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Amine dehydrogenases (AmDHs) are one of the key emerging enzymes used in the synthesis of various amines with the expense of only one ammonium ion as an amino donor, thereby, generates only water molecule as a by-product. Currently, most available AmDHs have been created through protein engineering using the existing natural L-amino acid dehydrogenase, and native AmDHs are rarely reported. In this study, a novel native AmDH from Laribacter hongkongensis (LhAmDH) was identified based on the GenBank database using a sequence-driven approach. LhAmDH showed a good activity towards various carbonyl compounds such as cyclohexanone (170 mU/mg) and isovaleraldehyde (214 mU/mg). The reductive amination of model substrate, cyclohexanone (up to 100 mM) into cyclohexylamine was successfully performed in LhAmDH and FDH system with > 99% conversion using Escherichia coli whole-cell as well as purified enzymes. Furthermore, three enzymes cascade (ω-transaminase, LhAmDH, and FDH) was designed to produce chiral amine from the corresponding ketone using inexpensive ammonium formate as sole sacrificial agent. The active site of LhAmDH residues were predicted using the protein structure homology model building program SWISS-MODEL server. In the docking analysis, cyclohexanone is well-orientated with −5.4 kcal/mol of binding energy and 3.16 A distance from side chain of E104, which is a key residue for interacting ammonia and substrate. This LhAmDH model can be used as a promising template to produce chiral amines through semi-rational design.

Herein, the catalytic performance of palladium nanoparticles grafted on the polymeric TSNH2 (Tentagel-S-NH2) resin was investigated for continuous-flow liquid-phase hydrogenation of two industrially relevant chemicals: 2-methyl-3-butyn-2-ol and nitrocyclohexane. We investigated the effect of process parameters such as temperature and pressure on PdTSNH2 activity and selectivity. Depending on the reaction conditions, well-dispersed PdNPs with average size of about 2 nm have shown very high flexibility in terms selectivity toward the desired products: 2-methyl-3-buten-2-ol or 2-methyl-2-butanol in the case of 2-methyl-3-butyn-2-ol hydrogenation and cyclohexanone oxime or cyclohexylamine as the main product in the case of nitrocyclohexane conversion. The optimal reaction conditions for 2-methyl-3-buten-2-ol formation were estimated at 25 °C and 5 bar, and in the case of cyclohexanone oxime formation at 40 °C and 10 bar. We demonstrated the general trend in the catalytic performance of 2.2 wt% Pd grafted on Tentagel-S-NH2. Independently of the hydrogenated substrate, the increase in conversion leads to decreased selectivity to 2-methyl-3-buten-2-ol and cyclohexanone oxime at the expense of increasing the selectivity to 2-methyl-2-butanol or cyclohexylamine. Graphic abstract

Several protonated amine-templated uranyl oxalate complex were designed and synthesized, and the structures and optical properties were investigated by different techniques. The amine templates have a significant structural-oriented effect on the construction of uranyl oxalate complex. When alkyl substituents are added to N atoms, templated amines will be more flexible and helps build the crystals with a denser structure and a better thermal stability. The crystal properties are closely related to the amine templates: 4# (using N,N-diethylcyclohexylamine as the template) has a potential application as CO gas storage materials; 1# (using cyclohexylamine as the template) has a potential application for ultraviolet irradiation chemical dosimeter.

In this work, a new mesoporous silicon sulfonic acid catalyst derived from silicic acid has been successfully prepared by the chemical bonding method. The physico-chemical properties of mesoporous silicon sulfonic acid catalysts have been systematically characterized using various techniques. The results demonstrate that sulfonic acid groups have been grafted on silicic acid by forming a new chemical bond (Si-O-S). The mesoporous silicon sulfonic acid exhibits excellent catalytic performance and stability in the vapor phase hydroamination reaction of cyclohexene with cyclohexylamine. Cyclohexene conversion of 61% and 97% selectivity to dicyclohexylamine was maintained after running the reaction for over 350 h at 280 °C. The developed mesoporous silicon sulfonic acid catalyst shows advantages of low cost, superior acid site accessibility, and long term reactivity stability. Moreover, a possible catalytic hydroamination reaction mechanism over silicon sulfonic acid was suggested. It has been demonstrated that the sulfonic acid groups of the catalyst play an important role in the hydroamination. The present work provides a simple, efficient, and environmentally friendly method for the hydroamination of cyclohexene to valuable dicyclohexylamine, which also shows important industrial application prospects.

Thickener formulation plays a significant role in the performance characteristics of grease. The polyurea greases (PUGs) were synthesized using mineral oil (500SN) as the base oil, and by regulating the reaction of diphenylmethane diisocyanate (MDI) and different organic amines. The as-prepared PUGs from the reaction of MDI and cyclohexylamine/p-toluidine exhibit the optimum physicochemical and friction-wear properties, confirming that the regulation of thickener formulation can improve the performance characteristics of grease, including friction reduction, wear, corrosion resistance, and load-carrying capacity. The anti-corrosion and lubrication properties of as-prepared PUGs depend on good sealing functions and a boundary lubrication film (synergy of grease-film and tribo-chemical reaction film), as well as their chemical components and structure.

Reactions of 2-[1-ethyl-3-methyl-7-(thietan-3-yl)- and 2-[1-ethyl-3-methyl-7-(1,1-dioxothietan-3-yl)xanth- 8-ylthio]acetic acids with amines (diethylamine, monoethanolamine, diethanolamine, triethanolamine, piperidine, cyclohexylamine, and benzylamine) gave 42 – 89% yields of 2-[1-ethyl-3-methyl-xanth-8-ylthio]- acetate salts containing thietanyl and dioxothietanyl rings. The structures of the synthesized compounds were confirmed using IR and PMR spectroscopy. The synthesized compounds exhibited anti-aggregation activity.

In the present study, an elevated temperature homogeneous liquid extraction coupled with ionic liquid‑based dispersive liquid–liquid microextraction was developed to extract five carbamate pesticides (pirimicarb, carbaryl, methiocarb, aldicarb, and carbofuran) from packed fruit juice samples. The method consisted of a two-step procedure in which cyclohexylamine was used in order to extract the target analytes. In the first step, the analytes were extracted from a sample solution thermostated at elevated temperature (80 °C) into a water-immiscible organic solvent (cyclohexylamine). In the second step, the separated organic phase was mixed with 1-butyl-3-methylimidazolium chloride (as the solvent for extraction) and the mixture was spread into deionized water. In this step, cyclohexylamine controlled the solubility of 1-butyl-3-methylimidazolium chloride in the aqueous phase and acted as a dispersive solvent and a phase separation agent, simultaneously. After centrifugation, we removed all the gathered organic phases and analyzed them by using high-performance liquid chromatography diode-array detector. Figure of merits of the method including the limits of detection and quantification, enrichment factors, extraction recoveries, and relative standard deviations were obtained within ranges 0.4–3.9 and 1.5–13.2 ng mL−1, 147–217, 59–87%, and 3.3–5.5%, respectively, indicating that the method was successful in determining the analytes.

In this work, we investigated the host ability of TETROL [(+)-(2R,3R)-1,1-4,4-tetraphenylbutane-1,2,3,4-tetraol] in the presence of two guest series, namely saturated cyclohexanone, cyclohexanol and cyclohexylamine on the one hand, and aromatic/saturated combinations of aniline, cyclohexylamine, phenol and cyclohexanol on the other. TETROL formed complexes with all of these guests in single solvent experiments, while mixed complexes were obtained when the host was recrystallized from guest mixtures. However, most notably, TETROL showed enhanced selectivities for the amino-containing cyclic organic compounds compared with the ketone and alcohol, results of which allude to the potential of purifying various combinations of such compounds through host‒guest chemistry. We conducted single crystal X-ray diffraction experiments in order to reveal the underlying reasons for the selectivity displayed by TETROL for these amines.

The present work is aiming to utilize Re based catalysts for hydrodenitrogenation (HDN) of cyclohexylamine over SBA-15 supported catalyst under optimized conditions. Siliceous SBA-15 was synthesized by hydrothermal method and used as a support for Re catalysts with different Re loadings (1, 3, 5 and 7 wt%). The supported catalysts were characterized by various physico-chemical techniques like XRD, N2-sorption studies, UV-DRS, FE-SEM, HR-TEM, NH3-TPD, Raman spectroscopy and XPS (sulfided catalyst). The oxide catalysts were presulfided before the hydrodenitrogenation reaction using ditertiary butyl polysulfide (DBPS) as sulfiding agent and hydrogen. The catalytic activity of the sulfided catalysts was tested for HDN of cyclohexylamine. A high HDN activity was observed on 5 wt% Re loaded SBA-15 catalyst. The catalytic activity was correlated with characterization results.

A new sample preparation method, cyclohexylamine-based heat-induced homogeneous liquid–liquid microextraction, has been developed for the extraction and preconcentration of Cd(II) and Zn(II) ions in edible oils followed by flame atomic absorption spectrometry determination. First, the analytes are extracted into an acidic solution (a balanced mixture of HNO3 and HCl). Second, they are preconcentrated via the microextraction method. Accordingly, cyclohexylamine (as a complexing agent and an extraction solvent) is added at µL-level into the obtained solution containing the analytes to form a homogeneous solution followed by the addition of sodium chloride. After manual shaking, the obtained solution is placed in a water bath thermostated at 60 °C. A cloudy solution because of the decrease in cyclohexylamine solubility in water at high temperature is formed. After centrifuging fine droplets of cyclohexylamine containing Cd(II) and Zn(II)—cyclohexylamine complexes are collected on the top of the aqueous phase. The preconcentrated analytes in the upper phase by use of flame atomic absorption spectrometry are analyzed and determined. Several variables possibly affecting the extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration curves were linear in the ranges of 10–300 and 2.5–200 µg kg− 1 for Cd(II) and Zn(II), respectively. Repeatability of the proposed method, expressed as relative standard deviation, was obtained 2.4 and 1.7% for Cd (II) and Zn(II), respectively. Moreover, the detection limits of the selected analytes were obtained 3.8 and 0.6 µg kg− 1 for Cd(II) and Zn(II), respectively.

WOS: 000446500100013 Sulfenamide and its derivatives (S-N bond) have been synthesized with classical method in the literature. However, microwave-assisted synthesis of a series of N-(substituted phenylthio), N-(benzylthio), N-(cyclothio), and N-(2-mercaptobenzimidazolyl)amines has been not in the literature yet. They have been obtained from treating some amines (4 mmol) with thioph-thalimides (PhthSR, 1 mmol) using sulfur transfer reagent in the presence of 2-ethoxyethanol (beta-ee, neat) under microwave irradiation at 50 degrees C. The scope of this reaction was shown by the efficient synthesis of sulfenamides in good to excellent yields of 70-98% under free catalyst and ligand. Nine of the synthesized sulfenamide derivatives are novel. All of the thiols react with morpholine to give corresponding sulfenamides in excellent yields of 78-98%. Thiophenol, 4-methylthiophenol, 4-chlorothiophenol, and 4-fluorothiophenol react with cyclohexylamine to give corresponding sulfenamides in high yields 81-92%. Thiophenol, 4-methylthiophenol, 4-chlorothiophenol react with pyrrolidine to give corresponding sulfenamides in good yields of 70-76%. We observed that the reaction of t-butylamine with N-(phenylthio)phthalimide gave desired sulfenamide under microwave irradiation in the presence of DPPH as radical scavenger reagent in high yield of 93% Aniline, benzylamine, 1-hexylamine, ethanolamine, diethylamine, N-ethyl-n-butylamine, N-ethylaniline, N-benzylmethylamine, t-butylamine react with thiols to give symmetrical disulfides instead of desired products under microwave irradiation, 2-ethoxyethanol as a solvent (neat), and at 50 degrees C. In this study, microwave-assisted synthesis method was compared with the classical method. All the products obtained were purified with chromatographic method and the analysis of these products was confirmed with IR, H-1 NMR, C-13 NMR spectroscopy, MS spectrometry, and elemental methods. [GRAPHICS] . Ondokuz Mayis UniversityOndokuz Mayis University [PYO.FEN.1904.10.024] We would like to thank Ondokuz Mayis University (Grant No. PYO.FEN.1904.10.024) for its financial support of this work.

3-Methyl-7-(1,1-dioxothietan-3-yl)-8-cyclohexylamino-1-ethyl-1H-purine-2,6(3H,7H)-dione was synthesized via the reaction of 8-bromo-3-methyl-7-(1,1-dioxothietan-3-yl)-1-ethyl-1H-purine-2,6(3H,7H)-dione and cyclohexylamine and exhibited antidepressant activity that was most pronounced at a dose of 1.6 mg/kg.

The chemistry of 4,6-dialkyl-2-amino-1,3,5-triazines with bulky alkyl substituents was investigated and their use as building blocks for preparing chiral thiourea organocatalysts explored. Reaction of ammonia with 4,6-di-tert-butyl-2-chloro-1,3,5-triazine gave 4,6-di-tert-butyl-1,3,5-triazin-2-amine which formed extended hydrogen-bond networks in the solid state according to X-ray crystallography. Selected heterocyclic amines were converted to isothiocyanates, and the latter reacted with (S,S)-2-(dimethylamino)cyclohexylamine to give enantiopure 1-hetaryl-3-[2-(dimethylamino)cyclohexyl]thioureas, with hetaryl representing either 4,6-dimethyl-1,3-diazin-2-yl, 4,6-diisopropyl-1,3,5-triazin-2-yl, or 4,6-di-tert-butyl-1,3,5-triazin-2-yl groups. These compounds are structural analogs of Takemotos’s chiral thiourea organocatalysts (1-[3,5-bis(trifluoromethyl)phenyl]-3-[(1S,2S)-2-(dimethylamino)cyclohexyl]thiourea) with an aza-aryl instead of the 3,5-bis(trifluoromethyl)phenyl group. They feature a strong intramolecular N–H to N-1 hydrogen bond, as shown by X-ray crystallography of 1-(4,6-di-tert-butyl-1,3,5-triazin-2-yl)-3-[2-(dimethylamino)cyclohexyl]thiourea in the solid state and by 1H NMR spectroscopy of all derivatives in CDCl3 solution, which prevents them from acting as bifunctional organocatalyst. In the reaction of 4,6-di-tert-butyl-2-chloro-1,3,5-triazine with ammonia, 4,6-di-tert-butyl-2-ethoxy-1,3,5-triazine was identified as side-product displaying a mildly sweet, floral odor that is unusual for a 1,3,5-triazine. Analogs (>35) of 4,6-di-tert-butyl-2-ethoxy-1,3,5-triazine were prepared to define the important structural factors of the olfactophore.

The oxidation of cyclohexylamine with molecular oxygen over a heterogeneous catalyst is an attractive one-step route to prepare a commercially important cyclohexanone oxime. The effect of the reaction conditions on the conversion of cyclohexylamine during its oxidation by molecular oxygen and on the selectivity of cyclohexanone and cyclohexanone oxime formation was investigated over heterogeneous catalysts (alumina and alumina supported silicotungstic acid). The present work is aimed at the enhancement of the cyclohexanone oxime yield, for which the optimized conditions were found as: reaction temperature of 180 °C, LHSV of cyclohexylamine 1 ml g−1 h−1, oxidant 33 % O2 in nitrogen with a total GHSV of 24 ml min−1. Cyclohexanone, formed from cyclohexylamine, reacts with cyclohexylamine to N-cyclohexylidenecyclohexylamine, their Schiff base. The most intense formation of cyclohexanone was observed in the initial period of the catalytic tests. Carbonaceous deposits, responsible for the catalyst deactivation, are formed mainly from the Schiff base; their amount increases by time on stream, and the rate of their formation correlates with the concentration of oxygen in the reaction mixture, as well as with the formation rate of cyclohexanone and the Schiff base. Injection of water to the reactant stream prolongs the catalyst lifetime and reduces the tar formation. However, it deteriorates the catalyst´s activity and selectivity. The supposed mechanism of cyclohexylamine oxidation is discussed.

A catalyst-free greener protocol for the most effective one-pot synthesis of 2,6-diamino-4-aryl-1-propyl/cyclohexyl-1,4-dihydropyridine-3,5-dicarbonitrile derivatives has been developed using a simple three-component reaction of structurally diverse aldehydes, malononitrile and n-propylamine/cyclohexylamine at an ambient temperature. The formation of 1,4-dihydropyridines could be achieved in aqueous methanol in a single synthetic process involving no chromatography. The newly synthesized highly functionalized 1,4-DHPs have been screened for their in vitro antioxidant activity using the DPPH radical scavenging technique and the results were good in comparison with a standard drug.

Substitution of the aqua ligand from three platinum(II) complexes, namely [Pt(H2O)(N,N-bis(2-pyridylmethyl)cyclohexylamine](ClO4)2 (Pt1); [{Pt(H2O)}2(N,N,N′,N′-tetrakis(2-pyridylmethyl)-trans-1,4-cyclohexyldiamine)](ClO4)4 (Pt2); and [{Pt(H2O)}2(N,N,N′,N′-tetrakis(2-pyridylmethyl)-4,4′-ethylenedicyclohexyldiamine)](ClO4)4 (Pt3), by three biologically relevant nucleophiles [viz., glutathione (Glu); DL-penicillamine (Pen); and l-histidine (His)] was studied in aqueous 0.1 M perchloric acid medium. The substitutions were investigated under pseudo-first-order conditions as a function of nucleophile concentration and temperature using UV–visible spectrophotometry. The reactions of these complexes with the nucleophiles proceeded via a single step whose reactivity decreased in the order: Pt1 > Pt3 > Pt2 and was controlled by steric and electronic influences of the complexes. Sulfur donor nucleophiles (Glu and Pen) reacted much faster than the nitrogen bearing His, with Glu appearing to be more nucleophilic than Pen. The large and negative activation entropies and low but positive enthalpies of activation affirm an associative mode of activation.

The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson reagent) with isobutanol, cyclohexylamine and phenylethylamine produced (4-methoxy-phenyl)-phosphonodithioic acid o-isobutyl ester HS2P(p-C6H4OMe) (OCH2CH(CH3)2) (I), [S2P(C6H11NH)(p-C6H4OMe) H3N+C6H11] (II) and [S2P(phCH2CH2NH) (p-C6H4OMe)H3N+CH2CH2ph] (III), respectively. The reaction of alcohol with Lawesson reagent produced neutral product (I) while that with amines led to an ion pair (II, III). Furthermore, reaction of I, II and III with NiCl2.6H2O in methanol produced novel complexes: IV, V and VI. The compounds were characterized by 1H, 13C and 31P NMR, IR spectroscopy and elemental analysis. The single crystal X-ray structures of IV and V showed that the nickel complexes are square planar. Compound V formed a three-dimensional supramolecular structure via intermolecular P–O …H–N hydrogen bonds. The X-ray crystallography of V showed that those three hydrogens of + NH 3 cation produced three hydrogen bonds with different distances. The new compounds were additionally tested in view of their anti-bacterial properties. The ligands containing amine substituents exhibited more activity toward tested bacteria than their alcohol substituents, while the Ni(II) complexes including alcohol substituents exhibited high potential.

Four compounds, [(HL) 3 3+ · (cba−)3·2H2O] (1, cba = o-chlorobenzoate), [(HL)+·(NSA−)] (2, NSA− = 5-nitrosalicylate), [(HL) 2 2+ ·(3,5-dns2−)] (3, 3,5-dns2− = 3,5-dinitrosalicylate), and [(HL) 2 2+ ·(nda2−)] (4, nda2− = 1,5-naphthalenedisulfonate) were obtained from self-assembly of the corresponding acids with the cyclohexylamine, and their structures were fully characterized. All four compounds are organic salts, with proton transfer occurring to the NH2 of the cyclohexylamine moiety. All structures adopted hetero supramolecular synthons. Compound 1 crystallizes in the triclinic, space group P-1, with a = 10.151(3) A, b = 13.160(4) A, c = 17.172(5) A, α = 72.159(4)°, β = 79.546(4)°, γ = 78.285(4)°, V = 2120.5(11) A3, Z = 2. Compound 2 crystallizes in the monoclinic, space group P2(1)/c, with a = 13.501(2) A, b = 6.3144(15) A, c = 19.601(3) A, β = 123.900(13)°, V = 1386.9(4) A3, Z = 4. Compound 3 crystallizes in the monoclinic, space group P2(1)/n, with a = 14.6439(11) A, b = 6.9231(4) A, c = 21.3012(18) A, β = 96.4800(10)°, V = 2145.7(3) A3, Z = 4. Compound 4 crystallizes in the monoclinic, space group P2(1)/n, with a = 5.3477(5) A, b = 19.9238(16) A, c = 11.1761(9) A, β = 95.7230(10)°, V = 1184.84(17) A3, Z = 2. Analysis of the crystal packing of 1–4 displays that there are extensive N–H···O hydrogen bonds between the acids and the cyclohexylamine in all of the salts. Except the classical hydrogen bonding interactions, the secondary propagating interactions also play significant roles in structure extension. The four salts displayed 2D/3D framework structures for the synergistic effect of the various noncovalent interactions. The crystal structures of the cyclohexylamine salts with o-chlorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, and 1,5-naphthalenedisulfonic acid show extensive classical hydrogen bonding as well as C–H···O, CH2···O, Cl···O, NH3···π, CH2···π, and π···π interactions, giving 2D sheets or 3D networks.

A cyclohexylamine oxidase (CHAO) of bacterial origin was previously shown to be a potentially useful catalyst in the deracemization of racemic primary amines. To further explore the properties and application of this enzyme, five single-amino acid substitution mutants (L199A, M226A, Y321A, Y321F, and L353M) were created based on superimposition of the tertiary structure of CHAO and the monoamine oxidase (MAO) B homolog. The substrate specificity of the purified wild-type and five mutant enzymes were examined towards 38 structurally diverse amines. All the enzymes exhibited better activity for primary amines than secondary and tertiary amines and in general exhibited high stereoselectivity. Among the mutant enzymes, M226A displayed an enhanced activity (5-400 %) towards most substrates, and L353M showed 7-445 % higher activity towards primary aliphatic amines with cycloalkane or aromatic moieties. Kinetic parameters revealed that both Y321 mutants showed higher catalytic efficiency towards cyclooctanamine, whereas the wild-type CHAO (wt CHAO) was most efficient towards cyclohexylamine. The wt CHAO or variant L353M in combination with a borane-ammonia complex as reducing agent was applied to the deracemization of 1-aminotetraline to give the (R)-enantiomer, a precursor of an antidepressant drug Norsertraline, in good yield (73-76 %), demonstrating their application potential in chiral amine synthesis.

A series of CuFe2O4 nanoparticles was synthesized with the assistance of organic amines or inorganic bases via a hydrothermal method. The prepared samples were confirmed as a spinel-type structure by x-ray diffraction. The shapes of the samples were detected by transmission electron microscope (TEM), which confirmed that all the synthesized samples were nanoparticles. The electrocatalytic properties of the samples modified on a glassy carbon electrode were investigated for the reduction of p-nitrophenol, potassium chromate (K2CrO4), and sodium nitrite (NaNO2) in basic solution using the cyclic voltammetry method. The results showed that all the samples showed enhanced catalytic activity for the reduction of p-nitrophenol, K2CrO4, and NaNO2. Among the samples, CuFe2O4 prepared with cyclohexylamine (S-2) showed the highest catalytic activity for p-nitrophenol reduction, whereas CuFe2O4 prepared with NaOH and PVP (S-4) showed the highest activity for both K2CrO4 and NaNO2 reduction in basic solution.

A new compoud based on carbazole functionalized β-diketone-boron difluoride (1) was synthesized. It is found that compoud 1 can gel toluene, ethylbenzene and some mixed solvents, and 3D networks consisting lots of nanofibers were observed using SEM and fluorescence microscopy. The molecular packing model in xerogel 1 was proposed according to the results of XRD, UV/Vis absorption and semiempirical calculations. The obtained nanofibers prepared through organogelation can emit strong orange light under irradiation. It is interesting that the fluorescence of the nanofiber-based film can be quenched quickly and significantly upon exposed to the vapors of n-butylamine, dibutylamine, triethylamine, triethylamine, cyclohexylamine, aniline and pyridine instead of other common reagents. Notably, the response time of the nanofiber-based film to aniline vapor reached ca. 0.59 s, and the detection limit for aniline was as low as ca. 0.83 mL/m3.

Co(Cyclohexylamine)2Ni(CN)4 and Cd(Cyclohexylamine)2Ni(CN)4 host compounds have been prepared in powder form. The spectral data suggest that these complexes are similar in structure to the Hofmann-dma-type hosts. The sorption processes of the aromatic guests (benzene, toluene, o-, m-, p-xylene, naphthalene, 1,2-, 1,3-dichlorobenzene and 1,4-dibromobenzene) inthese hosts have been examined at room temperature by gravimetric and spectroscopic measurements. The desorption of the benzene guest against time has been measured. The host structures change on inclusion of the guests and recover after liberation. The host complexes have been suggested as sorbents for isomeric separations.

A convenient procedure has been developed for preparation of amine-substituted or monomethylamine-substituted alkyl/arylurea derivatives. The method comprises two steps—reaction of an alkyl/aryl amine with chlorocarbonylsulfenyl chloride in a non-polar solvent to produce an alkyl/arylcarbonylsulfenyl chloride, then reaction of this alkyl/arylcarbonylsulfenyl chloride with ammonia or monomethylamine in a two-phase reaction with a phase-transfer catalyst, to produce the corresponding alkyl/aryl-substituted urea. R 1 , R 2 : H, methyl, ethyl, propyl, butyl, benzyl, cyclohexyl; R 3 : H, methyl. A simple, one-pot, rapid, efficient, cost-effective, non-phosgene route for synthesis of alkyl/arylurea derivatives starting with the corresponding alkyl/aryl amine and chlorocarbonylsulfenyl chloride.

Several transition metal oxides, including α-Fe2O3, Fe3O4, Co3O4, NiO, CuO and ZnO, were synthesized via an easily controlled hydrothermal method at assistance of organic amine (cyclohexylamine or triethylamine). The synthesized samples were identified and characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), High-resolution Electron Microscopy (HR-TEM), Field Emission Scanning Electron Microscopy (FE-SEM), N2 adsorption/desorption measurement. The resultant metal oxides displayed various morphologies in shape. The as-prepared samples were used as electrocatalysts (CuO was excluded) modified on a glassy carbon electrode for p-nitrophenol reduction in a basic solution. Fe3O4 and Co3O4 samples showed higher catalytic activities.

Activity and selectivity of supported Ni, Pt, and Pd catalysts were studied in the liquidphase reductive amination of cyclohexanone at temperatures ranging from 100 to 150 °C. The catalyst 20% Ni/SiO2 is most active and selective providing a maximum yield of cyclohexylamine. The influence of the reaction conditions on the parameters of the catalytic process was studied. A detailed analysis of the reaction products was carried out using 13C NMR spectroscopy and gas chromatography coupled with mass spectrometry (GC-MS). This made it possible to refine the reaction mechanism and to identify a new by-product earlier unknown in the literature.

The original version of this article unfortunately contained a mistake in the Fig. S1 of supplementary material. It is corrected with this erratum.

Densities and viscosities were measured for the binary mixtures of cyclohexylamine and cyclohexanone with butyl acetate, butanone, butylamine, tert-butylamine, and 2-butoxyethanol at 298.15 K over the entire composition range. From density data, the values of the excess molar volume (V E) have been calculated. The experimental viscosity data were correlated by means of the equation of Grunberg–Nissan. The density and viscosity data have been analyzed in terms of some semiempirical viscosity models. The results are discussed in terms of molecular interactions and structural effects. The excess molar volume is found to be either negative or positive depending on the molecular interactions and the nature of the liquid mixtures and is discussed in terms of molecular interactions and structural changes.

The formation of 3-(1-piperidinyl)alanyl-containing peptides via phosphoryl β-elimination was identified from the application of Fmoc-Ser(PO3Bzl,H)-OH in peptide synthesis as shown by RP-HPLC, ES-MS and 31P-NMR analysis. An N α -deprotection study using the model substrates, Fmoc-Xxx(PO3Bzl,H)-Val-Glu(OtBu)-Resin (Xxx = Ser, Thr or Tyr) demonstrated that piperidine-mediated phosphoryl β-elimination occurred in the N-terminal Ser(PO3Bzl,H) residue at a ratio of 7% to the target phosphopeptide, and that this side reaction did not occur in the corresponding Thr(PO3Bzl,H)- or Tyr(PO3Bzl,H)- residues. The generation of 3-(1-piperidinyl)alanyl-peptides was also shown to be enhanced by the use of microwave radiation during Fmoc deprotection. An examination of alternative bases for the minimization of byproduct formation showed that cyclohexylamine, morpholine, piperazine and DBU gave complete suppression of β-elimination, with a 50% cyclohexylamine/DCM (v/v) deprotection protocol providing the crude peptide of highest purity. Piperidine-induced β-elimination was found only to occur in Ser(PO3Bzl,H) residues that were in the N-terminal position, since the addition of the next residue in the sequence rendered the phosphoseryl residue stable to multiple piperidine treatments. The application of the alternative N α -deprotection protocol using 50% cyclohexylamine/DCM (v/v) is therefore recommended for deprotection of the Fmoc group from the Fmoc-Ser(PO3Bzl,H) residue, with particular benefit anticipated for the synthesis of multiphosphoseryl peptides.

The complex formation of cucurbit[6]uril with cyclohexylmethylamine hydrochloride and hexylamine hydrochloride has been studied in aqueous solution using potentiometric titrations. The influence of salts like NaCl, KCl, RbCl, CsCl, BaCl2 and tetramethylammonium chloride and tetraethylammonium perchlorate on the complex formation with amines has been studied at different concentrations of these salts. With increasing salt concentration the stability constants for the complex formation with cyclohexylamine hydrochloride and hexylamine hydrochloride decreases. However, no specific influence is observable. These results show that 2:1 complexes between these salts and cucurbituril are not formed or that their concentration in solution is rather low.

Nanoscale blending of aromatic and aliphatic polyimides has been attempted by employing corresponding poly(amic acid) precursors in order to elucidate clues for achieving a semi-molecular composite film. Pyromellitic dianhydride (PMDA) and 4,4’-oxydianiline (ODA) were used to make the precursor polymer of aromatic polyimide (PMDA-ODA PI) as a semi-rigid rod-like component, whilst bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BOCA) and 4,4’-methylenebis(cyclohexylamine) (MCA) were used to prepare the precursor of aliphatic polyimide (BOCA-MCA PI) as a flexible coil-like component. The weight ratio of aromatic to aliphatic polyimides was varied from 100:0: to 0:100 by 10 wt % gap for monitoring the critical composition upon nanostructure changes. The micro/nanostructure of composite films was characterized by using small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD), while the evolution and thermal property of semi-molecular composites were studied by using FT-IR spectroscopy and dynamic mechanical thermal analysis (DMTA). The result showed that the composite films exhibited a single glass transition behavior, which is ascribed to the molecular level mixing, in the presence of copolyimide fractions.

ZnO nanorods were prepared via a hydrothermal reaction in a solution containing Zn(NO3)2⋅6H2O, NaOH, cyclohexylamine, ethanol and water, and their NO2 and CO sensing behaviors were investigated. The morphology and agglomeration of ZnO nanorods could be manipulated by controlling the amount of water in the solution, which was explained by the variation in the [OH−] due to an interaction between the water and cyclohexylamine. Sea-urchin-like and well-dispersed ZnO nanorods were prepared at low and high water content, respectively. Well-dispersed ZnO nanorods showed 1.8 fold change in resistance at 1 ppm NO2 while there was no significant change in resistance at 50 ppm CO. The present ZnO nanorods can be used in automated car ventilation systems to detect NO2 in the presence of CO.

Porous clay heterostructures (PCHs) are quite a new class of solid acids, and exhibited pore sizes in the rarely observed supermicropore to small mesopore region. They are formed by the surfactant-directed assembly of mesostruc- tured silica within the two dimensional galleries of smectite layered silicates. The acid activation of the smectite clay was an effective way to improve the acidity and the mesoporos- ity of the raw clay mineral. We have studied the effect of the type of clay minerals on the properties of porous acid- activated clay heterostructures (PACHs). Three different raw clays with different cation exchange capacities were selected and acid-activated at an acid/clay ratio of 0.2 (w/w). The syn- thesis of PACHs was achieved and characterized by powder x-ray diffraction, nitrogen adsorption-desorption and acid- ity using cyclohexylamine as probe molecule. A short order in the structure, as revealed by the powder x-ray diffrac- tion of PACH materials was observed, with higher surface areas, pore volumes and acidity for some clays. These prop- erties were not enhanced as we expected, and compared to the PCHs, indicating that the origin or type of clay affects the final properties of the derived materials. By using a soft extraction of the surfactants via chemical way, the stability and the properties of PCH and PACH materials were not improved except for one type of clay.

2-(p-hydroxyphenyl)cyclohexylamides were synthesized from ω-chlorocarboxylic acids using the Ritter reaction. Subsequent reduction under the action of LiAlH4 led to the corresponding substituted cyclic amines. The acute toxicity, analgesic properties, and antidepressant activity of the synthesized compounds were studied and their action on locomotion and exploration activity in the open-field test was evaluated.

Zinc enolates formed from 1-aryl-2-bromo-2-phenylethanones and zinc react with dimethyl 2-(1-arylmethylene)malonates to afford dimethyl 2-(1,3-diaryl-3-oxo-2-phenylpropyl)malonates. The latter react with cyclohexylamine, piperidine, or morpholine to give the corresponding monosubstituted amides. The zinc enolate derived from 2-bromoindanone and zinc reacts with dimethyl 2-(4-bromobenzylidene)malonate, yielding dimethyl 2-[(4-bromophenyl)(1-oxoindan-2-yl)methyl]malonate. The final products largely form as a single diastereomer.

Three novel vic-dioximes: cyclohexylamine-p-tolylglyoxime (L1H2), t-butylamine-p-tolylglyoxime (L2H2) and sec-butylamine-p-tolylglyoxime (L3H2) were prepared by the reaction of anti-p-tolylchloroglyoxime with cyclohexylamine, t-butylamine and sec-butylamine in absolute THF. The detection of H-bonding in all of the Ni(II) complexes by i.r. revealed the square-planar MN4 coordination of mononuclear complexes. MN4 coordination of the [(L1H)2Ni] complex was also determined by 1H and 13C-n.m.r spectroscopy. Mononuclear complexes with a 1:2 metal-ligand ratio were prepared using Ni(II) salts. All Ni(II) complexes are insoluble in common solvents. The ligands and complexes were characterized by elemental analyses, FT-i.r., u.v.–vis., 1H and 13C-n.m.r. spectra, magnetic susceptibility measurements, thermogravimetric analyses (t.g.a.) and cyclic voltammetry.

Zinc enolates generated from 1-aryl-2-bromoalkanones and zinc react with dimethyl 2-(1-arylmethylene)malonate to form dimethyl 2-(2-alkyl-1,3-diaryl-3-oxopropyl)malonates. The latter react with benzylamine or cyclohexylamine to form the corresponding disubstituted amides, while the reactions with piperidine, morpholine, and p-methoxyaniline provide monosubstituted amides of the corresponding target derivatives.

A flow-injection system with differential spectrophotometric detection is proposed for the simultaneous determination of aniline and cyclohexylamine based on their reaction with 1,2-naphthoquinone-4-sulfonate (NQS). The pH is chosen to achieve selectivity since only aniline reacts at acidic pH whereas the two amines are derivatized in basic medium. The flow manifold comprises two reactors and two detection cells for developing and monitoring the reaction under selective and general (non-selective) conditions. A double beam spectrophotometer is used for differential detection, with two flow cells placed in the sample and reference holders. Figures of merit such as sensitivity, linear range, detection limit and precision are established. The evaluation of accuracy using a series of synthetic mixtures indicates overall prediction errors of 3% and 5% for aniline and cyclohexylamine, respectively. The method is applied to the determination of amine impurities in commercial sweeteners. Good concordance between the proposed and the standard chromatographic methods is found.

Three new chelate zinc complexes with azomethine groups characterized by luminescence in the visible spectral region were synthesized: bis(N-(2-oxybenzylidene)cyclohexylamine)zinc, bis(N-(2-oxybenzylidene)-4-tert-butylaniline)zinc, and N,N′-bis(oxybenzylidene)-1,2-phenylenediaminezinc. Their spectral properties were studied. Based on these complexes, we prepared electroluminescence devices giving an intense emission in the blue, green, and red spectral regions.

Zinc enolates derived from 1-aryl-2-bromoalkanones react with alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates to give alkyl 4-(1-alkyl-2-aryl-2-oxoethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates. Reactions of the latter with amines, such as p-toluidine, cyclohexylamine, and piperidine, lead to the corresponding carboxamides.

We describe the effect of the solvent during the intra-cyclization of the arylhydrazonomalononitrile to obtain new and useful substituted cinnolines, namely 4-amino-3-cyanocinnolines and (4-amino-cinnolin-3-yl)arylmethanones. 4-Amino-3-cyano-5,7-dimethyl-cinnoline was treated with n-hexylamine, cyclohexylamine, and isopropylamine to yield the corresponding cinnoline-3-carboxamidine derivatives. Furthermore, 4-amino-3-cyano-5,7-dimethylcinnoline was reacted with diaminoethane to give 4-amino-5,7-dimethyl-3-(4,5-dihydroimidazol-2-yl)cinnoline. Treatment of 4-amino-3-cyano-5,7-dimethylcinnoline with hydrazine hydrate provided 3-amino-7,9-dimethyl-1H-pyrazolo[4,3-c]cinnoline. Moreover, (4-aminocinnolin-3-yl)phenylmethanones were treated with hydrazine hydrate to give 3-phenyl-1H-pyrazolo[4,3-c]cinnolines. Finally, reactions of (4-aminocinnolin-3-yl)phenylmethanone with 3,5-dimethylaniline, phenyl hydrazine, hydroxylamine, and phenyl isothiocyanate are discussed. Chemical and spectroscopic evidence for the structures of the new compounds is presented.

The influence of temperature on the rate constants of photoinduced intermolecular electron transfer, representing the first stage of photoinduced reactions, has been investigated based on analysis of the quenching of fluorescence of carbazole vapor by halomethanes (CHCl3, CH2Br2, CCl4, CHBr3) and delayed fluorescence of benzophenone and anthraquinone vapors by aliphatic amines (diethylamine, dibutylamine, cyclohexylamine, triethylamine) and pyridine. It has been established that the rate constants of photoinduced electron transfer in different donor-acceptor pairs in the gas phase can increase or decrease with increase in the temperature from 433 to 623 K. The energies of activation and enthalpy of the fluorescence-quenching process have been determined. The interrelation between the rate constants of fluorescence quenching kq and the free energy of electron transfer ΔGET has been analyzed with account for the mean vibrational energy of the interacting molecules. It is shown that positive and negative temperature dependences kq(T) are characteristic, respectively, of the regions of normal (kET increases with decrease in ΔGET) and inverted (kET decreases with decrease in ΔGET) changes in the rate constants caused by an increase in the exothermicity of the photoinduced electron transfer process.

The effect of an N-M-1 inhibitor (a salt of cyclohexylamine and C10 to C16 aliphatic acids) on the corrosion of sintered powder steels ЖГр1Д3 and ЖГр1Н4М1 (with the 14 to 17% porosity) in distilled or tap water at 20 to 80°C, as well as in 0.05 M Na2SO4 solution, is studied by gravimetric and electrochemical methods. The protective concentration of the inhibitor is lower in distilled, than in tap water or sodium sulfate solution. The protective action decreased with an increase in temperature. In tap water or sodium sulfate solution, the corrosion-inhibiting effect is weaker for ЖГр1Д3 than for ЖГр1Н4М1.

Kinetics and equilibria of axial ligation of bromomethyl(aquo) cobaloxime by a series of straight chain primary amines (methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine), cycloamines (cyclopentylamine, cyclohexylamine, cycloheptylamine) and secondary amines (N,N-dimethylamine, N,N-diethylamine) have been measured as functions of pH by spectrophotometric technique in aqueous solution, ionic strength 1 M (KCl) at 25°C. The rate of substitution of H2O varies with the pKa of incoming ligand, thus establishing nucleophilic participation of the ligand in the transition state. Binding and kinetic data are interpreted based on the basicity and steric influence of the entering ligand. To compare the rate constants of the entering ligands, pH independent second-order rate constants (k on ) are calculated.

Effects of impeller characteristics have been studied in the hydrogenation of aniline on Ru/C catalyst. Dual impellers were employed and the experiments were performed at 300 rpm using a lab-scale reactor. Reaction with disk turbines (DT) resulted in the higher cyclohexylamine (CHA) selectivity and higher reaction rate compared to that with pitched blade turbines (PBT). When a combination of PBT and DT impellers was employed, high product selectivity and reaction rate were obtained and the selectivity was maintained constant. Changes in the product selectivity with the impeller geometry were explained in terms of the relative rates of the side reactions depending on the hydrogen concentration in the reaction mixture.

Thermosetting resins of interpenetrating network structure (IPN) are gaining in importance owing to their outstanding toughness characteristics. The combination of styrene crosslinkable vinylester (VE) and amine crosslinkable epoxy (EP) resins is very promising as their mechanical and rheological properties can be tailored in a broad range [1–4]. It was recently argued that VE with an aromatic backbone (bisGMA type) should be combined with EPs of aliphatic or cycloaliphatic build-up in order to achieve optimum toughness [4, 5]. The presence of IPN in the related VE/EP hybrids was demonstrated using “physically etched” specimens produced by ion bombardment [6]. Note that various ablation procedures (including laser treatment [7, 8]) proved to be suitable tools to study the morphology of thermosetting resins. Interestingly, only few works were dedicated to the fatigue crack propagation (FCP) of interpenetrated thermosets [9, 10] although this behavior is of paramount importance for many engineering applications. Therefore the present investigation was focused to study the FCP behavior of VE/EP combinations as a function of VE/EP ratio, EP formulation and curing conditions. The commercial VE resin (bisphenol-A based bismethacryloxy type, bisGMA) was a product of DSM Composite Resins (Daron©R XP-45-A-2; styrene content: 30 wt%, ratio of the double bonds VE/styrene= 1:1.2). For its curing 0.75 phr (parts per hundred resin) dibenzoylperoxide and 0.15 phr N,N-diethylaniline accelerator were used. The EP resins selected for this study were of aliphatic (Al) and cycloaliphatic (Cal) nature. As aliphatic (Al-EP) 1,4-butanediyldiglycidylether and as cycloaliphatic EP (Cal-EP) 1,4cyclohexanedimethanoldiglycidylether (Polypox R3 and R11, respectively, from U. Prumer PolymerChemie) served. Al-EP was cured by a cycloaliphatic diamine (Cal-Am) procured from Vantico Ltd. (HY2954 grade: 2,2′-dimethyl-4,4′-methylenebis(cyclohexylamine)), whereas Cal-EP with an aliphatic diamine (Al-Am) purchased from Aldrich (1,2-bis(2-aminoethoxy)ethane). The cure regime of the plaques produced in an open PTFE-mold was as follows: room temperature for 12 h, 80 ◦C for 3 h and

The host complex Cd(Cyclohexylamine)2Pd(CN)4 has been prepared in powder form. The spectral data suggest that the structure of this complex issimilar to those of the Hofmann-dma-type hosts. The sorption processes of thearomatic guests (benzene, toluene,o-, m-, p-xylene, naphthalene, 1,2-, 1,3-, 1,4-dichlorobenzene and 1,4-dibromobenzene) in this host have been examined at room temperature by gravimetric and spectroscopic measurements.The desorption of the benzene guest against time has been measured. The hoststructure changes on inclusion of the guests and recovers after liberations. Thehost complex has been suggested as sorbents for selective absorption.

The imprinted polymers based on a transient complex formation between methacrylic acid and template molecules were prepared by using methacrylic acid and ethylene dimethacrylate as a cross-linking agent. The template molecules used were (R,R)-cyclohexanediamine (1), (S,S)-1,2-diphenylethylenediamine (2) and (S)-1,1'-binaphthyl-2,2'-diamine (3). Another group of templates were those in which the amino group of these templates had been substituted by the hydroxy group: (R,R)-1,2-cyclohexanediol (4) and (S,S)-hydrobenzoin (5). Racemic 2 was separated by the polymer prepared with template 2 (P2) and that with template 1 (P1). Template 2 is larger than template 1 in steric bulkiness, but P1 was effective for the enantiomer separation of racemic 2. P1 was not effective for the separation of racemic 4. Enantioselectivity observed in racemic 2 in P2 was higher than that in racemic 1 in P1. P2 has no definite predetermined shape for solute 1, but it was capable of separating racemic 1. This separation should be thus ascribed to the orientation of at least two carbonyl groups reflecting the conformation of template 2 in P2 cavity. Racemic 5, having the same configuration of the two bulky phenyl groups as that of solute 2, was separated in P2. When the primary amines such as propylamine, cyclohexylamine and 1-adamantanamine were added into the acetic acid-methanol mixtures as eluents, both enantioselectivity and retentivity for racemic 2 were enhanced along with the remarkable peak tailing.

Hydrolysates from chromed leather waste obtained in powdered form on an industrial scale by using biotechnical methods were analysed by TG an DSC techniques. Besides about 9% (mass/mass) of moisture, around 1% (mass/mass) of cyclohexylamine was found in the pulverized hydrolysates. Calorimetric measurement of the reaction heats of the reactions of the hydrolysates with commercially available aldehydes indicates that their reactivity decreases in the sequenceglutardialdehyde>>methylglyoxal≈acetaldehyde>>glyoxal>formaldehyde.

Polybromobenzenes C6Br5X (X = Br, F, CN, NO2) react with primary amines (methylamine and cyclohexylamine) to give nucleophilic substitution products; reactions of the same substrates with secondary amines (dimethylamine, diethylamine, piperidine, and morpholine) are accompanied by hydrodebromination processes.

The integrated immersion heats of naturally oxidized powdered iron in water and organic liquids (n-octylamine, n-octanol, and n-undecane) and the adsorption heats of the vapors of water, octylamine, cyclohexylamine, and a mixture of primary aliphatic amines with C9–C13 alkyl radicals were measured by calorimetry. The interaction energy of powdered iron with octylamine was found to be higher than with normal hydrocarbons (C10) or alcohols (C8) and at least two times that with water, because a specific (donor-acceptor) interaction of an adsorbent with amino group is stronger than with OH group of water and alcohols. The surface properties of powdered iron were compared with those of hydroxylated silica gel and carbon.