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Organic–inorganic metal halides (OIMHs) possess low preparation costs and high photoluminescence quantum yield. Within a specific range, the temperature‐dependent nature of OIMHs' luminescent lifetime facilitates temperature sensing and thermal imaging functionalities. In this study, a non‐toxic (C10H22N)6SbBr9·H2O ([C10H22N]+ is 4‐(tert‐buty)cyclohexanamine cation) with a 0D structure crystallized in the Pbcn space group is obtained. Under blue light excitation at room temperature, it demonstrates intense broad emission centered at 635 nm. Further investigation into the correlation between temperature and photoluminescence lifetime has unveiled exceptional temperature sensing precision. The relative sensitivities within the range of power system temperature alert 30–70 °C lie between 2.5% and 4.5% K−1. This matches the typical high‐temperature warning threshold for power systems. Moreover, after immersion in water and alcohol, the compound maintains remarkable stability, with multiple heating/cooling cycles confirming its reliability under test temperatures. Additionally, a composite thin‐film device composed of (C10H22N)6SbBr9·H2O, showcasing its potential as a stable and durable thermal imaging temperature sensing device is fabricated. [ABSTRACT FROM AUTHOR]

Two epimeric pairs of N‐Ts‐protected cyclohexylamines that incorporate an unsaturated side‐chain at the C2 position have been prepared. Contrary to expectations, none of these underwent clean, photochemically‐induced intramolecular hydroamination reactions to give the corresponding perhydro‐indole or ‐quinoline. However, they did participate in efficient olefin cross metathesis (OCM) reactions with methyl crotonate. Three of the four acrylates so‐formed engaged in base‐promoted and completely diastereoselective, intramolecular aza‐Michael addition (cyclization) reactions to give the isomeric and C2‐substituted perhydro‐indoles or ‐quinolines with the structures of these being confirmed by single‐crystal X‐ray analyses. DFT calculations generated results consistent with the observed diastereoselectivities and the proposed transition states. Manipulation of the ester groups associated with the cyclization products allowed for their conversion, inter alia, into the corresponding n‐propyl residues and thus providing novel analogues of neurotoxic alkaloids such as pumiliotoxin C. [ABSTRACT FROM AUTHOR]

Commercial NH4-Beta and Na-ZSM-5 zeolites were fluorinated with different amounts of NH4F and using different procedures (room temperature, conventional refluxing, microwave refluxing). Samples were characterized by XRD, N2 physisorption, FTIR, 1H NMR, SEM-EDS, and TGA of adsorbed cyclohexylamine. An increase in the concentration of NH4F led to fluorinated zeolites with higher surface areas and slightly lower amounts of Brønsted acid sites due to some dealumination. Fluorination by conventional or microwave refluxing at shorter times did not dealuminate ZSM-5, resulting in the formation of higher particle sizes. Ni/fluorinated beta catalysts were more active than Ni/fluorinated ZSM-5 catalysts for the hydrodeoxygenation of guaiacol at 180 °C and 15 bar of H2 for 1 h due to their higher amount of acid sites. The appropriate proportion of metallic and Brønsted acid centers allowed for the selective obtention of cyclohexane (58%) for the Ni supported on beta fluorinated with NH4F 0.1 M catalyst. The combination of this fluorinated beta to a Ni/ordered mesoporous carbon catalyst significantly boosted its selectivity to cyclohexane from 0 to 65%. Fluorinated ZSM-5 samples, although having stronger Brønsted acid sites, as observed by 1H NMR, they had lower amounts, leading to higher selectivity to cyclohexanol when used as catalytic supports. [ABSTRACT FROM AUTHOR]

The oil used to fry food is often used multiple times to reduce costs. However, when foods containing sweeteners are processed in this way, the sweeteners may produce substances harmful to the body as a result of repeated frying at high temperatures. This article investigated the stability of sodium cyclamate during deep-frying by HPLC using a pre-column derivatization method. The results showed that cyclohexylamine was a decomposition product of a standard sample of sodium cyclamate when deep-fried at 200°C for 25 min. A pre-column derivatization/HPLC method was established to determine cyclohexylamine, a decomposition product of sodium cyclamate, under these conditions. Dansyl chloride was used as the derivatization reagent, the derivatization temperature was 60°C, the derivatization time was 20 min, the pH of sodium bicarbonate buffer solution was 11, and the concentration of dansyl chloride was 2.0 mg/mL. Detection was carried out by using an Agilent 1260 high-performance liquid chromatograph coupled with an ultraviolet detector. The ultraviolet detection wavelength was 254 nm, and the mobile phase was acetonitrile-1.0 g/L potassium dihydrogen phosphate solution at a flow rate of 1.0 mL/min. Gradient elution was adopted, the peak of the cyclohexylamine derivative appeared at a retention time of 17.75 min, and the peak area response value was the largest. The methodological validation analysis showed that the detection limit of cyclohexylamine was 0.5 mg/kg, the quantification limit was 2.0 mg/kg, and the spiked recoveries were in the range of 99.37–110.16%. The relative standard deviations (RSDs) were in the range of 0.17–1.26%. Four samples were tested and analyzed by the established method, and cyclohexylamine was not detected. [ABSTRACT FROM AUTHOR]

Molecular weight distribution (MWD) is a key characterization parameter of polymers and has crucial impact on the properties of polymers. The MWD regulation of polypeptoids, an attractive class of biomaterials, has not been reported so far. This study designed and synthesized the photolabile dormant initiator, 2-nitro-4,5-dimethoxybenzylcyclohexylaminecarbamate, for the ring-opening polymerization of N-butyl-N-carboxyanhydride (BuN-NCA). Upon the ultraviolet (UV) light irradiation (360 nm), the photolabile dormant initiator could release the active cyclohexylamine. The release amount was well controlled by manipulating the duration of the applied radiation. The release amount of cyclohexylamine was increased as the time of UV irradiation increased from 1 h to 4 h, resulting in the Mn decrease of the polypeptoid (from 9.6×10³ to 4.6×10³). The release rate of cyclohexylamine was controlled by the intervals of the applied UV irradiation. The early released cyclohexylamine initiated the monomer to form longer chains while the lately released cyclohexylamine initiated the monomer to form shorter chains. Thus, the MWDs of polypeptoids were well regulated in situ. This study provides the possibility to tune the Mn and MWD of polypeptoids in a more precise manner, and also lays the foundation for the investigation of the relationship between the MWD and the properties of polypeptoids. [ABSTRACT FROM AUTHOR]

The density, viscosity and sound velocity of the binary liquid mixtures of P-methyl acetophenone with cyclohexylamine, cyclohexanol, and cyclohexane are measured over the complete composition range at temperatures of 303.15–313.15 K and at atmospheric pressure of 0.1 M. Excess molar volume, excess isentropic compressibility and viscosity deviation are calculated from the experimental measurements. The sign and magnitude of the derived parameters reveal the nature and type of interactions between the constituent molecules in the binary mixtures. Thermodynamic properties for this work reveal association interactions between dissimilar molecules in the binary systems P-methyl acetophenone + cyclohexylamine and P-methyl acetophenone + cyclohexanol systems, whereas dispersion forces cause the opposite trend in the other binary system P-methyl acetophenone + cyclohexane. [ABSTRACT FROM AUTHOR]

This study examined the kinetic reaction between hydrogenated dimer fatty acid C36 and 4,4′-methylene bis(cyclohexylamine) in the melt phase at 140, 145, 150, 160, and 165 ºC. The acid value, degree of polymerization, number average molecular weight, and weight average molecular weight were calculated at different times. Infrared spectroscopy was used to determine the structure of the resulting polymer. The kinetic degradation was carried out using thermogravimetric analysis, and thermodynamic and equilibrium constants were defined. Additionally, differential scanning calorimetric was used to determine the thermodynamic constants for melting. The kinetic of the polyamidation reaction was discovered to be of overall second order, with an activation energy of 187.45 kJ/g mol up to 80, 84, 92, 93, and 94% conversion at 140, 145, 150, 160, and 165 ºC, respectively. After reaching these conversion percentages, the reaction becomes overall third order. [ABSTRACT FROM AUTHOR]

In order to achieve effective removal of radioactive iodine, trace detection of dinitrophenol (DNP), here, we have synthesized two porous organic polymers (POPs, TMCHA and HMCHA) by nucleophilic substitution reactions with specific surface areas of 1730 and 1796 m2 g−1, respectively. The adsorption capacities of POPs in iodine vapor and cyclohexane and the fluorescence sensing performances for DNP are studied. The results show that the adsorption capacities of TMCHA and HMCHA in iodine vapor are as high as 3.77 and 2.74 g g−1, and the removal efficiencies of iodine in iodine-cyclohexane solution are 97% and 73%, respectively. The iodine adsorption mechanism of the MCHA-based POPs is the electron transfer mechanism. The Stern–Volmer quenching constants (Ksv) of TMCHA and HMCHA for fluorescence quenching of DNP are 4.04 × 103 and 4.42 × 103 L mol−1, respectively. The fluorescence quenching of TMCHA and HMCHA was caused by FRET and PET together. [ABSTRACT FROM AUTHOR]

In this work, we investigated the reaction of cyclamate with hypochlorous acid (HOCl) in simulated gastric juice. The reaction products were detected by high-performance liquid chromatography diode array detection (HPLC-DAD) and ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). We also explored the changes in product concentration as a function of reaction time, cyclamate and HOCl concentrations. Cyclamate reacted with hypochlorous acid instantly in the simulated gastric fluid. N, N-dichlorcyclohexylamine and cyclohexylamine were both detected when the HOCl concentration was at millimole. Cyclohexylamine can only be found when HOCl concentration was at micromole. N, N-dichlorcyclohexylamine and cyclohexylamine concentrations both increased when cyclamate concentration increased under the millimole level of HOCl. As an important reactive oxygen species, hypochlorous acid (HClO) is produced in various physiological processes. The abnormal rise of the HClO level is associated with many inflammatory diseases. Chronic gastritis associated with Helicobacter pylori is a multistep, progressive, life-long inflammation. So, chronic gastritis infected with H. pylori may cause cyclamate metabolizing into cyclohexylamine in vivo. [ABSTRACT FROM AUTHOR]

Organic ferroelectrics have received a great deal of interest due to their exclusive properties. However, organic ferroelectrics have not been fully explored, which hinders their practical application. Here, we presented a novel metal‐free organic molecular ferroelectric [4‐MCHA][ClO4] (1) (4‐MCHA=trans‐4‐methylcyclohexylamine), which exhibits an above‐room‐temperature of 328 K. Strikingly, the single crystal structure analysis of 1 shows that the driving force of phase transition is related to the interesting chair‐boat conformation change of 4‐MCHA cation, in addition to the order‐disorder transition of ClO4− anion. Using piezoelectric response force microscopy (PFM), the presence of domains and the implemented polarization switching were clearly observed, which explicitly determined the presence of room‐temperature ferroelectricity of 1. As far as we know, the ferroelectric phase transition mechanism attributed to the conformational change in a trans isomeric cation is very rare. This research enriched the path of designing ferroelectric materials and smart materials. [ABSTRACT FROM AUTHOR]

A series of metal (II) complexes of N‐cyclohexyl amine dithiocarbamate ligand are synthesized and characterized by Fourier transform infrared, 1H, 13C NMR, mass spectroscopy, and elemental analysis. The surface structural pattern of the prepared complexes were investigated by scanning electron microscope and X‐ray diffraction techniques. The prepared complexes possessed crystalline characteristic with size average ranging from 16 to 30 nm. Moreover, the biological activity of the synthesized complexes were tested against Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. Among the prepared complexes, copper (II) complex displayed the highest activity. In addition, molecular docking study was performed against bacterial tyrosinase enzyme which showed good binding interactions and is in agreement with the experimental findings. Furthermore, the in silico toxicity studies reveal that the complexes are mostly non‐irritant with mild toxicity. Different quantum parameters including electron affinity, ionization energy, dipole moment, hardness and vibrational frequencies were calculated for the ligand and its complexes using Gaussian 09 program and B3LYP/SDD level of theory. [ABSTRACT FROM AUTHOR]

In this study, a series of Co-based catalysts with alkali metal carbonate promoters were prepared to investigate the interrelation between promotion effect of these carbonates and catalytic performance for aniline hydrogenation to cyclohexylamine in vapour phase. The chemical promoters Li2CO3 and Na2CO3 leading to decrease in catalytic activity of cobalt catalysts for aniline hydrogenation. Catalysts with K2CO3 and Cs2CO3 loadings have practically no catalytic activity for hydrogenation of aniline. Results of TPD of aniline proved that presence of alkali metals carbonates restricts the adsorption of aniline on the surface of cobalt catalysts. Further, it was found that the addition of Na2CO3 greatly enhances the catalytic selectivity towards the cyclohexylamine and inhibits the consecutive reactions of cyclohexylamine leading to formation of by-products such as dicyclohexylamine and N-phenylcyclohexylamine.

Phenol amination to various valuable amines has attracted considerable attention in heterogeneous catalysis, but limited studies have focused on non‐noble metal catalysts. This study reports a bifunctional catalyst (Ni/SiO2‐AE) containing nickel nanoparticles and Lewis acid sites derived from nickel phyllosilicates for efficient amination of phenol to cyclohexylamine. The Ni/SiO2‐AE catalyst resulted in 89.4% phenol conversion and 86.0% selectivity to cyclohexylamine at 160 °C for 2 h, which outperforms the catalysts by conventional deposition‐precipitation (Ni/SiO2‐DP) and wetness‐impregnation (Ni/SiO2‐WI). The turnover frequencies based on the actual exposed metal surface area for Ni/SiO2‐AE, Ni/SiO2‐DP, and Ni/SiO2‐WI are calculated as 71.7, 49.0, and 8.7 h−1, respectively. Results demonstrate that the Ni nanoparticles exsoluted from nickel phyllosilicates participate in the activation of dihydrogen molecules, and the Lewis acid sites stemmed from coordination unsaturated Ni2+ sites on the catalyst serve to adsorb and activate phenol. The synergistic effect of the dual‐functions intensifies the phenol amination. [ABSTRACT FROM AUTHOR]

A new substance was obtained from the class of coordination compounds based on a modified thiosemicarbazone, namely from the class of hydrazonomethanesulfinates that can be used both in the fields of chemistry and medicine. The iron ion is the central atom that forms the complex compound in question, having the +3 oxidation state and an octahedral surround with the new ligand obtained following the directed redox reaction. The antimicrobial activity of the coordination compound on Bacillus cereus is hundreds of times higher than that of reference substances such as nitrofural. [ABSTRACT FROM AUTHOR]

A benign approach is proposed for the highly efficient synthesis of cyclohexanone oxime through nonsolvent liquid‐phase oxidation of cyclohexylamine with dioxygen over supported TiO2/silica gel. The as‐prepared catalyst was characterized by Brunauer–Emmett–Teller (BET), Fourier‐transform infrared spectroscopy (FT‐IR), scanning electron microscope (SEM), X‐ray photoelectron spectroscopy (XPS), and X‐ray powder diffraction (XRD) analyses. The results indicate that titanium active sites could be grafted on silica gel supports as catalytic centres. Various parameters such as reaction time and reaction temperature were systematically optimized; the results showed that supported 20%TiO2/silica gel exhibited the best catalytic effect with 63.2% of amine conversion and 86.3% of selectivity to CHO. A possible pathway is proposed for cyclohexylamine oxidation over supported TiO2/silica gel. The method developed in this study using dioxygen as the oxidant and inexpensive TiO2/silica gel as an efficient catalyst has incredible industrial application potential for green synthesis of cyclohexanone oxime. [ABSTRACT FROM AUTHOR]

Nonradiative recombination at perovskite/charge transport layer interfaces is caused by surface defects and instability, and it is known to limit the long-term development of perovskite solar cells (PSCs). To overcome this issue, the three-dimensional/two-dimensional (3D/2D) perovskite heterojunction has emerged as a possible solution to improve the stabilities and efficiency of PSCs. Herein, we employ a simple one-step method to prepare n-i-p-structured PSCs using a 3D/2D perovskite heterojunction as the absorption layer. For this purpose, the large and non-centrosymmetric 4,4-difluorocyclohexylammonium (DFCHA+) cation, which has been confirmed to be a valid organic spacer in 2D Ruddlesden–Popper (RP) phase perovskites, is employed as an organic ligand for post-treatment of the surfaces of MAPbI3 films. The presence of an ultrathin 2D RP phase perovskite was confirmed on the surface, and the 3D/2D perovskite heterojunction was successfully constructed. Benefitting from surface post-treatment, the density of the surface trap states was reduced with effective passivation. In addition, nonradiative recombination was suppressed, and the interface bands were aligned. As a result, the optimal device achieved a power conversion efficiency of 21.93% with a remarkable open-circuit voltage (VOC) of 1.14 V, a current density (JSC) of 23.71 mA cm−2, and a fill factor of 0.82. Furthermore, owing to the hydrophobicity of the DFCHA+ cation, the unencapsulated device was able to maintain an initial efficiency of 82.3% after storage for 500 h at a relative humidity of ∼45%. We believe that this post-treatment strategy has wide application potential in the field of photovoltaic devices. [ABSTRACT FROM AUTHOR]

Antioxidants play a role in the transformation of free radicals into more stable chemical structures. Work on phenolic antioxidants has accelerated in recent years. Curcumin is a natural phenolic with antioxidant properties. In this study, a salt-supported homogenous liquid-phase microextraction method was used for preconcentration and spectrophotometric determination of curcumin for the first time. The curcumin was transferred into the organic phase using cyclohexylamine as the extraction solvent at pH values between 2.0 and 7.0 and determined by spectrophotometry. The results showed that the performance of the method for curcumin was unaffected by pH. The pH of the sample solution, the mass of salt, and the volume of the solvent were optimized, and the influence of the matrix types was investigated. The limits of detection and quantification were 1.44 and 4.80 µg L−1 for curcumin. The developed method was employed for the analysis of food samples. [ABSTRACT FROM AUTHOR]

Treatment of the double nuclear complex 1a, di-μ-cloro-bis[N-(4-formylbenzylidene)cyclohexylaminato-C6, N]dipalladium, with Ph2PCH2CH2)2PPh (triphos) and NH4PF6 gave the single nuclear species 2a, 1-N-(cyclohexylamine)-4-N-(formyl)palladium(triphos)(hexafluorophasphate). Reaction of 2a with Ph2PCH2CH2NH2 in refluxing chloroform via a condensation reaction of the amine and formyl groups to produce the C=N double bond, gave 3a, 1-N-(cyclohexylamine)-4- N-(diphenylphosphinoethylamine)palladium(triphos)(hexafluorophasphate); a potentially bidentate [N,P] metaloligand. However, attempts to coordinate a second metal by treatment of 3a with [PdCl2(PhCN)2] were to no avail. Notwithstanding, complexes 2a and 3a left to stand in solution spontaneously self-transformed to give in either case the double nuclear complex 10, 1,4-N,N-terephthalylidene(cyclohexilamine)-3,6-[bispalladium(triphos)]di(hexafluorophosphate), after undergoing further metalation of the phenyl ring, then bearing two mutually trans [Pd(Ph2PCH2CH2)2PPh)-P,P,P] moieties: an unprecedented and serendipitous result indeed. On the other hand, reaction of the double nuclear complex 1b, di-μ-cloro-bis[N-(3-formylbenzylidene)cyclohexylaminato-C6, N]dipalladium, with Ph2PCH2CH2)2PPh (triphos) and NH4PF6 gave the single nuclear species 2b, 1-N-(cyclohexylamine)-4-N-(formyl)palladium(triphos)(hexafluorophasphate), Treatment of 2b with H2O/glacial MeCOOH gave cleavage of the C=N double bond and of the Pd···N interaction, yielding 5b, isophthalaldehyde-6-palladium(triphos)hexafluorophosphate, which then reacted with Ph2P(CH2)3NH2 to yield complex 6b, N,N-(isophthalylidene(diphenylphosphinopropylamine)-6-(palladiumtriphos)di(hexafluorophosphate), with two pairs of non-coordinated nitrogen and phosphorus donor atoms. Treatment of 6b with [PdCl2(PhCN)2], [PtCl2(PhCN)2], or [PtMe2(COD)] gave the new double nuclear complexes 7b, 8b and 9b, palladiumdichloro-, platinumdichloro- and platinumdimethyl[N,N-(isophthalylidene(diphenylphosphinopropylamine)-6-(palladiumtriphos)(hexafluorophosphate)-P,P], respectively, showing the behavior of 6b as a palladated bidentate [P,P] metaloligand. The complexes were fully characterized by microanalysis, IR, 1H, and 31P NMR spectroscopies, as appropriate. The X-ray single-crystal analyses for compounds 10 and 5b have been previously described as the perchlorate salts by JM Vila et al. [ABSTRACT FROM AUTHOR]

The preparation and characterization of a new chiral tertiary dibenzylamine are described. These molecules are well known in the literature for their high neuropharmacological potential. The general synthetic pathway is based on asymmetric Aza–Michael addition of chiral (R)-N-benzyl-N-(α-methylbenzyl)amide to methyl cyclohex-1-en-carboxilate obtaining the β-amino ester, followed by carboxylic acid hydrolysis and subsequent Barton descarboxylation. Interestingly, it is a general synthetic procedure of a wide range of chiral amines by careful choice of insaturated esters and alkylation of the chiral enolate in the initial reaction. The new tertiary dibenzylamine molecule is fully characterized by NMR Spectroscopy (1H and 13C), as well by High-Resolution Mass Spectrometry and Infrared Spectroscopy. [ABSTRACT FROM AUTHOR]

We scrutinise the adsorption of cyclohexylamine (CHA) on pure and Cu-doped BN-nanotube (Cu@BN-NT) through density functional theory calculations. CHA had a weak interaction with the pristine BN-NT, making BN-NT not suitable to be used as a sensor. However, there was a substantial rise in the reactivity and sensitivity of the BN-NT after replacing the B with metal Cu, based on the standard Gibbs free energy of formation. There is a reduction in the energy gap of the HOMO–LUMO of Cu@BN-NT from 2.28 to 1.42 eV (∼ −37.7%) when CHA was adsorbed, which substantially increased the electrical conductivity. Hence, converting the substantial change in the electrical conductivity into an electronic signal was possible, which demonstrated that the Cu@BN-NT was an encouraging sensor to detect CHA. The computed recovery time for the Cu@BN-NT was 26.8 s, which is short. [ABSTRACT FROM AUTHOR]

• An ionic complex (MV) [Eu(NTA) 4)] 2 (1) has been synthesized and characterized. • Paper-based fluorescence sensor was prepared based on this complex probe (1). • The sensor exhibits rapid quenching sensing behavior of PL emission. • The T 90 value of detection for cyclohexylamine sensing is as low as 30 s. • The limit of detection for cyclohexylamine sensing is as low as 3 ppm. A new fluorescent amine probe of ionic complex (MV) [Eu(NTA) 4)] 2 (1) (MV = Methyl viologen, NTA = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione) has been designed and synthesized. Single-crystal X-ray diffraction shows that 1 crystallizes with four independent mononuclear cationic complexes, solvated by two hexane, one dichloromethane, one alcohol and three water molecules counterbalanced by two MV2+ cations (1 •hexane•0.5DCM•0.5EtOH•1·5H 2 O). Both in solid state and in doped films, this probe material exhibits strong red fluorescence emission dominated by 5D 0 →7F 2 transition of Eu3+ ions. On the basis of this complex fluorescence probe, a paper-based thin film fluorescence sensor with fast and sensitive sensing performance to cyclohexylamine (CYA) was developed by PMMA composite preparation process. When the paper based sensor is placed in an atmosphere containing CYA vapor, its photoluminescence (PL) intensity decreases rapidly, showing a typical fast quenching fluorescence sensor. [Display omitted] [ABSTRACT FROM AUTHOR]

Cyclohexylamine was found to be an efficient organocatalyst for the synthesis of structurally diverse 2-amino- 4H-chromenes by multicomponent reaction of (substituted) salicylaldehydes, active methylene compounds and nitroalkanes at ambient temperature and under solvent-free conditions. The synthesis of a variety of 2- amino-4H-chromenes was achieved using the reaction of (substituted) salicylaldehydes with two different C-H acids. The present protocol, which employed commercially available cyclohexylamine as an organocatalyst, offered the advantages of operational simplicity and avoidance of conventional purification methods and the obtained products were essentially pure. [ABSTRACT FROM AUTHOR]

L-aspartic acid is a natural amino acid and a building block for peptides and proteins. Besides, a series of compounds and metallic complexes such as metalloproteins which contain acid residues have biological applications. In this course, a new route of preparation of β-L-aspartyl-cyclohexylamide was carried out by regioselective acylation of cyclohexylamine using N-phthaloylL-aspartic anhydride, followed by hydrolysis of phthaloyl group with hydrazine hydrate. The preparation of β-L-aspartylamide was attempted by an original method which involved 4 steps of synthesis. In the first synthetic step, N-carbethoxyphthalimide was used through a method developed in our group, managing to improve the conditions of reaction to not affect the chiral center. The second activation phase was performed in good yields, obtaining the pure product. In the third stage, the amine regioselectively attacked the β position and in the last step, the amide deprotection was achieved by hydrazinolysis. The structure of the intermediates and the final amide product was confirmed by HRMS, ¹H- and 13C-NMR. [ABSTRACT FROM AUTHOR]

The forward osmosis (FO) membrane exhibits great performance degradation when contacting with chlorine solutions. The damage of chlorine to membrane material will seriously reduce the lifetime of the membrane and increase the cost of membrane treatment technology. Here, we prepared chlorine-stable membranes by a covalent modification method with cyclohexylamine. The cyclohexylamine observably changed the surface morphology, the roughness (arithmetic average) of the membrane decreased from 22 to 17.2 nm. The addition of cyclohexylamine produced a denser sacrificial layer of short chain polyamide, which made modified membranes possess significantly better chlorine resistance with slightly declined water flux. The water flux of the optimal modified membrane was 10.78 Lm−2 h−1, only 13% less than that of the pristine membrane. Importantly, after 20,000 ppm·h chlorine exposure, the membrane with 1.5 wt% cyclohexylamine had a salt rejection of 77.2% and showed 26.0% lower water flux than pristine TFC (thin film composite) membrane in FO mode. Notably, the grafting membranes could maintain a high performance under acidic chlorination conditions. The membrane with best performance had a salt rejection of 81.6%, exhibiting 24.4% higher salt rejection than pristine membrane with 20,000 ppm·h chlorine exposure at a pH of 4. The cyclohexylamine endowed the FO membrane with better chlorine resistance, making it attractive for the development of chlorine-resistant membrane for environmental and desalination processes. HIGHLIGHTS The addition of cyclohexylamine produced a chlorine-resistant sacrificial layer.; The 1.0 wt% addition of cyclohexylamine did not significantly decrease the water flux of the forward osmosis membrane.; Under acidic conditions, cyclohexylamine could still significantly improve the chlorine resistance of forward osmosis membranes.;

Cyclic primary amines are elementary building blocks to many fine chemicals, pharmaceuticals, and polymers. Here, a powerful one‐pot Raney Ni‐based catalytic strategy was developed to transform guaiacol into cyclohexylamine using NH3 (7 bar) and H2 (10 bar) in up to 94 % yield. The methodology was extendable to the conversion of a wider range of guaiacols and syringols into their corresponding cyclohexylamines. Notably, a crude bio‐oil originating from the reductive catalytic fractionation of birch lignocellulose was transformed into a product mixture rich in 4‐propylcyclohexylamine, constituting an interesting case of catalytic funneling. The isolated yield of the desired 4‐propylcyclohexylamine reached as high as 7 wt % (on lignin basis). Preliminary mechanistic studies pointed at the consecutive occurrence of three key catalytic transformations, namely, demethoxylation, hydrogenation, and amination. [ABSTRACT FROM AUTHOR]

Nowadays, the vigorous development of biomass catalytic valorization is gradually moving towards a promising era. Integrating nitrogen elements into biomass catalytic systems promises more possibilities for upgrading the roadmap of biomass feedstocks. The amination of lignin to cyclohexylamine and its derivatives is a potential alternative to the fossil-based pathway. One-pot catalytic amination of lignin model compounds is challenging and inefficient due to their structural characteristics. Concerning the amination pathway, cyclohexanone and cyclohexanol are important intermediates. Based on this, we discuss the structural preferences of catalysts in the selective hydrogenation process, as well as the amination process of cyclohexanone and cyclohexanol to guide the design of catalysts for the one-pot amination of lignin. Then, the catalytic amination systems are deeply analyzed based on their catalytic conditions. Finally, according to the current development status of lignin amination, the challenges and prospects are proposed for a better lignin valorization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrophobic microenvironment boosts the activity of Ru NPs; • Activity of Ru is significantly promoted with the addition of H 2 O; • H 2 O decreased NB adsorption strength on Ru surface and accelerated H* transfer. It is difficult to balance the two separate and connected reaction steps in the sequential hydrogenation of nitrobenzene (NB) to cyclohexylamine (CHA) via only tuning the active sites. In this work, we optimize the activity of supported Ru NPs in the one-pot NB hydrogenation to CHA by tuning the surface hydrophobicity of the catalysts and by investigating the solvation effect. The Ru supported on hydrophobic mesoporous silicas is more active than that on hydrophilic mesoporous silicas, which may be attributed to the enrichment effect of the former one for hydrophobic NB. Furthermore, the activity of Ru is significantly promoted with the addition of H 2 O in the reaction system. Systematic studies suggest that the water promotion effect is mainly related with the decreased adsorption strength of NB on Ru surface and the water accelerated H* transfer during the NB hydrogenation process. Our primary results suggest that the modification of the surface properties of the catalysts and the deeper understanding of the solvation effect play an important role in one-pot cascade reactions. [ABSTRACT FROM AUTHOR]

An environmentally friendly microextraction method which includes determination of trace levels of rhodamine B in cosmetic and detergent samples by using UV–vis spectrophotometric determination after enrichment with has been established heat-induced homogeneous liquid–liquid microextraction method. As extraction solvent, cyclohexylamine has been used, and the rhodamine B concentration in extraction phase was determined at 550 nm by using UV–vis spectrophotometry. The major parameters influencing in the method including pH, volume of cyclohexylamine, amount of NaCl, sample volume have been assessed. The influences of the matrix components were also investigated. The limit of detection, the limit of quantitation and linear range were found as 0.014, 0.047 and 0.047–4.79 μg mL−1, respectively. The relative standard deviation was 1.03%. The extraction procedure was applied to determination of rhodamine B in the cosmetic and detergent samples. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenation of nitrocyclohexane proved to be an attractive alternative source of various chemical compounds: cyclohexanone oxime, cyclohexanone, cyclohexanol, cyclohexylamine and dicyclohexylamine. A growing interest in this reaction has been observed in the last few years. Herein, we present the catalytic performance of Cu/SiO2, Co/SiO2 and CuCo/SiO2 in gas and liquid flow nitrocyclohexane hydrogenation. The analysis of synthesized catalysts morphology (BET, TPR, XRD, TEM) in terms of their catalytic behavior allows us to draw general conclusions and determine the optimal conditions for the production of desired products. Application of the monometallic copper leads to the formation of cyclohexanone as the main product, but with low activity. On the other hand, Co/SiO2 shows high activity but gives cyclohexylamine. Bimetallic system CuCo(3:1)/SiO2 allows for the efficient production of 100% cyclohexanone at 5 bar and 75 °C. [ABSTRACT FROM AUTHOR]

This work deals with a study of the effect of temperature on the cyclohexylamine disproportionation to dicyclohexylamine, conjointly with the thermodynamic analysis of this process. The laboratory experiments were carried out in a glass tubular continuous-flow reactor in a gaseous phase at the reaction temperature 433–463 K over a nickel catalyst. The results show, that the temperature has a trifling effect on equilibrium conversion of cyclohexylamine. However, temperature affects the formation of hydrocarbons, benzene and cyclohexane, and dehydrogenation products of dicyclohexylamine, i.e. N-cyclohexylidenecyclohexanamine and N-phenylcyclohexylamine. The latter one is the dominant product of dicyclohexylamine dehydrogenation. The disproportionation of cyclohexylamine has slightly exothermic character. At the experimental reaction temperature range, the cyclohexylamine disproportionation is spontaneous reaction and other reactions of this process are non-spontaneous.

Alicyclic amines are widely used in several types of industries, and considerable attention has been devoted to possible environmental pollution by alicyclic amines in hypersaline industrial wastewater. In this study, a new hypersaline tolerant bacterial TYUT067 capable of growing in liquid basal salt medium with cyclohexylamine (CHAM) as the sole carbon source and energy source, was isolated from soil, and discovered with highly efficient CHAM degrading ability. The strain TYUT067 was identified as Paenarthrobacter sp. based on 16S rDNA gene sequence, and its degradation characteristic was examined. The results revealed that the isolated TYUT067 could grow well under pH range of 6.5–10.0, temperature from 20 °C to 30 °C. For degradation of 60 mM of cyclohexylamine, 100% degradation could be finished within 120 h. The TYUT067 could degrade 10 mM CHAM under hypersaline conditions (3–5% NaCl, w/v), revealed the hypersaline tolerance of TYUT067. Different type of amines was also tested with TYUT067, the degradations of >90% were achieved toward several alicyclic amines. The current results suggested that TYUT067 was a potential species could be efficiently used for the degradation of alicyclic amines and might be applicable to a hypersaline wastewater treatment system for the removal of alicyclic amines. HIGHLIGHTS A new cyclohexylamine degradation bacterial strain TYUT067 was isolated from soil environment.; The isolated TYUT067 is an alkali-tolerant strain and mesophilic microorganisms.; The isolated TYUT067 can degrade CHAM under hypersaline environment.; The isolated TYUT067 can degrade various alicyclic amines.;

The article discusses the synthesis and ring-closing reactions of aminocyclohexane derivatives with unsaturated side chains at C2. These derivatives have been found to undergo stereoselective intramolecular reactions, resulting in the formation of octahydroindoles or decahydroquinolines. By manipulating the ester side chains, researchers have been able to synthesize analogues of neurotoxic alkaloids found in frogs. The article provides more information on this research, conducted by X. Wu, M.G. Banwell, and their colleagues. [Extracted from the article]

An efficient method for the synthesis of 1-isopropyl-4-isothiocyanato-4-methylcyclohex-1-ene has been developed with p-menth-3-en-1-amine as raw material. Next, a number of p-menth-3-en-1-amine thiourea derivatives (4a–f) have been obtained from the reactions between 1-isopropyl-4-isothiocyanato-4-methylcyclohex-1-ene and cyclohexylamine or the reactions between p-menth-3-en-1-amine and different isothiocyanates. Then, the herbicidal activities of these compounds were evaluated. The result indicated that some of these newly synthesised compounds displayed remarkable herbicidal activities against annual ryegrass. In addition, the derivative containing cyclohexane ring (4a) displayed much higher herbicidal activity against annual ryegrass than the derivatives containing benzene ring. [ABSTRACT FROM AUTHOR]

A new organic synthetic anion exchange resin (LSC‐436) containing cyclohexylamine group was prepared for the sorption of rhenium. The traditional batch tests were applied to investigate the mechanism of sorption for rhenium on LSC‐436 with respect to contact time, initial rhenium concentration, the value of pH and the amount of resin. The experimental data obtained from batch tests were modeled using the Langmuir/Freundlich isotherms and pseudo‐first‐kinetic and pseudo‐second‐kinetic models to obtain key dynamic parameters for investigating the mechanism of sorption of rhenium. The LSC‐436 resin was characterized using scanning electron microscopy (SEM‐EDS), Fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) techniques to further study the sorption mechanism. [ABSTRACT FROM AUTHOR]

Cyclohexylamine oxidase CHAOCCH12‐C2 was previously discovered and utilized in the chemo‐enzymatic synthesis of (S)‐1‐(4‐methoxybenzyl)‐1,2,3,4,5,6,7,8‐octahydroisoquinoline ((S)‐1 a), the key precursor for the industrial production of antitussive dextromethorphan. Herein, structure‐guided semi‐rational engineering and random mutagenesis were applied to CHAOCCH12‐C2, resulting in an evolved variant WXF‐FM which possessed five point mutations: H68Q/E198G/L200V/I201L/V209S and displayed >15‐fold higher kcat and improved stereoselectivity towards (R)‐1 a relative to the WT enzyme. WXF‐FM‐catalyzed deracemization of 200 mM of rac‐1 a was achieved at gram‐scale under Turner's deracemization conditions, affording (S)‐1 a in 76 % isolated yield with 97 % ee, demonstrating the effectiveness and great potential of this enzyme in the practical, green synthesis of dextromethorphan. Two bulky analogues of (S)‐1 a were also afforded with much higher optical purities in WXF‐FM‐catalyzed reactions than those obtained in WT enzyme‐catalyzed reactions. Through conducting complete deconvoluting experiments, presence of strong cooperative effect was revealed, and the mutational effect of H68Q on (R)‐1 a was suggested to be possibly applicable to related cyclohexylamine oxidases. Molecular dynamics (MD) simulations indicated the enlargement of binding and entrance cavities, and the formation of a new hydrogen‐bonding between FAD and (R)‐1 a both likely contributed to the enhanced catalytic activity. [ABSTRACT FROM AUTHOR]

In the present work, studies were conducted towards the synthesis of 2-[trans-4-(4-chlorophenyl) cyclohexyl]-3-hydroxy-1,4-naphthoquinone 5 with systematic reaction and recrystallization condition optimization to isolate 5 in high yield with better purity. Synthesis of 5 was done by the hydrolysis of 2-[trans-4-(4-chlorophenyl) cyclohexyl]-3-chloro-1, 4-naphthoquinone 4, which was isolated by the decarboxylative condensation of trans-4-(4-chlorophenyl) cyclohexanecarboxylic acid 3 with naphthoquinone moiety. After the hydrolysis of 4, isolation of crude 5 was done by the use of acetic acid instead of dilute hydrochloric acid, product 5 was isolated in good purity with very less polar impurities. The study extends to provide the polymorphic form I of 5 by the use of solvent combination for the recrystallization, prior art reports the use of a large volume of solvent for the isolation of polymorphic form I of 5. The use of a large volume of solvent becomes a bottleneck for the commercial synthesis of 5. Our efforts towards optimization of hydrolysis reaction and recrystallization of 5 with the use of the small volume of solvent combination had made the process to be more costeffective and commercially viable for large-scale manufacturing. [ABSTRACT FROM AUTHOR]

Two bidentate PNP ligands N,N-bis(di-p-tolylphosphino)cyclohexylamine (Cy-pTolPNP) (1) and N,N-bis(di-p-tolylphosphino)cyclobutylamine (Cb-pTolPNP) (2) were synthesized and crystallized. Coordination to the fac-[MI(CO)3]+ core (M = Re, 99Tc) yielded fac-[Re(Cy-pTolPNP)(CO)3Br] (1A), fac-[99Tc(Cy-pTolPNP)(CO)3Cl] (1B), fac-[Re(Cb-pTolPNP)(CO)3Br] (2A) and fac-[99Tc(Cb-pTolPNP)(CO)3Cl] (2B) in relatively good yields (56 to 86%): The structures of 1, 2, 1A and 1B were studied by single crystal X-ray crystallography. Preliminary mitochondrial/antimicrobial evaluation of the free ligand (N,N-bis(di-p-tolylphosphino)-cyclohexylamine) (1) and its respective fac-[Re(CO)3]+ (1A) complex indicates that neither the free ligand nor the complex was active against selected fungi Eremothecium ashbyii and Nadsonia fulvescens. In addition, all four compounds were found to have no activity against Gram-positive and Gram-negative bacterial species. These biological results are essential to the understanding of how these types of complexes behave and show they are perfectly stable in the evaluated bio-environments. The results also indicate that these ligands and complexes may present themselves as excellent models for radiotoxicity studies using technetium-99m, but more specifically, rhenium Re-186 and Re-188. [ABSTRACT FROM AUTHOR]

In the conventional method of synthesis by using cyclohexylamine (CA) as template produces in the pore range of 0–3 nm. To enlarge the pore size which is suitable for biodiesel synthesis, the modified synthesis method is adopted by using CA as a template. In this novel method, pore size is enlarged to 7 nm. Cyclohexylamine was applied as a template for AlPO4 and AlSiO4 molecular sieves synthesis. In AlSiO4 synthesis, tetraethyl orthosilicate hydrolyzed to produce ethyl carbocation which is used for ethylation of CA in the presence of aluminum chloride. This ethylated CA size is large enough to produce a large pore size (7 nm). In AlPO4 two types of pore are produced with a pore size of 3 and 7 nm. The 3 nm are created by CA and 7 nm by the binding of CA with phosphoric acid. The synthesized materials are analyzed by physicochemical characterization. AlPO4 has a neutral framework, but the synthesized AlPO4 has acidity which is evidence for the CA binding with phosphoric acid. The synthesis of a promising catalyst (AlPO4-7 and AlSiO4-7) with an enlarged pore that can be effectively applied for the production of biodiesel from waste cooking oil (WCO) at room temperature. The acidity of the synthesized AlPO4 and AlSiO4 are 0.168 and 0.548 mmol/g. These catalysts are active at room temperature due to higher acidity. So the reaction takes place faster and it will reduce the reaction time. It is observed that AlSiO4 produces 90% biodiesel and AlPO4 produces 72% biodiesel with a shorter reaction time. This result reveals that 7 nm pores are suitable for biodiesel production. The diethyl ether selectivity of AlPO4 and AlSiO4 is 24% and 4%, respectively. This is due to the 3 nm pore size created by CA in AlPO4 and it favors diethyl ether synthesis. [ABSTRACT FROM AUTHOR]

Bridged nitrogen bicyclic skeletons have been accessed via unprecedented site‐ and diastereoselective orthogonal tandem catalysis from readily accessible reactants in a step economic manner. Directed Pd‐catalyzed γ‐C(sp3)‐H olefination of aminocyclohexane with gem‐dibromoalkenes, followed by a consecutive intramolecular Cu‐catalyzed amidation of the 1‐bromo‐1‐alkenylated product delivers the interesting normorphan skeleton. The tandem protocol can be applied on substituted aminocyclohexanes and aminoheterocycles, easily providing access to the corresponding substituted, aza‐ and oxa‐analogues. The Cu catalyst of the Ullmann‐Goldberg reaction additionally avoids off‐cycle Pd catalyst scavenging by alkenylated reaction product. The picolinamide directing group stabilizes the enamine of the 7‐alkylidenenormorphan, allowing further product post functionalizations. Without Cu catalyst, regio‐ and diastereoselective Pd‐catalyzed γ‐C(sp3)‐H olefination is achieved. [ABSTRACT FROM AUTHOR]

The protection for Al alloy is investigated through vapor phase assembly technology. The corrosion resistance performance of the assembled Al alloys is compared by the electrochemical measurements as well as hydrogen evolution test. The assembly sequence affects the protection of the complex films formed on Al alloy surface. It indicates that the complex films of base and acid assembly components have better protection effects. The reactivity between the assembly components and the formation mechanism of the complex films is analyzed. The alternative assembly of acid and base components enhances the anticorrosion ability of Al alloys and becomes the promising method for the use of the salt‐type volatile corrosion inhibitor. [ABSTRACT FROM AUTHOR]

In the present investigation, we undertake the study of molecular interaction in a ternary mixture of cyclohexylamine (CHA), ethanol (Eth) and benzene (B) theoretically as well as experimentally. We study the interaction between CHA dimer and complexes (Eth-CHA, B-CHA, CHA-Eth-B) theoretically using DFT (Density functional theory) in gas phase. It includes the quantum chemical calculations of interaction energy, bond length, and identification of the intermolecular interaction from structural parameter analysis and molecular orbital analysis. Further, we experimentally determine the excess thermo-acoustic parameters of the mixture. For this, we have measured the ultrasonic velocity (u) and density (p) of the ternary mixture of CHA+Eth+B and of pure components at 303 K, 308 K and 313 K temperature. From these experimental values of u and ?, excess thermo-acoustic parameters have been estimated using standard relations. The variations in excess acoustic parameters with the concentration of CHA (x1) are discussed in terms of the interactions and molecular geometry of the liquid mixture. At lower concentration, weak interactions dominate while on increasing x1 strong forces between molecules take place. The strong H-bonding interaction between CHA-ethanol molecules and molar volume differences of pure components leads to interstitial accommodation of molecules. The experimentally determined excess properties behaviour is supported by the theoretical calculation. [ABSTRACT FROM AUTHOR]

An ambient-curable hybrid resin (ACHR) terminated with trimethoxysilane functional groups, synthesized through a simple ring-opening reaction between 3-glycidyloxypropyltrimethoxysilane (KH560) and 4,4′-methylenebis (cyclohexylamine) (PACM), was applied to the surface of a transparent organic polymer to produce a robust, flexible, and transparent protective hybrid film, moisture cured at room temperature. The structure, morphology, and optical, mechanical, and thermal properties of the obtained hybrid film were evaluated. The hybrid film allowed the transmittance of more than 87% of visible light (at 600 nm), maintaining almost the same high transparency as bare PET film. The unique flexible segments and rigid segments in the inorganic–organic hybrid structure of the film realized superior resistance to bending and scratching. The hybrid film-coated PET demonstrated excellent flexibility, with an extremely low bending radius, illustrated by wrapping around a 1-mm mandrel bar without cracking. In addition, the hybrid film exhibited superior pencil hardness (of 2H) and excellent wear durability, i.e., no scratching after being subjected to 200 abrasion cycles using #0000 steel wool under a 19.6 kPa load. The robust, flexible, and transparent protective film developed here, and its simple and efficient preparation method, should have extensive application prospects. [ABSTRACT FROM AUTHOR]

The direct synthesis of cyclohexylamine via the hydrogenation of nitrobenzene over monometallic (Pd, Ru or Rh) and bimetallic (PdxRu1−x) catalysts was studied. The Pd0.5Ru0.5-PVP catalyst was the most effective catalyst for this reaction. The catalyst can be reused and applied for the synthesis of N-aryl pyrroles and quinoxalines from nitrobenzenes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Empirical models developed accurately translating the amination of cyclohexanol. • Multivariate linear regression by stepwise variable selection was employed. • Regression models can be used to accurately estimate catalyst performance indicators. • "Black-box" modelling can be used as a strategy for process development. Multivariate linear regression (MLR) models between the operating conditions and the performance parameters for the amination reaction of cyclohexanol (CHOL) with NH 3 as aminating agent and in the presence of H 2 , using a commercial Ni-based catalyst, were established. The regressors were chosen according to a stepwise variable selection approach so that only significant and non-redundant input variables were selected. The obtained models (related to CHOL conversion and yields for the more relevant products) were statistically significant with good fittings. Moreover, the models also reveal to act as good predictors, by cross validation and external validation. Nevertheless, models fitted to cyclohexyldeneaniline (CHONE) formation still present opportunities for improvement, given their poorer prediction performance. Sensitivity analysis of the developed models confirm the tendencies observed by Exploratory Data Analysis (EDA) indicating that the established relationships are able to translate the experimental observations. Therefore, the models can be used for process optimization purposes and scale-up methodologies. [ABSTRACT FROM AUTHOR]

The article offers information on several researches published in different science periodicals. Topics discussed include dipolar cycloaddition enabled the formation of the cyclohexyl core with tetrodotoxin; Boron arsenide is a semiconductor with several interesting properties, including a high thermal conductivity and systemic immune checkpoint blockade displays therapeutic efficacy in cancers, it induces immune-related adverse events that can undermine treatment.

Ni‐based catalysts present a highly interesting performance for the reductive amination of cyclohexanol (CHOL). The stability of a commercial Ni‐based catalyst was evaluated and a high stability over the tested time‐on‐stream (TOS) was observed. The reaction network was evaluated by analysis of selectivity profiles as a function of CHOL conversion. The formation of cyclohexylamine (CHA) was found to be consistent with the proposed borrowing hydrogen method (BHM). The formation of heavy‐end (HE) by‐products also follows the BHM pathway as parallel reaction. The effect of individual molar proportions of NH3 and H2 was evaluated. It was found that when H2 is present in a high excess, side reactions were favored, but its presence is mandatory towards keeping the catalyst active. [ABSTRACT FROM AUTHOR]

Background: Para-nitrophenyl phosphate, the common substrate for alkaline phosphatase (AP), is available as a cyclohexylamine salt. Here, we report that cyclohexylamine is a non-competitive inhibitor of APs. Methods: Cyclohexylamine inhibited four different APs. Co-crystallization with the cold-active Vibrio AP (VAP) was performed and the structure solved. Results: Inhibition of VAP fitted a non-competitive kinetic model (Km unchanged, Vmax reduced) with IC50 45.3 mM at the pH optimum 9.8, not sensitive to 0.5 M NaCl, and IC50 27.9 mM at pH 8.0, where the addition of 0.5 M NaCl altered the inhibition to the level observed at pH 9.8. APs from E. coli and calf intestines were less sensitive to cyclohexylamine, whereas an Antarctic bacterial AP was similar to VAP in this respect. X-ray crystallography at 2.3 Å showed two binding sites, one in the active site channel and another at the surface close to dimer interface. Antarctic bacterial AP and VAP have Trp274 in common in their active-sites, that takes part in binding cyclohexylamine. VAP variants W274A, W274K, and W274H gave IC50 values of 179 mM, 188 mM and 187 mM, respectively, at pH 9.8. Conclusions: The binding of cyclohexylamine in locations at the dimeric interface and/or in the active site of APs may delay product release or reduce the rate of catalytic step(s) involving conformational changes and intersubunit communications. General significance: Cyclohexylamine is a common chemical in industries and used as a counterion in substrates for alkaline phosphatase, a clinically important and common enzyme in the biosphere.