Showing papers in "Canadian Journal of Chemistry in 2017"
TL;DR: In this paper, the adsorption of crystal violet (CV) dye onto magnetic alginate (MAlg) composite from aqueous solutions was studied, and experiments were carried out as function of contact time, dosage, temperature, etc.
Abstract: The adsorption of crystal violet (CV) dye onto magnetic alginate (MAlg) composite from aqueous solutions was studied. Experiments were carried out as function of contact time, dosage, temperature, ...
59 citations
TL;DR: The Truce-Smiles rearrangement is an X → C aryl migration reaction that is achieved by an intramolecular nucleophilic aromatic substitution pathway as mentioned in this paper.
Abstract: The Truce–Smiles rearrangement is an X → C aryl migration reaction that is achieved by an intramolecular nucleophilic aromatic substitution pathway. The reaction exhibits a wide substrate scope with respect to a migrating aryl ring and leaving group, appearing in many different tandem reaction sequences, to achieve a wide variety of product outcomes. We present an extensive survey of reported examples of the Truce–Smiles rearrangement from the chemistry literature (1950s until present) organized by various substrate design variables or aspects of the reaction method. Present deficiencies in our understanding of the reaction are identified with recommendations for future research directions and useful developments in the application of the reaction are celebrated.
50 citations
TL;DR: A brief summary of zethrene chemistry after the pioneering works by Clar, Mitchell, Sondheimer, and Staab et al. as mentioned in this paper is given in the introduction of this paper.
Abstract: This paper gives a brief summary of zethrene chemistry after the pioneering works by Clar, Mitchell, Sondheimer, and Staab et al. In the past a few years, various synthetic methods and stabilizing ...
48 citations
TL;DR: The molecular bis-(tris(carbene)borate) manganese (IV) complex [{PhB(MeIm)3}2Mn](OTf)2 shows 2Eg → 4A2g luminescence at 828 nm in the solid state at 85 K; this wavelength is longer by approximately...
Abstract: The molecular bis-(tris(carbene)borate) manganese(IV) complex [{PhB(MeIm)3}2Mn](OTf)2 shows 2Eg → 4A2g luminescence at 828 nm in the solid state at 85 K; this wavelength is longer by approximately ...
45 citations
TL;DR: In this review, promising results using dendrimer vehicles to deliver ocular drugs through different routes of administration have been reported, with emphasis on the d endrimer modifications used to target different ocular structures.
Abstract: Existing methods of administering ocular drugs are limited in either their safety or efficiency. Nanomedicine therapies have the potential to address this deficiency by creating vehicles that can control drug biodistribution. Dendrimers are synthetic polymeric nanoparticles with a unique highly organized branching structure. In recent years, promising results using dendrimer vehicles to deliver ocular drugs through different routes of administration have been reported. In this review, we briefly summarize these results with emphasis on the dendrimer modifications used to target different ocular structures.
44 citations
TL;DR: In this article, the authors compute general Randic, first general Zagreb (GZG), generalized ZG, multiplicative ZGG, additive ZG and geometric arithmetic (GA) indices for the rhombus silicate (RS) networks.
Abstract: For a molecular graph, a numeric quantity that characterizes the whole structure of a graph is called a topological index. In the studies of quantitative structure – activity relationship (QSAR) and quantitative structure – property relationship (QSPR), topological indices are utilized to guess the bioactivity of chemical compounds. In this paper, we compute general Randic, first general Zagreb, generalized Zagreb, multiplicative Zagreb, atom-bond connectivity (ABC), and geometric arithmetic (GA) indices for the rhombus silicate and rhombus oxide networks. In addition, we also compute the latest developed topological indices such as the fourth version of ABC (ABC4), the fifth version of GA (GA5), augmented Zagreb, and Sanskruti indices for the foresaid networks. At the end, a comparison between all the indices is included, and the result is shown with the help of a Cartesian coordinate system.
36 citations
TL;DR: In this article, the chemical graphs of carbon graphite and crystal structure of cubic carbon were studied and closed formulas of degree-based additive topological indices, mainly the first and second Zagreb index, general Randic index, atom bond connectivity index, geometric arithmetic index, fourth atom-bond connectivity index and fifth geometric algebraic index were given.
Abstract: Graph theory plays a vital role in modeling and designing any chemical structure or chemical network. Chemical graph theory helps in understanding the molecular structural properties of a molecular graph. The molecular graph consists of atoms called vertices and chemical bonds between atoms called edges. In this article, we study the chemical graphs of carbon graphite and crystal structure of cubic carbon. Moreover, we compute and give closed formulas of degree-based additive topological indices, mainly the first and second Zagreb indexes, general Randic index, atom bond connectivity index, geometric arithmetic index, fourth atom bond connectivity index, and fifth geometric arithmetic index of carbon graphite denoted by CG(m, n) for t levels, and crystal structure cubic carbon denoted for n levels.
35 citations
TL;DR: In this paper, the one-step π-extension of corannulene was achieved using a palladium-catalyzed C-H coupling reaction, and the X-ray crystal structure and photophysical properties of the thus formed phenanthro[9,10]-a...
Abstract: The one-step π-extension of corannulene was achieved using a palladium-catalyzed C–H coupling reaction. The X-ray crystal structure and photophysical properties of the thus formed phenanthro[9,10-a...
33 citations
TL;DR: In this article, modified ZnO nanoparticles were used to enhance the removal rate of the methylene blue (MB) dye, and they were modified by coating their surface with Congo red (CR) dye.
Abstract: This research aims to use modified ZnO nanoparticles to enhance the removal rate of the methylene blue (MB) dye. ZnO nanoparticles are modified by coating their surface with Congo red (CR) dye, hen...
27 citations
TL;DR: It is worth emphasizing that some peptide dendrimers show activity per se, with the use of targeting peptides or other specific groups that direct the drug/bioactive compounds to specific organs is an important trend in the search for better drug delivery systems.
Abstract: Dendrimers are versatile hyperbranched molecules, which have deserved attention especially for their potential in many applications, including biological. Peptide dendrimers comprise interesting cl...
27 citations
TL;DR: In this article, the authors synthesized thiophene-functionalized pyrene, peropyrene, and teropyrene through a two or four-fold alkyne annulation reaction promoted by triflic acid.
Abstract: We synthesized thiophene-functionalized pyrene, peropyrene, and teropyrene through a two- or four-fold alkyne annulation reaction promoted by triflic acid. All of the target compounds were fully characterized spectroscopically, and the structure of the peropyrene analogue was unambiguously confirmed by X-ray crystallography. A significant red shift in the absorption and emission properties as a function of extended conjugation was observed by UV–vis and fluorescence spectroscopy. This alkyne annulation strategy is a useful method for the conversion of smaller polycyclic aromatics to larger ones, such as nanographenes.
TL;DR: In this article, the sulfur-containing cycloparaphenylene (CPP) derivatives were synthesized by the platinum-mediated assembly of bismetallated DBT and DBTO and the subsequent reductive elimination of platinum.
Abstract: Cyclic tetramers of 3,7-dibenzo[b,d]thiophene (DBT) and 3,7-dibenzo[b,d]thiophene-5,5-dioxide (DBTO), i.e., [4]cyclo-DBT ([4]CDBT) and [4]cyclo-DBTO ([4]CDBTO), respectively, are synthesized by the platinum-mediated assembly of bis-metallated DBT and DBTO and the subsequent reductive elimination of platinum. This is the first example of the synthesis of sulfur-containing cycloparaphenylene (CPP) derivatives. The structure of [4]CDBTO is unambiguously determined by the single crystal X-ray analysis. Theoretical and experimental analyses of their physical properties reveal the effect of the sulfur atom and sulfonyl group at the periphery of biphenyl units of the CPP.
TL;DR: In this paper, a quantitative description for the interaction of Cu(I) with poly(styrene-co-maleic anhydride) modified with 4-aminopyridine (denoted as CuI/SMI complex) is presented using density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) approaches.
Abstract: A quantitative description for the interaction of Cu(I) with poly(styrene-co-maleic anhydride) modified with 4-aminopyridine (denoted as CuI/SMI complex) is presented using density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) approaches. Topological analysis of electron density revealed the existence of effective interactions between Cu(I) ions and the nitrogen in the pyridine ring. Interestingly, the results also showed that there is considerable interaction between Cu(I) and the oxygen of the carbonyl motif in the SMI ligand. Thus, CuI/SMI was examined as a heterogeneous and recyclable catalyst in Hantzsch pyridine synthesis under solvent-free conditions, affording diverse 1,4-dihydropyridines (1,4-DHPs) in excellent yields with relatively short reaction times.
TL;DR: In this article, a review summarizes the preparation and applications of 1D HAP materials, and discusses different aspects of 1-DHAP materials for biomedical applications, and various synthetic methods have been developed to prepare 1D hAP materials with different morphologies, sizes, surface properties and crystallinities.
Abstract: As one of the biominerals, hydroxyapatite (HAP) plays important roles in biology, and inspires researchers to investigate HAP-based materials for the applications in various biomedical fields. Among them, one-dimensional (1-D) micro-/nanostructured HAP materials have attracted great interest in the last decades. This review summarizes the preparation and applications of 1-D HAP materials, and discusses different aspects of 1-D HAP materials. Various synthetic methods have been developed to prepare 1-D HAP materials with different morphologies, sizes, surface properties and crystallinities. In addition, elements-substituted 1-D HAP materials and composites have also been prepared. Surfactants and additives are usually adopted to control the nucleation and growth of 1-D HAP materials, but the related mechanisms are not very clear yet. The applications of 1-D HAP materials have been widely investigated, and the biomedical applications show great prospect but still need further improvements. A new kind of hig...
TL;DR: Fluorescence spectroscopy is used to measure the binding affinity and provide new insights into the binding mechanism of cocaine and quinine with the cocaine-binding DNA aptamer to observe quenching of ligand fluorescence upon binding of the aptamer.
Abstract: We used fluorescence spectroscopy to measure the binding affinity and provide new insights into the binding mechanism of cocaine and quinine with the cocaine-binding DNA aptamer. Using the intrinsi...
TL;DR: In this article, the authors consider the irregularity measures of chemical molecular graphs, such as TUC4C8(S), TUC 4c8(R), zigzag TUHC6, tUC4, Armchair TUVC6, then dendrimers Tk,d, and the circumcoronene series of benzenoid Hk.
Abstract: Measures of the irregularity of chemical graphs could be helpful for QSAR/QSPR studies and for the descriptive purposes of biological and chemical properties such as melting and boiling points, toxicity, and resistance. Here, we consider the following four established irregularity measures: the irregularity index by Albertson, the total irregularity, the variance of vertex degrees, and the Collatz–Sinogowitz index. Through the means of graph structural analysis and derivation, we study the above-mentioned irregularity measures of several chemical molecular graphs that frequently appear in chemical, medical, and material engineering, as well as the nanotubes: TUC4C8(S), TUC4C8(R), zigzag TUHC6, TUC4, Armchair TUVC6, then dendrimers Tk,d, and the circumcoronene series of benzenoid Hk. In addition, the irregularities of Mycielski’s constructions of cycle and path graphs are analyzed.
TL;DR: An improved large-scale PAMAM d endrimer synthesis that is suitable to manufacture large amounts of highly pure and monodisperse dendrimers of generations G0–G5 is reported on.
Abstract: Dendrimers are promising polymers for biomedical applications; however, most dendrimer formulations have failed to move from laboratory science to upscaled products for preclinical testing or GMP p...
TL;DR: In this article, a thin, lightweight, and flexible lithium-ion battery that uses graphite papers deposited with nano-sized metallic layers as the current collector, LiFePO4 and Li4Ti5O12 as the cathode and anode materials, respectively, and a PE membrane soaked in LiPF6 as the separator is presented.
Abstract: A flexible, lightweight, and high conductivity current collector is the key element that enables fabrication of a high-performance, flexible lithium-ion battery. Here, we report a thin, lightweight, and flexible lithium-ion battery that uses graphite papers deposited with nano-sized metallic layers as the current collector, LiFePO4 and Li4Ti5O12 as the cathode and anode materials, respectively, and a PE membrane soaked in LiPF6 as the separator. Using thin, flexible graphite paper as a substrate for the current collector instead of a rigid, heavy metal foil enables us to demonstrate an ultra-thin lithium-ion battery (total thickness including encapsulation layers of less than 250 μm) that also features a light weight and high flexibility.
TL;DR: In this article, acetic acid functionalized pyridinium salt, namely 1-(carboxymethyl)pyrinium iodide {[cmpy]I}, has been applied as reusable nanostructured catalyst for green, simple and efficient p...
Abstract: In this work, acetic acid functionalized pyridinium salt, namely 1-(carboxymethyl)pyridinium iodide {[cmpy]I}, has been applied as reusable nanostructured catalyst for green, simple and efficient p...
TL;DR: The binding efficacy of anticancer drugs doxorubicin and tamoxifen with polyamidoamine (PAMAM-G4) dendrimers with PAMAM nanoparticles demonstrating their usefulness for drug delivery in cancer therapy is studied.
Abstract: The binding efficacy of anticancer drugs doxorubicin and tamoxifen with polyamidoamine (PAMAM-G4) dendrimers was studied in aqueous solution at physiological pH. The results of multiple spectroscop...
TL;DR: Carboxyl groups feature in the evolution of the spontaneous combustion of coal However, their elementary reaction pathways during coal self-heating still have not been found yet as mentioned in this paper. But they have been shown to be useful in coal selfheating.
Abstract: During coal self-heating, reactions of carboxyl groups feature in the evolution of the spontaneous combustion of coal However, their elementary reaction pathways during this process still have not
TL;DR: In this paper, a simple, economic, and green method for preparing water-soluble, nitrogen and sulfur co-doped carbon quantum dots via a one-step hydrothermal method is described.
Abstract: The article reports a simple, economic, and green method for preparing water-soluble, nitrogen and sulfur co-doped carbon quantum dots via a one-step hydrothermal method. Pomegranate juice served a...
TL;DR: In this article, three 2,9-disubstitued peropyrene derivatives were investigated, and the crystal structures, photophysical properties, and singlet fission phenomenon were investigated.
Abstract: Peropyrene is a promising candidate molecule for use in organic solar cells based on singlet fission, because it fulfills the energy matching requirement for singlet fission. We prepare three 2,9-disubstitued peropyrene derivatives and investigate their crystal structures, photophysical properties, and singlet fission phenomenon. Although each derivative shows different molecular overlap motifs in solid state, no singlet fission occurs under normal exciton density conditions due to the substantial stabilization of the first excited singlet (S1) state. In contrast, under high exciton density conditions, singlet fission from highly excited singlet (Sn) states, which is generated by singlet–singlet exciton annihilation, takes place to produce a triplet exciton. We also investigate the reverse process of singlet fission, that is, triplet–triplet annihilation, of peropyrene in solution state to explore the possibility of photon upconversion.
TL;DR: X-ray absorption near edge structure (XANES) spectroscopy was used to study a freshly prepared reference daguerreotype surface as the first step in devising improved methods for the conservation of these important historic artifacts.
Abstract: X-ray absorption near edge structure (XANES) spectroscopy was used to study a freshly prepared reference daguerreotype surface as the first step in devising improved methods for the conservation of these important historic artifacts The results are consistent with the formation of alloy image particles Inter-diffusion of gold and silver has led to the development of a silver-gold alloy; the composition varies with depth The amount of gold appeared to be elevated in the highlighted regions of the image while shadow regions have lower levels of gold on the surface The apparent increase in gold within the highlight region may be due to the larger surface area presented by an array of small image particles The mercury used to develop the daguerreian image showed no evidence of oxidation while a mercury-silver alloy was detected Sulfur based contaminants are also detected The implications of these findings are discussed
TL;DR: Using fully atomistic molecular dynamics simulation that are several hundred nanoseconds long, this work demonstrates the pH-controlled sponge action of PAMAM dendrimer, which acts as a wet sponge at varying pH levels.
Abstract: Using fully atomistic molecular dynamics simulation that are several hundred nanoseconds long, we demonstrate the pH-controlled sponge action of PAMAM dendrimer. We show how at varying pH levels, the PAMAM dendrimer acts as a wet sponge; at neutral or low pH levels, the dendrimer expands noticeably and the interior of the dendrimer opens up to host several hundreds to thousands of water molecules depending on the generation number. Increasing the pH (i.e., going from low pH to high pH) leads to the collapse of the dendrimer size, thereby expelling the inner water, which mimics the ‘sponge’ action. As the dendrimer size swells up at a neutral pH or low pH due to the electrostatic repulsion between the primary and tertiary amines that are protonated at this pH, there is dramatic increase in the available solvent accessible surface area (SASA), as well as solvent accessible volume (SAV).
TL;DR: In this paper, the adsorption and properties of three popularly studied aromatic amino acids, namely phenylalanine, tyrosine, and tryptophan, on the surface of the single-wall boron nitride nanotubes (BNNTs) have been explored with an empirical dispersion corrected density functional tight-binding method.
Abstract: In the present study, the adsorption and properties of three popularly studied aromatic amino acids, namely phenylalanine, tyrosine, and tryptophan, on the surface of the single-wall boron nitride nanotubes (BNNTs) have been explored with an empirical dispersion corrected density functional tight-binding method. A serials of armchair BNNTs (n = 4–12) and zigzag BNNTs (n = 8–18) with the aromatic amino acid adsorbed on the surface are investigated. With the dispersion correction explicitly considered in the density functional tight-binding method, the adsorption properties between amino acids and BNNTs are described by including long-range van der Waals interactions. It is found that the π–π and H–π stacking interactions are the main forces stabilizing the system. Based on the evidence of adsorption energy, charge density plots, and density of states analysis, the study concludes that the BNNT adsorbs the amino acids with no bonded interactions between the two parts. The interactions of amino with the BNNT...
TL;DR: In this article, the interaction of brannerite or zirconolite-type crystallites within the glass matrix was investigated and the local structure of these composite materials changed with changing synthesis conditions.
Abstract: Glass–ceramic composite materials are being investigated for numerous applications (i.e., textile, energy storage, nuclear waste immobilization applications, etc.) due to the chemical durability and flexibility of these materials. Borosilicate and Fe–Al–borosilicate glass–ceramic composites containing brannerite (CeTi2O6) or zirconolite (CaZrTi2O7) crystallites were synthesized at different annealing temperatures. The objective of this study was to understand the interaction of brannerite or zirconolite-type crystallites within the glass matrix and to investigate how the local structure of these composite materials changed with changing synthesis conditions. Powder X-ray diffraction (XRD) and Backscattered electron (BSE) microprobe images have been used to study how the ceramic crystallites dispersed in the glass matrix. X-ray absorption near edge spectroscopy (XANES) spectra were also collected from all glass–ceramic composite materials. Examination of Ti K-, Ce L3-, Zr K-, Si L2,3-, Fe K-, and Al L2,3-e...
TL;DR: In this article, the ozone (O3) chemisorption on the surface of pristine and nickel-decorated B12P12 was investigated by using first-principle study within the density functional theory.
Abstract: In the present study, by using first-principle study within the density functional theory (DFT), we investigated the ozone (O3) chemisorption on the surface of pristine and nickel-decorated B12P12 ...
TL;DR: In this paper, a method for the detection of an analyte at a low concentration with high sensitivity has become an important point of interest and an effort has been made to know the electrochemical be...
Abstract: Improvement of methods for the detection of an analyte at a low concentration with high sensitivity has become an important point of interest. An effort has been made to know the electrochemical be...
TL;DR: Without employing high dilution conditions, the fourfold 2+2 Perkin reaction of 1,6-pyrenylene-diglyoxylic acid with its reduction product 1, 6-py renylene-diacetic acid yields the corresponding tetr...
Abstract: Without employing high dilution conditions, the fourfold 2+2 Perkin reaction of 1,6-pyrenylene-diglyoxylic acid with its reduction product 1,6-pyrenylene-diacetic acid yields the corresponding tetr...