Covalent Functionalization of Pristine and Ga-Doped Boron Phosphide Nanotubes with Imidazole

Abstract

Density functional theory (DFT) calculations at the B3LYP/6–31G* level were performed to investigate covalent functionalization of imidazole on pristine (in gas and H₂O phases) and Ga-doped BPNT models in terms of energetic, geometric, and electronic properties. The results show that imidazole, as a functional group, prefers to be adsorbed via its nitrogen atom on the pristine, Ga_B, and Ga_P nanotube models. The adsorption energy of imidazole on the (6,0) zigzag BPNT in gas and solvent phases is ?0.76 and ?1.11 eV, respectively, and about 0.38 and 0.43 electron are transferred from the imidazole to nanotube in the phases. The presence of a polar solvent increases the electron donor of imidazole molecule. The results show that Ga doping can significantly enhance the adsorption energy of imidazole on the nanotube models to about 95%.

Moreover, the imidazole adsorption on the pristine and Ga-doped BPNT models has not significant changes in the energy gap of the nanotube models and it is slightly changed after covalent functionalization process. This study may provide new insight to the development of functionalized boron phosphide nanotubes for generation of the new hybrid compounds especially in drug delivery systems for virtual applications.     

N,N ′-Diiodo-N,N′-1,2-ethanediylbis(p-toluenesulfonamide) as an Efficient Catalyst for Acetylation of Alcohols,Phenols, Amines,and Thiols Under Solvent-Free Conditions

N,N′-Diiodo-N,N′-1,2-ethanediylbis(p-toluenesulfonamide) (NIBTS) is a highly efficient catalyst for the acetylation of alcohols, phenols, amines, and thiols under solvent-free conditions. Primary, secondary, tertiary alcohols; phenols; amines; and thiols can be easily acetylated in good to excellent yields at 80 °C.     

Synthesis of oxo-Phosphoranylidene Aminobenzoic Acid Derivatives by a Multicomponent Reaction

2-Aminobenzoic acids or 4-aminobenzoic acid react with dimethyl acetylenedicarboxylate/triphenylphosphine in less than 20 min at 15–25°C to produce new organic phosphorus compounds in good to excellent yields. The conversion occurs with selective N- over O-alkylation of the amino group and isolation of the products is accomplished simply by filtration.     

Ab Initio Study of Conformational Properties of Heteroatom-Containing 1,2-Bisketene Analogues

Abstract

Minimum-energy and transition-state geometries of 4-oxobuta-1,3-diene-1-thione, buta-1,3-diene-1,4-dithione, 4-selenoxobuta-1,3-diene-1-thione, 4-selenoxobuta-1,3-diene-1-one, and buta-1,3-diene-1,4-diselenone were calculated using HF, B3LYP, and MP2 levels of theory and 6–31 + G* basis set by rotation around the related ?C?C? single bonds. In all of the above-mentioned molecules, the s-trans conformation was obtained as the most stable conformer with the 180° dihedral angle. In buta-1,3-diene-1,4-dithione, 4-selenoxobuta-1,3-diene-1-thione, and buta-1,3-diene-1,4-diselenone, the s-cis form of these compounds corresponded to the other energy-minimum geometry. Their skew geometries, with torsional angles approximately 100°, were a transition state for conformational interconversion between the two global minima forms. In 4-oxobuta-1,3-diene-1-thione and 4-selenoxobuta-1,3-diene-1-one, geometries with the C?C?C?C dihedral angles about 51 and 43° (respectively) were attributed to the second energy-minimum geometry. Transition-state structures from both molecules were found in the torsional angles at about 0 and 100°.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT     

Regioselective Syntheses of 1-Aryl-substituted-5H-[1,3]thiazolo[3,2-a]quinazoline-5-ones During Sonogashira Coupling

Abstract

Reaction of 2-mercaptopropargylquinazoline-4-one with various aryliodides catalyzed by Pd–Cu leads to the regioselective formation of 1-arylsubstituted-5H-[1,3]thiazolo-[3,2-a]quinazoline-5-ones.

GRAPHICAL ABSTRACT      

NaBH4/DOWEX(R)50WX4: A Convenient Reducing System for Fast and Efficient Reduction of Carbonyl Compounds to Their Corresponding Alcohols

The reduction of a variety of carbonyl compounds was efficiently carried out with NaBH₄/DOWEX(R)50WX4 system. The reactions were performed to give the corresponding alcohols derivatives in perfect yields in THF at room temperature. Reduction of acyloins and a‐diketones by this reducing system produced efficiently the corresponding vicinal diols. Also, the reduction of aldehydes over ketones has been accomplished successfully by this system. Regioselectivity of this system was also investigated with exclusive 1,2‐reduction of conjugated carbonyl compounds to their corresponding allylic alcohols in high to excellent yields.     

Convenient Synthesis of 14‐Aryl‐14‐H‐dibenzo[a,j]xanthenes Catalyzed by Acyclic Brønsted Acidic Ionic Liquid [H—NMP]+[HSO4]− under Microwave Irradiation

Efficient method for direct preparation of 14‐aryl‐14‐H‐dibenzo[a,j]xanthenes through condensation of β‐naphthol with various aromatic aldehydes in the presence of the catalytic amount of [H—NMP]⁺[HSO₄]^? under microwave irradiation was described. This method has the advantages such as; very easy reaction workup, absolute separation of catalyst from the reaction mixture and smooth recyclability of catalyst. In this reaction 14‐aryl‐14‐H‐dibenzo[a,j]xanthenes were obtained as desired products in excellent yields and short reaction times via green and one‐pot procedure.     

Supported Nitric Acid on Silica Gel and Polyvinyl Pyrrolidone (PVP) as an Efficient Oxidizing Agent for the Oxidation of Urazoles and Bis-urazoles

A method for the oxidation of a good range of urazoles and bis-urazoles to the corresponding triazolinediones by supported nitric acid on silica gel (SiO₂-HNO₃) and/or polyvinyl pyrrolidone (PVP-HNO₃) is described. Reactions have been carried out heterogeneously at room temperature in dichloromethane with good to excellent yields.     

Solid phase extraction of Cd(II) and Pb(II) using a magnetic metal-organic framework, and their determination by FAAS

We describe a novel magnetic metal-organic framework (MOF) for the preconcentration of Cd(II) and Pb(II) ions. The MOF was prepared from the Fe₃O₄-pyridine conjugate and the copper(II) complex of trimesic acid. The MOF was characterized by IR spectroscopy, elemental analysis, SEM and XRD. A Box-Behnken design through response surface methodology and experimental design was used to identify the optimal parameters for preconcentration. Extraction time, amount of magnetic MOF and pH value were found to be critical factors for uptake, while type, volume, concentration of eluent, and elution time are critical in the elution step. The ions were then determined by FAAS. The limits of detection are 0.2 and 1.1 μg?L^?1 for Cd(II), and Pb(II) ions, respectively, relative standard deviations are <4.5% (for five replicates at 50 μg?L^?1 of Cd(II) and Pb(II) ions), and the enrichment capacity of the MOF is at around 190 mg?g^?1 for both ions which is higher than the conventional Fe3O4-pyridine material. The magnetic MOF was successfully applied to the rapid extraction of trace quantities of Cd(II) and Pb(II) ions in fish, sediment, and water samples.

Solubility Data of Diazepam in Binary and Ternary Mixtures of PEGs 200 and 400 with N-Methyl Pyrrolidone and Water at 298.2 K: Experimental Data and Modeling

Experimental solubilities of diazepam in binary and ternary solvents of polyethylene glycols 200 and 400 with N-methyl pyrrolidone and water at T = 298.2 K are reported. The Jouyban–Acree model was used to fit solubility data of diazepam in the binary and ternary solvent mixtures (106 data points) in which the overall mean relative deviations (OMRD %) is 13.1 % and the prediction OMRD % is 31.7 %. The combined version of the Jouyban–Acree model with Hansen solubility parameters was used for fitting and predicting the solubility data and the OMRDs % are 10.0 and 20.8 %, respectively. Also, the previously proposed trained versions of the Jouyban–Acree model were used for predicting the reported data in this work and all results are listed in the tables. The density of the solute-free solvent mixtures were measured and employed to calculate the constants of the Jouyban–Acree model and then the densities of the saturated solutions were predicted.