Tert-butylamine Research Articles

One pot synthesis of 4-iodo-3-phenylbenzo[b][1,6]naphthyridine via imino iodization-cyclization of alkynylquinoline-3-carbaldehydes

Simple, environmentally benign and metal free one pot strategy has been used for the synthesis of 4-iodo-3-phenylbenzo[b][1,6]naphthyridine from O-alkynylquinolinyl aldehydes with tert-butyl amine and iodine through imine formation in good to excellent yield at room temperature in aerobic and mild conditions. The beauty of this reaction is the imine formation and cyclization in the same reaction pot. Due to presence of iodine in product, it can be useful for further reaction and can be valuable synthon for new organic compounds.

Comparative description of the extraordinary phenomenon "thermally activated isobaric partial structure compaction" of water as a solute in some alkanols and alkylamines

This review summarises the data available in the literature. It also includes the authors' published results of precision densimetric measurements. The research concerns with the physically unusual phenomenon of "thermally activated isobaric partial densification of the structure" (TIPCS) of dissolved water, or its so-called "negative partial molar expandability" (NPEA) in several organic solvents. They contain amphiproton hydroxyl-containing media of three alcohols: methyl alcohol (MA), tertiary butyl alcohol (TBAlcohol), and amyl or pentyl alcohol (TPA), so asprotophilic media of two amines: tert butylamine (TBAmine) and ethylenediamine (EDA). The discussed TIPCS phenomenon, associated with a decrease in the standard (partial at infinite dilution) volume of solvated water with increasing temperature, was discovered about half a century ago in alkanol solutions of H2O and recently - in water-containing media of alkylamines. However, nowadays this extraordinary effect has not yet found its physically based interpretation. It allows ones to predict the possibility of TIPCS occurrence in the binary liquid-phase system specifically selected for the study. Our comprehensive data analysis allowed us to make several inferences regarding the main characteristics of a standard solution of H2O in an organic solvent. They cause extraordinary changes in the volume of the formed solvatocomplex of water under the influence of increasing temperature. Firstly, the energy parameters of the intermolecular interaction (relative affinity) water solvent noticeably dominate over those of the solvent-solvent interaction. Those differences become more evident with increasing temperature. Secondly, a higher rate of thermal expansion of the organic solvent structure in volume (inbulk) is found than influence of temperature on structural packing of the resulting mixed molecular aggregate or water solvates complex. Thirdly, the difference in the parameters of water-solvent and solvent-solvent interactions depends not only on the proton-donor/acceptor properties of the molecules contacting in solution, but also on the configuration of the structural packing of the solvating medium. It determines the nature of steric hindrances to the formation of H-bonds. Therefore, the absolute values of the mentioned parameters of relative affinity at 298.15 K increase in the series: MA << EDA ≈ TBAmine < TPAlcohol < TBAmine. It can indicate a relative strengthening of the specific interaction (mainly through the formation of hydrogen bonds) between the molecules of water and amphiprotonic or protophilic solvent in the above sequence. Indeed, difference in the solvent-solvent and water-solvent hydrogen bonding energies in the discussed liquid media of alkylamines (TBAmine and EDA) and tertiary isomeric alkanols (TBAlcohol and TPA) - with the most evident basicity - turned out to be noticeably larger than in the structural packing of water methanol solution. The ability of the components to specific interactions is quite comparable in those compounds.

Сравнительная характеристика неординарного явления «термоактивируемого изобарического парциального уплотнения структуры» воды как растворенного вещества в некоторых алканолах и алкиламинах

This review summarises the data available in the literature. It also includes the authors' published results of precision densimetric measurements. The research concerns with the physically unusual phenomenon of "thermally activated isobaric partial densification of the structure" (TIPCS) of dissolved water, or its so-called "negative partial molar expandability" (NPEA) in several organic solvents. They contain amphiproton hydroxyl-containing media of three alcohols: methyl alcohol (MA), tertiary butyl alcohol (TBAlcohol), and amyl or pentyl alcohol (TPA), so asprotophilic media of two amines: tert butylamine (TBAmine) and ethylenediamine (EDA). The discussed TIPCS phenomenon, associated with a decrease in the standard (partial at infinite dilution) volume of solvated water with increasing temperature, was discovered about half a century ago in alkanol solutions of H2O and recently - in water-containing media of alkylamines. However, nowadays this extraordinary effect has not yet found its physically based interpretation. It allows ones to predict the possibility of TIPCS occurrence in the binary liquid-phase system specifically selected for the study. Our comprehensive data analysis allowed us to make several inferences regarding the main characteristics of a standard solution of H2O in an organic solvent. They cause extraordinary changes in the volume of the formed solvatocomplex of water under the influence of increasing temperature. Firstly, the energy parameters of the intermolecular interaction (relative affinity) water solvent noticeably dominate over those of the solvent-solvent interaction. Those differences become more evident with increasing temperature. Secondly, a higher rate of thermal expansion of the organic solvent structure in volume (inbulk) is found than influence of temperature on structural packing of the resulting mixed molecular aggregate or water solvates complex. Thirdly, the difference in the parameters of water-solvent and solvent-solvent interactions depends not only on the proton-donor/acceptor properties of the molecules contacting in solution, but also on the configuration of the structural packing of the solvating medium. It determines the nature of steric hindrances to the formation of H-bonds. Therefore, the absolute values of the mentioned parameters of relative affinity at 298.15 K increase in the series: MA << EDA ≈ TBAmine < TPAlcohol < TBAmine. It can indicate a relative strengthening of the specific interaction (mainly through the formation of hydrogen bonds) between the molecules of water and amphiprotonic or protophilic solvent in the above sequence. Indeed, difference in the solvent-solvent and water-solvent hydrogen bonding energies in the discussed liquid media of alkylamines (TBAmine and EDA) and tertiary isomeric alkanols (TBAlcohol and TPA) - with the most evident basicity - turned out to be noticeably larger than in the structural packing of water methanol solution. The ability of the components to specific interactions is quite comparable in those compounds.

Successful controlled release of cyclophosphamide from tert-butylamine-functionalized large-pore SBA-15

ABSTRACT Controlled drug delivery systems operate effectively using the correct carrier/host design that respects the physicochemical characteristics of the drug. LP-SBA-15 shows exceptional qualities as a new host for cyclophosphamide (CP) delivery due to its low toxicity, high biocompatibility, and biodegradability in vivo. Cyclophosphamide is a phosphoramide-derived alkylating compound currently used for treating autoimmune diseases and slowing or restraining cancer cell growth. LP-SBA-15 was synthesized and functionalized using 0%–15%–25% tert-Butylamine (TBA) to incorporate the drug. The composite was characterized by XRD, N2 physisorption, UV-VIS, and FTIR spectroscopy. Absorption and release of CP were assessed by UV-VIS spectrophotometry. The release mechanism from the functionalized LP-SBA-15 matrix was evaluated by fitting experimental data with different mathematical models. The Ritger – Peppas, Weibull, and First-Order models were the most appropriate, as confirmed by the coefficient of determination R2 and other statistics. We designed LP-SBA-15 functionalized with 15% TBA as a suitable system that achieves a moderate initial release rate and maintains a constant rate over long periods, enabling the nanodrug (CP) to concentrate on tumor tissue and not on normal cells while simultaneously reaching adequate levels over time and avoiding harmful side effects due to their deposition.

Mechanistic Insights into Nitrile Activation by Cobalt(III)-Hydroperoxo Intermediates: The Influence of Ligand Basicity.

The versatile applications of nitrile have led to the widespread use of nitrile activation in the synthesis of pharmacologically and industrially valuable compounds. We reported the activation of nitriles using mononuclear cobalt(III)-hydroperoxo complexes, [CoIII(Me3-TPADP)(O2H)(RCN)]2+ [R = Me (2) and Ph (2Ph)], to form cobalt(III)-peroxyimidato complexes, [CoIII(Me3-TPADP)(R-C(=NH)O2)]2+ [R = Me (3) and Ph (3Ph)]. The independence of the rate on the nitrile concentration and the positive Hammett value of 3.2(2) indicated that the reactions occur via an intramolecular nucleophilic attack of the hydroperoxide ligand to the coordinated nitrile carbon atom. In contrast, the previously reported cobalt(III)-hydroperoxo complex, [CoIII(TBDAP)(O2H)(CH3CN)]2+ (2TBDAP), exhibited the deficiency of reactivity toward nitrile. The comparison of pKa values and redox potentials of 2 and 2TBDAP showed that Me3-TPADP had a stronger ligand field strength than that of TBDAP. The density functional theory calculations for 2 and 2TBDAP support that the strengthened ligand field in 2 is mainly due to the replacement of two tert-butyl amine donors in TBDAP with methyl groups in Me3-TPADP, resulting in the compression of the Co-Nax bond lengths. These results provide mechanistic evidence of nitrile activation by the cobalt(III)-hydroperoxo complex and indicate that the basicity dependent on the ligand framework contributes to the ability of nitrile activation.

Facile synthesis of lanthanum-doped SrTiO3 nanocubes mediated by cetyltrimethylammonium bromide and tert-butylamine under solvothermal condition and their tunable electrical properties

The electrical conductivity of low concentrations of lanthanum-doped SrTiO3 nanocube ceramics synthesized using the facile solvothermal method in mixed organic and inorganic solvents with cetyltrimethylammonium bromide (CTAB) as a capping agent and tert-butyl amine (TBA) as a mineralizer was investigated. X-ray diffraction patterns confirmed the formation of a high-purity perovskite phase, corresponding to the standard data and the pattern refinement results. The particles of the sample were nanocubes, whereas the La-doped SrTiO3 sample particles were more uniform in size and shape, as shown in TEM images. The FT-IR spectrum confirmed the vibration of the CH3-N+ groups from CTAB and TBA, indicating an electrostatic interaction between their functional groups and the particle surface. Substitution of La3+ ions at low concentrations increased electrical conductivity compared to the undoped SrTiO3 sample. Lanthanum donates excess electrons, thereby increasing the number of electron carriers, which causes a reduction in the band gap energy according to the UV-DRS spectrum analysis using the Tauc equation.

Catalytic amination of diethylene glycol with tert‑butylamine to tertiarybutylaminoethoxyethanol over NiCu/Al2O3 catalysts: Facilitation of NiCu alloy

Herein, a series of NiCu/Al2O3 catalysts were prepared by impregnation method and subsequent thermal treatment under different reduction temperatures. The catalysts exhibited excellent catalytic activity for the amination of diethylene glycol (DEG), and satisfactory yield of tertiarybutylaminoethoxyethanol (TBEE) could be obtained. XRD, N2 adsorption-desorption, SEM, TEM, XPS, and H2-TPR were employed to characterize the catalysts, the interaction between Ni and Cu on the catalytic activity was studied. It was found that NiCu alloy was formed after catalyst reduction, which strengthened the reduction ability of NiO and increased the number of Ni0 active center, contributing to the enhanced catalytic activity. Moreover, the effects of reaction parameters on catalytic activity were explored. There was no need for a solvent, only 3 molar equivalents of tert‑butylamine (TBA) and 1 wt.% catalyst was required. After 7 h of reaction at 220 °C, satisfactory conversion (89.6%) and selectivity (84.6%) were obtained over the prepared catalyst. Cycle experiment demonstrated that the prepared catalyst retained excellent stability and reusability after six runs without significant loss of catalytic activity. This work provided an efficient catalyst for the catalytic amination of diethylene glycol with tert‑butylamine to TBEE.

Highly selective discriminating E, E/E, Z isomers of functionalized 1-phenyl-2,5-divinyl-1H-pyrrole for n-/sec-/tert-butyl amines and as temperature sensor

A series of novel E, E/E, Z isomers based on 5-(2-cyano-3-ethoxy-3-oxoprop-1-en-1-yl)-1H-pyrrol-2-yl acrylic acid have been successfully synthesized. The comparative studies between compounds presenting E, E/E, Z isomers on the properties of emission and effects of temperature had been discussed. Interestingly, the E, Z, and E, E isomers emitted different luminous colors and aggregation-induced emission (AIE) properties. Notably, the E, Z-OC2H5COOH and E, E-OC2H5COOH loaded on filter paper could identify alkaline compounds. Furthermore, E, E-OC2H5COOH strips could selectively discriminate for n-/sec-/tert-butylamine by changing the color of the fluorescence. In addition, E, E-OC2H5COOH, doped into polymer dimethyl silicone (PDMS) film could exhibit an evident change in emission color from orange to yellow at 90 °C and gradually vanished at 190 °C, while that of E, Z-OC2H5COOH didn't change significantly with heating. Therefore, the configuration of two double bonds can be used to regulate the change of fluorescence, improve the chemical and physical properties of materials, and break through the deficiency of single configuration regulation.

Hydrogen bonding guest-water interactions in pinacolone, tert-butyl amine, and tert-butylmethyl ether: a theoretical study on energetics, structure, and topological +

In guest-host interactions, guest molecules used for hydrogen bonding potential of clathrate hydrate cages are involved as "promoters" for hydrogen or methane storage. Among the promoter molecules, there are pinacolone and tert-butylmethyl ether containing oxygen atom, and tert-butyl amine among those containing nitrogen atom. The dimer and trimer interactions of these molecules with the water clusters were investigated. The cooperativity effect, which is a measure of the hydrogen bonding of these oxygen and nitrogen-containing complexes, was calculated and these complexes were analyzed. Moreover, molecular electrostatic potential (MEP) analysis was performed to determine intermolecular interactions. Clusters of several molecules may seem like a non-significant state of matter; however, in systematic studies with small clusters, important results can be obtained. Therefore, it is very useful to work with clusters to understand the properties of the dense phase, and this study aimed to examine the properties of structures, energies, infrared vibration frequencies, and topological parameters, which develop as a result of the interaction of structures in different clusters with water molecules. The MP2 level was performed using aug-cc-pVDZ basis set calculations for this study. Tight converting criteria were used in the optimization step. Harmonic vibrational modes were calculated at the MP2/aug-cc-pVDZ level. Each minima obtained from the MP2 level was subjected to single-point energy calculations using CCSD(T) levels with the aug-cc-pVDZ basis set by the Gaussian16 package program suite. Thetopological analyseswere performed withnon-covalent interaction (NCI). MEP surface of the complex was also composed by Gaussian program using the optimized geometry at a MP2/aug-cc-pvdz level.

Method development for simultaneous estimation of Amlodipine Besylate and Perindopril Tertbutyl amine in fixed-dose

The fixed-dose combination of Amlodipine Besylate (ADB) with Perindopril Tertbutylamine (PTBA) drug is used to treat patients with mild-to-moderate hypertension. In recent times researchers are interested to find the efficient analytical method development and validation for the simultaneous determination of ADB and PTBA in a fixed-dose, film-coated tablet. Therefore, the current study was performed with a reverse-phase liquid chromatography method developed to simultaneously analyze ADB and PTBA in film-coated tablets as fixed-dose combinations. The linearity of the proposed method was calculated by preparing six different mixtures of both ADB and PTBA in the mobile phase. The concentration of both the analytes was analyzed at 56mg/100 mL to 84mg/100 mL and 32mg/100 mL to 48mg/100 mL, respectively. The ratio of acetonitrile and phosphate buffer was 35:65. The flow rate was adjusted to 1.5 ml per minute to reduce the retention time. The validation study was performed for the parameters specificity, linearity, precision, range, limit of detection, limit of quantification, accuracy/biasness, and robustness. The relative percentage standard deviation for Perindopril Tertbutyl amine was 0.148%, and for Amlodipine is 0.312%. These results show that the advanced analysis method for simultaneous analysis of fixed-dose is precise. The theoretical IR spectra were also calculated by Gaussian 9.2 by employing the B3LYP functional at density functional theory (DFT) level study. All these parameters studied in this work authenticate the effectiveness of the developed validation method and ensure its repeatability/reproducibility accordingly. To the best of our knowledge, this is the first time to develop a new fast, and easy method for simultaneous identification and quantification of ADB and PTBA by high-performance liquid chromatography (HPLC) with a time-efficient and cost-effective approach.

Nickel Boride (NixB) Nanocrystals: From Solid-State Synthesis to Highly Colloidally Stable Inks

Metal borides, a class of materials intensively used in industry as superconductors, magnetic materials, or hot cathodes, remain largely unexplored at the nanoscale mainly due to the difficulty in synthesizing single-phase nanocrystals. Recent works have shown that synthetic methods at lower temperatures (<400 °C) yield amorphous polydisperse nanoparticles, while phase purity is an issue at higher temperatures. Among all the metal-rich borides, nickel borides (NixB) could be a potential catalyst for a broad range of applications (hydrogenations, electrochemical hydrogen, and oxygen evolution reactions) under challenging conditions (such as high pH or high temperatures). Here, we report a novel solid-state method to synthesize NixB nanopowders (with a diameter of approximately 45 nm) and their conversion into colloidal suspensions (inks) through treatment of the nanocrystal surface. For the solid-state synthesis, we used commercially available salts and explored the reaction between the Ni and B sources while varying the synthetic parameters under mild and solvent-free reaction conditions. We show that pure phase Ni3B and Ni2B NCs can be obtained with high yield in the pure phase using as precursors NiCl2 and Ni, respectively. Through extensive mechanistic studies, we show that Ni nanoclusters (1–2 nm) are an intermediate in the boriding process, while the metal co-reactant lowers the decomposition temperature of NaBH4 (used as a reducing agent and B source). Size control can instead be exerted through reaction mediators, as seen from the differential nucleation and growth of Ni (clusters) or NixB NCs when employing L- (amine, phosphine) and X-type (carboxylate) mediators. Applying surface engineering methods to our NixB NCs, we stabilized them with inorganic (NOBF4) or organic (borane tert-butyl amine, oleylamine) ligands in the appropriate solvent (DMSO, hexane). With this method, we produce stable inks for further solution processing applications. Our results provide tools for further development of catalysts based on NixB NCs and pave the way for synthesizing other metal boride colloidal nanostructures.

Application of GC-MS and LC-MS techniques for direct analysis of amines in pharmaceutical substances

Organic volatile chemicals such as amines are often not completely removed by practical manufacturing techniques and consequently their low levels are present in most pharmaceuticals. Based on good manufacturing practices and for the safety of the patients the level of hazardous for human health amines in pharmaceuticals have to be strictly controlled. Moreover, analysis of volatile amines in drug product has become recently an emerging topic of interest for analytical chemists since such residual impurities as: secondary amines, tertiary amine and other amine derivatives (in certain condition) have been reported to be a precursors of carcinogenic N-nitrosamines (NAs). In this study we present five new methods for control of such amines as: tert-butylamine (TBA), pyrrolidine, 4-fluoroaniline (4-FA), diisopropyl-ethylamine (DIPEA) and tetrabutylammonium hydrogensulfate (TBAHS) in pharmaceutical active ingredients (APIs) using GC-MS and LC-MS techniques. The validations results clearly demonstrate that the analytical procedures are suitable for their intended purpose. All revealed validations results meet the requirements of the ICH Q2R1 validation guidelines and the Q3A R2 guideline for residual impurities.

Ultra-high resolution near-infrared spectrum by wavelet packet transform revealing the hydrogen bond interactions

Resolution is always an obstacle to analyzing the fine structure of a spectrum. The problem is particularly serious in the analysis of the near-infrared (NIR) spectra of aqueous solutions, because the spectrum is generally composed of overlapping broad peaks making the understanding of the structures and the interactions notoriously difficult. In this work, wavelet packet transform (WPT) was adopted to enhance the resolution of the NIR spectra of aqueous mixtures. Due to the microscopic ability of WPT in both position and frequency, the fine details of a spectrum can be observed in the spectral components of different frequencies obtained by WPT decomposition. Ultra-high resolution spectrum can be obtained from the high-frequency component representing the spectral features. Spectral features of different hydrogen-bonded OH, as well as the OH in HOH and HOD, were identified from the high-resolution NIR spectra of water and heavy water mixtures and validated by the variation of the spectral intensity with the mole ratio of H2O and D2O. The high-resolution spectrum was further applied in analyzing the interaction of amine and water. The spectral features of the hydrogen bonding between CH/NH in tert-butylamine (TBA) and OH in water were observed. The structures of CH bonded to one water molecule, and the structures of NH connecting with one and two water molecules were identified.

Tunable morphology of strontium titanate nanocubes controlled by tert-butylamine-assisted solvothermal method and their enhanced electrical conductivity

The exploration of the size and shape of well-defined strontium titanate (SrTiO3) nanocubes remains challenging despite the increasing interest in this material, owing to its remarkable morphology-dependent electron and phonon transport abilities. This paper discusses the controllable solvothermal synthesis of SrTiO3 nanocube with tunable morphology in the ethanol-water solvent, using cetyltrimethylammonium bromide (CTAB) as a capping agent and tert-butylamine (TBA) as a mineralizer. The SrTiO3 nanocubes crystallization can be described as the dissolution-precipitation process, and the addition of CTAB and TBA affects the transformation of oriented attachment in forming a well-defined nanocube. In this study, the X-Ray Diffraction (XRD) data supported by the Le Bail refinement analysis revealed the shape-dependent tuning in lattice parameters of polycrystalline samples. The electrostatic interaction of CTAB and TBA on the particle surface of SrTiO3 was proven by the appearance of specific absorption peaks in the IR spectrum. XPS spectra show the chemical shift toward higher binding energy confirming the attraction of the nitrogen N-containing groups from CTAB and TBA with SrTiO3 through the synergistic capping effect. Meanwhile, HRTEM images showed that the nanocube particles have a uniform shape, sharp edges and vertices, flat faces, and narrow size distribution. In addition, the electrical conductivity in the bulk samples with uniform nanocubes increases three-fold compared to non-uniform nanocubes. These findings can potentially set a foundation for establishing synthesis techniques for producing morphologically-distinct particles based on surface interactions through the selective adsorption of additives.

Tailoring the permeability and flux stability of forward osmosis membrane with tert-butylamine functionalized carbon nanotubes for paracetamol removal

The discharge of pharmaceutical wastewater is an adversity to the nature. Some of the pharmaceutical product (PP) wastes are highly resistant towards bio-degradation hence physical-based separation technology such as forward osmosis (FO) has been introduced for the treatment. Despite exhibiting high water flux, commercial FO membrane often suffers from fouling and unsatisfactory solute rejection. In this study, carbon nanotubes (CNT) which has high self-bundling tendency was functionalized with tert-butylamine (TBA), a bulky tertiary amine. The agglomeration of the aminated CNT was suppressed via steric hindrance and surface charge repulsion. The nanofillers was then incorporated into the polyamide (PA) layer of thin film nanocomposite (TFN) during interfacial polymerization process to provide the required hydrophilicity and surface charges. Using synthetic paracetamol (PCT) solution as the feed solution (FS), the experimental outcome showed that the incorporation of amino-functionalized CNT (ACNT) successfully enhanced the hydrophilicity and flux stability of the FO membranes. Compared to the control thin film composite (TFC) membrane, ACNT-TFN membrane exhibited an improved water flux from 3.58 L.m−2.h−1 to 9.01 L.m−2.h−1, without sacrificing the PCT rejection (99.7 %). This study improves the understanding on the superior benefits of FO for enhancing the pharmaceutical waste removal and stimulates insight for more nanofillers-induced modification on the FO membrane, in order to make it truly useful for more water separation applications in the future.

Tuning the morphology of SrTiO3 nanocubes and their enhanced electrical conductivity

Strontium titanate (SrTiO3) nanocubes were prepared via the solvothermal method in an isopropanol-water system, using cetyltrimethylammonium bromide (CTAB) as a capping agent and tert-butylamine (TBA) as a mineralizer. We found that the presence of TBA produced a synergistic effect in the nucleation and growth of SrTiO3 in the solution, which enabled control over the formation of well-defined cubic particles. X-ray diffraction patterns of SrTiO3, synthesized with the addition of 1 mol of TBA, showed a perovskite structure with high crystallinity. The presence of specific absorption peaks in the fourier-transform infrared (FTIR) spectrum confirmed the existence of CTAB and TBA on the surface of the particles. Transmission electron microscope (TEM) images showed that the sharp-edged cubic particles had narrow size distributions, and selected area electron diffraction (SAED) patterns indicated a high crystallinity. An increase in electrical conductivity values was found in the bulk samples with regular nanocube particles compared to those of non-regular nanocubes.

Preliminary growth of metallic co films by thermal atomic layer deposition using RCpCo(CO)2 and alkylamine precursors

ALD-metallic films are typically deposited with assistant of plasma due to lack of suitable reducing co-reactants. In this work, we propose to use RCpCo(CO)2, a cobalt precursor with cyclopentadienyl (Cp) ligand (R = H) or its trimethylsilylderivative (R = TMS), and tert-Butyl amine (tBuNH2) as co-reactant to grow metallic Co films by thermal atomic layer deposition (T-ALD). The influence of Co precursor type, substrate type and thermal treatment on the film growth, composition, and phase structure of the Co films was investigated. The results show that the ALD-Co processes exhibit similar temperature window from 275 °C to 325 °C, and the growth rate of Co films deposited from CpCo(CO)2 on Si substrate is about 0.045 nm/cycle, which is higher than that of using TMSCpCo(CO)2 (0.03 nm/cycle). Thermal annealing and Pt substrate can promote the crystallization and growth of Co crystals. The ALD-Co films grown by CpCo(CO)2 showed relatively low resistivity of 10.6 μΩ·cm and considerable conformality, indicating a significant application potential.

Thermal Stability and Radiation Tolerance of Lanthanide-Doped Cerium Oxide Nanocubes

The thermal and radiation stability of free-standing ceramic nanoparticles that are under consideration as potential fillers for the improved thermal and radiation stability of polymeric matrices were investigated by a set of transmission electron microscopy (TEM) studies. A series of lanthanide-doped ceria (Ln:CeOx; Ln = Nd, Er, Eu, Lu) nanocubes/nanoparticles was characterized as synthesized prior to inclusion into the polymers. The Ln:CeOx were synthesized from different solution precipitation (oleylamine (ON), hexamethylenetetramine (HMTA) and solvothermal (t-butylamine (TBA)) routes. The dopants were selected to explore the impact that the cation has on the final properties of the resultant nanoparticles. The baseline CeOx and the subsequent Ln:CeOx particles were isolated as: (i) ON-Ce (not applicable), Nd (34.2 nm), Er (27.8 nm), Eu (42.4 nm), and Lu (287.4 nm); (ii) HMTA-Ce (5.8 nm), Nd (6.6 nm), Er (370.0 nm), Eu (340.6 nm), and Lu (287.4 nm); and (iii) TBA-Ce (4.1 nm), Nd (5.0 nm), Er (3.8 nm), Eu (7.3 nm), and Lu (3.8 nm). The resulting Ln:CeOx nanomaterials were characterized using a variety of analytical tools, including: X-ray fluorescence (XRF), powder X-ray diffraction (pXRD), TEM with selected area electron diffraction (SAED), and energy dispersive X-ray spectroscopy (EDS) for nanoscale elemental mapping. From these samples, the Eu:CeOx (ON, HMTA, and TBA) series were selected for stability studies due to the uniformity of the nanocubes. Through the focus on the nanoparticle properties, the thermal and radiation stability of these nanocubes were determined through in situ TEM heating and ex situ TEM irradiation. These results were coupled with data analysis to calculate the changes in size and aerial density. The particles were generally found to exhibit strong thermal stability but underwent amorphization as a result of heavy ion irradiation at high fluences.

Refractive Indices of Aqueous Solutions of Isomeric Butylamines at 303.15 K: Experimental and Correlative Approach

Refractive indices () and densities (r) of water (W) + n-butylamine (NBA), + sec-butylamine (SBA) and + tert-butylamine (TBA) systems had been measured in the whole range of composition at 303.15 K, from which deviation in refractive index (DnD ) molar refraction (Rm) and excess molar refraction () had been evaluated. All of the derived properties were fitted to appropriate polynomials. DnD were fitted to the Redlich-Kister polynomial equation. Values of DnD were all positive and were all negative which were attributed to cross hydrogen bonding, specific interactions as well as interstitial accommodation effect. A comparative study of Lorentz-Lorenz (L-L), Weiner (W), Heller (H), Gladstone-Dale (G-D), Arago-Biot (A-B), Eykman (Eyk), Newton (Nw), Eyring-John (E-J) and Oster (Os) relations for determining the refractive index of a liquid had been carried out to test their validity for the three binaries over the entire mole fraction range of butylamines at 303.15 K.

Discovery of BMS-753426: A Potent Orally Bioavailable Antagonist of CC Chemokine Receptor 2.

To improve the metabolic stability profile of BMS-741672 (1a), we undertook a structure-activity relationship study in our trisubstituted cyclohexylamine series. This ultimately led to the identification of 2d (BMS-753426) as a potent and orally bioavailable antagonist of CCR2. Compared to previous clinical candidate 1a, the tert-butyl amine 2d showed significant improvements in pharmacokinetic properties, with lower clearance and higher oral bioavailability. Furthermore, compound 2d exhibited improved affinity for CCR5 and good activity in models of both monocyte migration and multiple sclerosis in the hCCR2 knock-in mouse. The synthesis of 2d was facilitated by the development of a simplified approach to key intermediate (4R)-9b that deployed a stereoselective reductive amination which may prove to be of general interest.