyl)-4-bora-3a,4a-diaza-s-indacenes

A series of 15 compounds of the general formula 8-(4-R1-phenyl)-3-R2-5-R3-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene, where R1 = NMe2, Me, Br, CN, or NO2, and R2, R3 = H, acridin-9-yl, or 6-phenyl-[1,2,5]oxadiazolo[3,4-b]pyrazyne-5-yl, have been synthesized and investigated for their fluorescence properties in tetrachloroethylene and benzene solutions. For tetrachloroethylene solutions of 8-(4-dimethylaminophenyl)-substituted compounds, bright fluorescence from a locally excited state has been observed. The same compounds in benzene show intramolecular charge transfer with an increased Stokes shift and greatly reduced radiative rate and fluorescence quantum yield. The rest of the compounds are characterized only by locally-excited fluorescence both in tetrachloroethylene and benzene. Their nonradiative rate constant knr obeys the equation ln knr = a + bnacr + cσp, where σp is the Hammett constant of the para-substituent, nacr is the number of acridine substituents; a, b, c are fitting parameters. The linearity of the formula implies an additive effect of the substituents on the activation energy of the nonradiative decay.

SYNTHESIS OF AMINOMETHOXY DERIVATIVES OF CYCLOHEXANOL AND STUDYING THEM AS BACTERICIDE INHIBITORS

Based on cyclohexanol, cyclic amines (piperidine, morpholine, hexamethyleneimine), and formaldehyde, new Mannich bases have been synthesized. The reaction was carried out at a temperature of 78–800C for 4–5 h in a benzene solution at an equimolar ratio of the starting components. The yield of compounds was 69–75%. The physicochemical data of the synthesized compounds were determined. The composition and structure of the target products were confirmed by elemental analysis, IR, 1H and 13C NMR spectroscopy, and mass spectrometry. Their effect on the vital activity of sulfate-reducing bacteria of the "Desulfovibrio desulfuricans" type at three concentrations (25; 50; 100 mg/l) was studied. The obtained compounds showed high bactericidal properties, 1% solutions of these compounds in isopropyl alcohol at a concentration of 100 mg/l showed 100% bactericidal effect. A 1% solution of the compound with a fragment of morpholine already at a concentration of 50 mg/l exhibits a 100% bactericidal effect. Compounds with a fragment of piperidine and hexamethyleneimine at a concentration of 50 mg/l showed 96.2 and 98% bactericidal effects, respectively. And at a concentration of 25 mg/l, the bactericidal effect of all three compounds was 16.4%, 36.4%, and 58.2%, respectively. The results obtained show that the synthesized compounds showed more bactericidal properties compared to the industrially used bactericide-inhibitors АМДОР ИК-7 and АМДОР ИК-10 taken as a standard. Established, that these aminomethoxy derivatives of cyclohexanol affect bacteria at very low concentrations, they can be proposed as effective inhibitors against sulfate-reducing bacteria

AMINOMETHOXY DERIVATIVES OF CYCLOHEXANOL AS BIOCORROSION INHIBITORS

Based on cyclohexanol, aliphatic amines (diethylamine, dipropylamine, dibutylamine, dihexylamine), and formaldehyde, new Mannich bases have been synthesized. The reaction was carried out at a temperature of 78–80°C for 4–5 h in a benzene solution at an equimolar ratio of the starting components. The yield of compounds was 63–80%. The physicochemical data of the synthesized compounds were determined. The composition and structure of the target products were confirmed by elemental analysis, IR, 1H and 13C NMR spectroscopy. Their influence on the vital activity of sulfate-reducing bacteria (SRB) of the "Desulfovibrio desulfuricans" type at three concentrations (25; 50; 100 mg/l) was studied. The resulting compounds showed high bactericidal properties. 1% solutions of these compounds in isopropyl alcohol at a concentration of 100 mg/l showed a 100% bactericidal effect. Given that these aminomethoxy derivatives of cyclohexanol affect bacteria at very low concentrations, they can be proposed as effective inhibitors against sulfate reducing bacteria. Keywords: cyclohexanol, aliphatic amines, Mannich bases, sulfatereducing bacteria, inhibitor-bactericides, biocorrosion.

La, S, N tri-doped TiO2/nickel foam as efficient photoelectrode for degradation of BTX solution under visible light irradiation

La, S, N tri-doped TiO2 nanoparticles were prepared by facile sol–gel method. Investigation of the optical and photochemical properties of the prepared samples reveals the simultaneous introduction of the metal and non-metal dopants into TiO2 substantially decreases the recombination rate of charge carriers, as well as increases visible light sensitization of TiO2. The prepared nanoparticles were immobilized onto nickel foam as an efficient substrate. The photoelectrocatalytic reactions were conducted to degrade the benzene, toluene and p-xylene (BTX) aqueous solution under visible light irradiation. After 180 min illumination and 0.8 V applied potential, the highest degradation rate of BTX solution are 83.7%, 71.4% and 62.28% for benzene, toluene and p-xylene, respectively. Under the same experimental condition, the COD analysis shows the mineralization of BTX solution is 51.3 %. The good photoelectrocatalytic performance of the prepared photoanode is attributed to the improved separation of charges caused by the introduction of La, S and N dopants. The recyclability of the prepared photoanode was studied under 6 reaction cycles which revealed the high stability of the photoanode for degradation of BTX solution.

Nanoporous-crystalline and amorphous films of PPO including off-on vapochromic fluorescent 7-hydroxy coumarin guests

This study examines the preparation of nanoporous-crystalline and amorphous films of poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) containing 7-hydroxy coumarin (i.e., umbelliferone) for the detection of chloroform vapours. Chloroform is selected as the volatile contaminant model being considered harmful and possibly carcinogenic after prolonged exposure. Umbelliferone is chosen as a fluorescent molecule being mostly unemissive in the solid-state and apolar media. α and β nanoporous-crystalline and amorphous PPO films presenting ≈40 μm thickness have been prepared by casting from carbon tetrachloride, benzene and chloroform solutions, respectively, whereas umbelliferone inclusions (1–2 wt%) have been realized in saturated methanol mixtures. Films show fluorescence maximum at about 430 nm with very low quantum yield (Φ F ) of around 1–2%, and particularly reduced in the α and β PPO films, thus suggesting stronger molecular interactions which might facilitate fluorescence self-quenching. It has demonstrated that the exposure to chloroform vapours under saturated conditions (10 5 ppm) turns rapidly on the fluorescence of the polymer films thanks to the solvation effect of the solvent and in agreement with the Φ F of 7% of umbelliferone in chloroform. Notably, a slower response was detected by using dichlorometane as VOC, possibly due to the weaker H-donor strength with respect to chloroform. It was worth noting, that the phenomenon results fastest for the α PPO films, i.e., in case of the lowest Φ F and quenched emission. Vapochromism appears therefore sensitive to the different fluorophore confinement, and the reported results may open new avenues for the rapid detection of VOC vapours. • Nanoporous-crystalline PPO films were prepared and characterized by WAXD and FTIR. • Umbelliferone inclusions in PPO films showed very low Φ F of around 1–2%. • Exposure to CHCl 3 vapours turned the fluorescence on. • Faster vapochromism for the α and β co-crystalline PPO films.

Adsorption behaviour and mechanism of benzene, toluene and m-xylene (BTX) solution onto kaolinite: Experimental and molecular dynamics simulation studies

Benzene, toluene and m-xylene (BTX) pollution due to industrial development has been a serious problem in recent years. The environmental mobility and fate of BTX in soils are mainly controlled by interactions with soil minerals such as kaolinite. Therefore, it is crucial to characterise the molecular-scale interactions that occur between BTX and kaolinite. In this study, molecular dynamics (MD) simulations, isothermal titration calorimetry (ITC) and batch adsorption experiments were performed to investigate the molecular interactions between BTX and kaolinite. Results revealed that the adsorption capacity of the kaolinite 00 1¯ surface was stronger than that of the kaolinite 001 surface due to the weaker hydrophilicity. BTX molecules were adsorbed on kaolinite surfaces by forming weak hydrogen bonds with the oxygen basal surface. The adsorption energy and adsorption isotherm obtained by the MD simulations were similar to those from the ITC and batch experiments, which validated the reliability of the MD simulations. The adsorption of BTX onto kaolinite was well described by the pseudo first-order kinetic and Langmuir-Freundlich isotherm model. Overall, performing MD simulations combined with experiments revealed the BTX adsorption mechanisms from a molecular interaction perspective.

Chemoprotection by Kolaviron of Garcinia kola in Benzene-induced leukemogenesis in Wistar rats

ABSTRACT Kolaviron (KV) is a biflavonoid phytoconstituent of defatted Garcinia kola seeds that possessed antiproliferative and pharmacological activities. Benzene is an industrial solvent that, however, constitutes occupation hazard, leading to hematological disturbance and leukemia. Therefore, the potency of kolaviron against benzene-induced hematological and myeloid toxicity leading to leukemia was investigated in a rat model. Preleukemic conditions were induced in Wistar rats by intravenous administration of benzene solution. Following induction, 200 mg/kg kolaviron was administered orally for seven days. Hematological parameters, percentage blast cell occurrence and blood cell morphology were compared between baseline control and leukemic rats with or without kolaviron treatment. Plasma activity of arylesterase of paraoxonase-1, total thiol and advanced oxidation protein products (AOPPs) along with clastogenicity and bone marrow architecture was assessed. Kolaviron restored altered hematology, reduced the occurrence of blasts and improved blood cell morphology. Kolaviron also decreased levels of AOPPs, increased total thiol, improved arylesterase activity and mitigated clastogenicity and dysplasia induced in leukemic rats. In conclusion, kolaviron protected against benzene-induced hematological and myeloid toxicities that are implicated in leukemia.

Access to a Labile Monomeric Magnesium Radical by Ball‐Milling

AbstractIn order to isolate a monometallic Mg radical, the precursor (Am)MgI⋅(CAAC) (1) was prepared (Am=tBuC(N‐DIPP)2, DIPP=2,6‐diisopropylphenyl, CAAC=cyclic (alkyl)(amino)carbene). Reduction of a solution of 1 in toluene with the reducing agent K/KI led to formation of a deep purple complex that rapidly decomposed. Ball‐milling of 1 with K/KI gave the low‐valent MgI complex (Am)Mg⋅(CAAC) (2) which after rapid extraction with pentane and crystallization was isolated in 15 % yield. Although a benzene solution of 2 decomposes rapidly to give Mg(Am)2 (3) and unidentified products, the radical is stable in the solid state. Its crystal structure shows planar trigonal coordination at Mg. The extremely short Mg−C distance of 2.056(2) Å indicates strong Mg−CAAC bonding. Calculations and EPR measurements show that most of the spin density is in a π* orbital located at the C−N bond in CAAC, leading to significant C−N bond elongation. This is supported by calculated NPA charges in 2: Mg +1.73, CAAC −0.82. Similar metal‐to‐CAAC charge transfer was calculated for M0(CAAC)2 and [MI(CAAC)2+] (M=Be, Mg, Ca) complexes in which the metal charges range from +1.50 to +1.70. Although the spin density of the radical is mainly located at the CAAC ligand, complex 2 reacts as a low‐valent MgI complex: reaction with a I2 solution in toluene gave (Am)MgI⋅(CAAC) (1) as the major product.

Access to a Labile Monomeric Magnesium Radical by Ball-Milling.

In order to isolate a monometallic Mg radical, the precursor (Am)MgI⋅(CAAC) (1) was prepared (Am=tBuC(N‐DIPP)2, DIPP=2,6‐diisopropylphenyl, CAAC=cyclic (alkyl)(amino)carbene). Reduction of a solution of 1 in toluene with the reducing agent K/KI led to formation of a deep purple complex that rapidly decomposed. Ball‐milling of 1 with K/KI gave the low‐valent MgI complex (Am)Mg⋅(CAAC) (2) which after rapid extraction with pentane and crystallization was isolated in 15 % yield. Although a benzene solution of 2 decomposes rapidly to give Mg(Am)2 (3) and unidentified products, the radical is stable in the solid state. Its crystal structure shows planar trigonal coordination at Mg. The extremely short Mg−C distance of 2.056(2) Å indicates strong Mg−CAAC bonding. Calculations and EPR measurements show that most of the spin density is in a π* orbital located at the C−N bond in CAAC, leading to significant C−N bond elongation. This is supported by calculated NPA charges in 2: Mg +1.73, CAAC −0.82. Similar metal‐to‐CAAC charge transfer was calculated for M0(CAAC)2 and [MI(CAAC)2 +] (M=Be, Mg, Ca) complexes in which the metal charges range from +1.50 to +1.70. Although the spin density of the radical is mainly located at the CAAC ligand, complex 2 reacts as a low‐valent MgI complex: reaction with a I2 solution in toluene gave (Am)MgI⋅(CAAC) (1) as the major product.

Physicochemical Characterization of Santa Barbara Amorphous-15 (SBA-15) and Its Functionalization with Polyaniline for Phenol Adsorption

The chemical surface of Santa Barbara Amorphous-15 (SBA-15) was functionalized with polyaniline (SBA-15/PA) and was prepared using aniline and ammonium persulfate as the modifying agent and oxidant. The samples were characterized by N2 physical adsorption at 77 K. SBA-15’s surface area was 654.5 m2 g−1, changing to 254.6 m2 g−1. The total acidity and basicity were determined using a modified Boehm’s method, and the point of zero charge pH (pHpzc) was determined. Immersion calorimetry in water, benzene, and NaOH, HCl, and phenol (100 mg L−1) solutions was performed, producing values ranging from −15.1 to −174.1 J g−1 related to the chemical surface, pHpzc, and acid and base group values. Finally, the phenol adsorption capacity was found to be higher for the modified polyaniline silica, at 138 mg g−1.

Polyvinyl alcohol-polyvinylpyrrolidone-hydroxy apatite (PVA-PVP-Hap) membrane for effective removal of benzene from aqueous solutions:-Kinetic, isotherm, and thermodynamic studies

Benzene is a widely used organic compound that is hazardous to human health and the environment. Exposure to benzene leads to cancer and is also harmful to reproductive organs. Our study deals with the adsorptive removal of benzene from aqueous solutions using Polyvinyl alcohol-Polyvinylpyrrolidone-Hydroxyapatite (PVA-PVP-Hap) membrane. The removal efficiency of the PVA-PVP-Hap membrane was found to be 94.79% with 10 ppm benzene solution at room temperature. The adsorption behavior of benzene on the previously synthesized membrane was analyzed by UV–Visible spectrophotometer at a wavelength of 252 nm. The adsorption mechanism of the composite membrane was analyzed by batch adsorption experiments. The result shows that the adsorption of benzene onto the membrane is best computed by the Freundlich isotherm model and pseudo-second-order kinetic model. The adsorption isotherm study reveals that the adsorption of benzene onto the membrane follows physisorption. Benzene adsorbed PVA-PVP-Hap membrane was successfully regenerated by 2-propanol and 80% removal of benzene was shown by the membrane even after the 6th cycle of regeneration.

Synthesis of Novel Pseudocloso Ruthenacarboranes based on an Unsubstituted nido‐C2B9H112− Ligand

AbstractThe reaction of the known closo‐ruthenacarborane 3‐H‐3‐Cl‐3,3‐(PPh3)2‐closo‐3,1,2‐RuC2B9H11 with tridentade nitrogen‐based ligands of the general formula (C5NH4CH2)2NR (R=H, Me, Et, iPr, But) in benzene solution at 60 °C allowed us to isolate novel ruthenacarborane clusters 3,3,3‐(2’‐NC5H4CH2)2NR‐pseudocloso‐3,1,2‐RuC2B9H11. According to the performed X‐ray study, the obtained compounds are the first examples of pseudocloso‐metallacarboranes bearing unsubstituted C2B92− nido‐carborane ligand. In spite of the determined pseudocloso structure of the complexes in the solid state, the recorded 11B{1H} NMR spectra indicate that some of them are converted into the closo isomers in solution. The conducted quantum‐chemical calculations have confirmed the subtle difference between two configurations and possible rearrangement in solution. The performed electrochemical investigations show the ability of the formed ruthenacarboranes to undergo reversible oxidation to Ru(III) species.

Toxicity assessment and detection of benzene extracted from wastewater by saponin biosurfactant using luminescence biosensor

AbstractIn this research, benzene, a toxic compound encountered in industrial wastewater, was extracted using a mixture of saponin and sodium dodecyl sulfate (SDS) as anionic surfactants. Also, a biosensor system for assessment of toxicity and detection of extracted benzene was designed using the Luc strains of luminescent Escherichia coli. Results showed saponin and SDS were synergistic for the extraction of benzene. An optimal hydrophilic–lipophilic balance value for extraction was determined to be about 24.1, representing a mixture of 40 wt% SDS and 60% saponin. Under optimal conditions, the concentration of extracted benzene in extraction phase reached 27 ppm. When extracted benzene solution was injected into the biosensor system, the luminescence level of biosensor decreased dramatically, reflecting toxicity. The concentration of benzene in the extracted solution correlated well with toxicity levels measured by the biosensor system. Using the luminescence biosensor system, the half‐maximal effective concentration (EC50) value of benzene was about 26.2 ppm. Our results demonstrate that the designed biosensor system has good sensitivity for toxicity assessment of extracted benzene, and therefore can be proposed as an approach to detect of benzene and other toxic compounds in wastewater.

Facial-Meridional Isomerization and Reductive Elimination in [(R2P-o-C6H4)2N]PtMe3 (R = Ph, iPr).

Treatment of PtMe3I in tetrahydrofuran with either in situ prepared [R-PNP]Li ([R-PNP]- = [(R2P-o-C6H4)2N]-; R = Ph, iPr) or H[R-PNP] in the presence of triethylamine at room temperature affords quantitatively fac-[R-PNP]PtMe3. Thermolysis of fac-[R-PNP]PtMe3 in benzene solutions generates mer-[R-PNP]PtMe3 and ultimately [R-PNP]PtMe and ethane. Complexes mer-[R-PNP]PtMe3 represent the first meridional trialkylplatinum(IV) derivatives to date.

Anti-leukemogenic Efficacy of Aloe vera Gel on Benzene-induced Leukemia in Wistar Rats

Backgroud: The toxicity of benzene leading to leukemia induction has been well documented in animal model. Aloe vera is a succulent perennial evergreen flowering plant used traditionally in the treatment of jaundice and was found to have potent cytotoxic effect against HL60 human acute myeloid leukemia. The present study investigated the in vivo chemoprotective effects of Aloe vera gel on benzene-induced leukemia in rats.
 Methodology: Leukemia was induced in male Wistar rats of 80-90g weight by intravenously administered 0.2ml benzene solution alternate days for four weeks. Following induction, leukemic rats and normal baseline control rats were randomly assigned into four experimental groups of 6 animals each as follows: Group CTRL (control), normal baseline control rats; Group AVG (Aloe vera gel), normal baseline rats treated with Aloe vera gel (150 mg/kg) for 7 days, Group LKR (leukemic rats), untreated leukemic rats serving as leukemia control and Group LKR + AVG, leukemic rats treated with Aloe vera gel (150 mg/kg) for 7 days.
 Results: Leukemic rats showed altered hematology and morphological deformations such as anisocytosis, poikilocytosis and blast cells occurrence in peripheral blood. Also hypercellularity, severe dysplasia and significantly elevated micronucleated polychromatic erythrocyte were observed in marrow of leukemic rats. Moreover, benzene caused a significant elevation in plasma level of advanced oxidation protein products (AOPPs) with concomitant reduction in total sulfhydryl and arylesterase activity. However, treatment with Aloe vera gel restored blood hematology to near normal and mitigated the deformities in blood cell morphology induced by benzene. Aloe vera supplementation also effected a disappearance of dysplasia and diminution in the frequency of micronucleus in the bone marrow of treated leukemic rats. It also enhanced plasma antioxidant capability by restoring sulfhydryl content and arylesterase activity of the blood and abrogated the increase in plasma content of AOPPs.
 Conclusion: Overall, Aloe vera gel offered chemoprotective effect on Benzene-induced leukemia in rats.

Syntheses, Magnetic, Spectral and Biological Studies on the Coordination Compounds of N-(2-Hydroxyphenyl)-C-(3′- Carboxy-2′-Hydroxyphenyl) Thiazolidin-4-One

A dry benzene solution of the Schiff base, N-(2-hydroxyphenyl)-3′-carboxy-2′- hydroxybenzylideneimine upon reacting with mercaptoacetic acid undergoes cyclization and forms N- (2-hydroxyphenyl)-C-(3′-carboxy-2′-hydroxyphenyl)thiazolidin-4-one, LH3 (I). A MeOH solution of I reacts with Ni(II) and UO2(VI) ions and forms the monomeric coordination compounds, [Ni(LH)(MeOH)3] and [UO2(LH)(MeOH)]. The coordination compounds have been characterized on the basis of elemental analyses, molar conductance, molecular weight, spectral (IR, reflectance) studies and magnetic susceptibility measurements. I behaves as a dibasic tridentate OOS donor ligand in these compounds. The compounds are non-electrolytes (M = 4.3-6.4 mho cm2 mol-1) in DMF. Octahedral structure for Ni(II) and UO2(VI) compounds are suggested. LH3 (I) and its complexes while testing with E.Coli. (Gram Negative) and S. Aureus (Gram positive) bacteria show antibacterial activities.

Mechanistic Pathways for N2O Elimination from trans-R3Sn-O-N═N-O-SnR3 and for Reversible Binding of CO2 to R3Sn-O-SnR3 (R = Ph, Cy)

The rate and mechanism of the elimination of N2O from trans-R3Sn-O-N═N-O-SnR3 (R = Ph (1Ph) and R = Cy (1Cy)) to form R3Sn-O-SnR3 (R = Ph (2Ph) and R = Cy (2Cy)) have been studied using both NMR and IR techniques to monitor the reactions in the temperature range of 39-79 °C in C6D6. Activation parameters for this reaction are ΔH⧧ = 15.8 ± 2.0 kcal·mol-1 and ΔS⧧ = -28.5 ± 5 cal·mol-1·K-1 for 1Ph and ΔH⧧ = 22.7 ± 2.5 kcal·mol-1 and ΔS⧧ = -12.4 ± 6 cal·mol-1·K-1 for 1Cy. Addition of O2, CO2, N2O, or PPh3 to sealed tube NMR experiments did not alter in a detectable way the rate or product distribution of the reactions. Computational DFT studies of elimination of hyponitrite from trans-Me3Sn-O-N═N-O-SnMe3 (1Me) yield a mechanism involving initial migration of the R3Sn group from O to N passing through a marginally stable intermediate product and subsequent N2O elimination. Reactions of 1Ph with protic acids HX are rapid and lead to formation of R3SnX and trans-H2N2O2. Reaction of 1Ph with the metal radical •Cr(CO)3C5Me5 at low concentrations results in rapid evolution of N2O. At higher •Cr(CO)3C5Me5 concentrations, evolution of CO2 rather than N2O is observed. Addition of 1 atm or less CO2 to benzene or toluene solutions of 2Ph and 2Cy resulted in very rapid reaction to form the corresponding carbonates R3Sn-O-C(═O)-O-SnR3 (R = Ph (3Ph) and R = Cy (3Cy)) at room temperature. Evacuation results in fast loss of bound CO2 and regeneration of 2Ph and 2Cy. Variable temperature data for formation of 3Cy yield ΔHo = -8.7 ± 0.6 kcal·mol-1, ΔSo = -17.1 ± 2.0 cal·mol-1·K-1, and ΔGo298K = -3.6 ± 1.2 kcal·mol-1. DFT studies were performed and provide additional insight into the energetics and mechanisms for the reactions.

Influence of the solvent on the Lewis acidity of antimony pentahalides and group 13 Lewis acids toward acetonitrile and pyridine.

Energetic effects of solvation of SbF5 , SbCl5 , and 21 group 13 Lewis acids (LA) and their molecular complexes with acetonitrile and pyridine are evaluated using SMD approach. Compared to the gas phase, solvation increases the stability of boron- and aluminum-containing complexes but decreases the stability of gallium and indium-containing homologs due to larger solation energies of free LA. New Lewis acidity scales, based on the Gibbs energy of dissociation of the molecular complexes LA·pyridine and LA·acetonitrile in the gas phase, in benzene and acetonitrile solutions, are proposed.