Chemistry Commons^™

A Kinetic Study Of Atom Transfer Radical Polymerization Of Styrene With Bis(2-Pyridyl)Ethylenedimethanimine Derivative Ligands, Hülya Arslan, Yasemi̇n Küçük, Ayfer Menteş, Meti̇n Hayri̇ Acar

Turkish Journal of Chemistry

Atom transfer radical polymerization (ATRP) of styrene was carried out with multidentate nitrogen-based ligands, namely N,N'-bis[phenyl(pyrid-2-yl)methylene] ethane-1,2-diamine (BPDA) and N,N'-bis[methyl(pyrid-2-yl)methylene] ethane-1,2-diamine (BMDA), and catalyst systems at catalyst/ligand molar ratios of 1/0.33, 1/0.5, 1/1, and 1/1.5 by using 2 different initiators, (1-bromoethyl)benzene (BEB) and ethyl-2-bromopropionate (EBP). Linear first-order kinetic plots were observed for ATRP of styrene upon using BPDA as a ligand with both initiators. Even though the linear slopes indicate that radical concentration remains constant during reactions, high molecular weights were obtained at low conversion and showed a linear relation thereafter. To investigate the molecular weight effect, reactions were also …

Optimization Of The Optical And Electrochemical Properties Of Donor-Acceptor Copolymers Through Functional Group And Side Chain Modification, Mark J. Seger

Theses and Dissertations--Chemistry

Donor-acceptor copolymers have received a great deal of attention for application as organic semiconductors, in particular as the active layers in low-cost consumer electronics. The functional groups grafted to the polymer backbones generally dictate the molecular orbital energies of the final materials as well as aid in self-assembly. Additionally, the side chains attached to these functional groups not only dictate the solubility of the final materials, but also their morphological characteristics. The bulk of the research presented in this dissertation focuses on the synthesis and structure-property relationships of polymers containing novel acceptor motifs. Chapter 2 focuses on the synthesis of …

Brust-Schiffrin Synthesis Of Catalytic Bipodal Pdpt Nanoparticles With Some Mechanistic Insights, Sangbum Han, Vara P. Sheela, Wei Cao, Balasubramanian Ramjee

Applied Research Center Publications

Brust–Schiffrin reduction of Pd and Pt precursors in the presence of resorcinarene amine surfactant led to the formation of substantially Pt rich, PdPt bimetallic nanoparticles of a V-shape or variants on the V-shape. New insights into this reaction are provided on the basis of reversed Brust–Schiffrin syntheses, DLS, UV-vis, and NMR analysis. Based on our experiments we conclude that the resorcinarene amine surfactant is part of the inverse micelle formed from TOABr and it also selectively complexes with the Pd salts prior to their reduction. Remarkably, the composition of the bipodal nanoparticles could be varied substantially by varying the reaction …

Wave Profile For Current Bearing Antiforce Waves, H. Morris, W. Childs, P. Pinkston, M. Hemmati, J. Christensen

Journal of the Arkansas Academy of Science

For fluid dynamical analysis of breakdown waves, we employ a one-dimensional, three-component (electrons, ions and neutral particles) fluid model to describe a steady-state, ionizing wave propagating counter to strong electric fields. The electron gas temperature and therefore the electron fluid pressure is assumed to be large enough to sustain the wave motion down the discharge tube. Such waves are referred to as antiforce waves. The complete set of equations describing such waves consists of the equations of conservation of mass, momentum and energy coupled with Poisson’s equation. Inclusion of current behind the wave front alters the set of electron fluid …

Microwave Assisted Synthesis Of Chloropentahaptocyclopentadienediphenylphosphinoethaneruthenium(Ii), S. Muthyala, Mark Draganjac

Journal of the Arkansas Academy of Science

No abstract provided.

Molecular Structure Of Pentahaptocyclopentadienebis (Tetrahydrothiophene) Triphenylphosphineruthenium(Ii) Triflate, Paul M. Nave, Mark Draganjac, A. W. Cordes

Journal of the Arkansas Academy of Science

No abstract provided.

Periplasmic Binding Proteins In Thermophiles: Characterization And Potential Application Of An Arginine-Binding Protein From Thermotoga Maritima: A Brief Thermo-Story, Alessio Ausili, Maria Staiano, Jonathan D. Dattelbaum, Antonio Varriale, Alessandro Capo, Sabato D'Auria

Chemistry Faculty Publications

Arginine-binding protein from the extremophile Thermotoga maritima is a 27.7 kDa protein possessing the typical two-domain structure of the periplasmic binding proteins family. The protein is characterized by a very high specificity and affinity to bind to arginine, also at high temperatures. Due to its features, this protein could be taken into account as a potential candidate for the design of a biosensor for arginine. It is important to investigate the stability of proteins when they are used for biotechnological applications. In this article, we review the structural and functional features of an arginine-binding protein from the extremophile Thermotoga maritima …

Structurally Diverse Hamigerans From The New Zealand Marine Sponge Hamigera Tarangaensis: Nmr-Directed Isolation, Structure Elucidation And Antifungal Activity, A. Jonathan Singh, Jonathan D. Dattelbaum, Jessica J. Field, Zlatka Smart, Ethan F. Woolly, Jacqueline M. Barber, Rosemary Heathcott, John H. Miller, Peter T. Northcote

Chemistry Faculty Publications

The NMR-directed investigation of the New Zealand marine sponge Hamigera tarangaensis has afforded ten new compounds of the hamigeran family, and a new 13-epi-verrucosane congener. Notably, hamigeran F (6) possesses an unusual carbon–carbon bond between C-12 and C-13, creating an unprecedented skeleton within this class. In particular, the structural features of 6, hamigeran H (10) and hamigeran J (12) imply a diterpenoid origin, which has allowed the putative biogenesis of three hamigeran carbon skeletons to be proposed based on geranyl geranyl pyrophosphate. All new hamigerans exhibited micromolar activity towards the HL-60 …

Theoretical Design Of Stable Small Aluminium-Magnesium Binary Clusters, Edison Osorio, Alejandro Vasquez, Elizabeth Florez, Fanor Mondragon, Kelling J. Donald, William Tiznado

Chemistry Faculty Publications

We explore in detail the potential energy surfaces of the Al_xMg_y (x, y = 1–4) systems as case studies to test the utility and limitations of simple rules based on electron counts and the phenomenological shell model (PSM) for bimetallic clusters. We find that it is feasible to design stable structures that are members of this set of small Al–Mg binary clusters, using simple electron count rules, including the classical 4n + 2 Hückel model, and the most recently proposed PSM. The thermodynamic stability of the title compounds has been evaluated using several different descriptors, including …

Biomaterial-Induced Osteogenesis Of Mesenchymal Stem Cells By Surface Roughness And Functionalization, Pongkwan Sitasuwan

Theses and Dissertations

For tissue engineering and regenerative medicine, it is important to understand factors directing the stem cell fate, including self-renewal, proliferation, differentiation, and apoptosis. Bone marrow derived mesenchymal stem cells (BMSCs) have the potential to differentiate into osteoblasts, chondrocytes, adipocytes, and smooth muscle cells. Specifically, in the field of bone tissue engineering, BMSCs are commonly used for in vitro osteogenesis studies. However the mechanisms and signaling pathways that these cells recognize material surface and utilize to differentiate are still unclear. This dissertation focuses on investigating the effect of surface nanotopography and functionalization on the promotion of osteogenic differentiation of BMSCs. Surface …

Renewable Bio-Based Polymers And Degradable Functional Polymers, Kejian Yao

Theses and Dissertations

In this dissertation, polymers derived from renewable bio-based resources and degradable functional polymers with stimuli-responsive properties by various polymerization techniques were investigated. The properties of these polymeric materials were characterized and discussed.

In Chapter 1, the overall background and recent development of renewable bio-based polymers as well as degradable stimuli-responsive polymers was introduced. Major research objectives of my doctoral work were described.

The first section of the dissertation, on the preparation of renewable bio-based polymers was provided from Chapter 2 to Chapter 4. In Chapter 2, the preparation of novel polymers derived from renewable gum rosin by atom transfer radical …

New Ruthenium And Osmium Carbonyl Cluster Complexes With Main Group Bridging Ligands Having Unusual Structures And Bonding, Yuwei Kan

Theses and Dissertations

The reaction of IrRu3(CO)13(µ-H), 2.1 with HSnPh3 in hexane solvent at reflux has provided the new mixed metal cluster compounds Ir2Ru2(CO)11(SnPh3)(µ-H)3, 2.2 and IrRu3(CO)11(SnPh3)3(µ-H)¬4, 2.3 containing SnPh3 ligands. Compound 2.2 which was obtained in low yield (3%) contains a closed cluster having two iridium and two ruthenium atoms, one SnPh3 ligand and three bridging hydride ligands. Compound 2.3 has a butterfly structure for the four metal atoms with three SnPh3 ligands and four bridging hydride ligands around the periphery of the cluster. When compound 2.3 was heated to 97 oC for 30min, IrRu3(CO)9(μ-η2-C6H5)(μ4-SnPh)2(μ-SnPh2), 2.4 was formed by cleavage of phenyl …

Study Of Porous, Crystalline Supramolecular Boronates, Vincenzo Michael Disantis

Theses and Dissertations

Porous materials with the ability to selectively absorb volatile organic compounds are of high interest for applications in sensing, sequestration and separations. Utilizing the covalent yet reversible boronate ester bonds between boronic acids and diols in conjunction with dative boron-nitrogen coordination bonds has allowed for the discovery of a new class of porous materials. Preliminary results show the ability to obtain porous, crystalline supramolecular boronate networks from the coordination of diamine linkers with boronate diester backbones. Further exploration of porous, crystalline supramolecular boronates has revealed the discovery of a porous crystalline coordination polymer that exhibits reversible, selective guest adsorption properties …

Study On Crystal Transformation Process Of Magnesium Carbonate Hydrate Based On Salt Lake Magnesium Resource Utilization, Juan Du, Zhen Chen, Yulong Wu, Mingde Yang, Jie Dang, Jianjun Yuan

Turkish Journal of Chemistry

The crystal transformation process of magnesium carbonate hydrate by the reaction of magnesium sulfate (MgSO_4) with ammonium carbonate [(NH_4)_2CO_3] was investigated. MgSO_4 is one of the main magnesium resources of the Lop Nur salt lake in the Xinjiang Autonomous Region of China. Magnesium carbonate hydrates with different chemical compositions were prepared. The transformation process of the 2 crystals, MgSO_4 and (NH_4)_2CO_3, was analyzed by Raman spectroscopy, and the associated changes in crystal morphology were observed by scanning electron microscopy. The needle-like MgCO_3 \cdot 3H_2O transformed into sheet-like 4MgCO_3 \cdot Mg(OH)_2 \cdot 4H_2O when the temperature was increased from 323 K …

Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi

Turkish Journal of Chemistry

Reactions of isocyanides with thioacids in water proceeded smoothly at room temperature and in neutral conditions to afford thioformylamide and thioformamide derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed.

Synthesis, Spectroscopic Characterization, And Genotoxicity Of A New Group Of Azo-Oxime Metal Chelates, Beyza Cabi̇r, Bariş Avar, Mehmet Gülcan, Ahmet Kayraldiz, Mükerrem Kurtoğlu

Turkish Journal of Chemistry

A new azo-oxime ligand, 2-[(E)-(hydroxyimino)methyl]-4-[(E)- (4-nitrophenyl)diazenyl]phenol, (pxoxH_2) (2), was prepared by condensation of hydroxylamminehydrochloride and 2-hydroxy5- [(4-nitrophenyl)diazenyl]benzaldehyde (1) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in ethanol. The 6 coordination compounds, [Mn(pxoxH)_2(H_2O)_2].H_2O (3), [Co(pxoxH)_2(H_2O)_2].4H_2O (4), [Ni(pxoxH)_2(H_2O)_2].2H_2O (5), [Cu(pxoxH)_2].H_2O (6), [Zn(pxoxH)_2].6H_2O (7), and [Cd(pxoxH)_2(H_2O)_2].H_2O (8), were prepared by reacting Mn(II), Ni(II) Cu(II), Co(II), Zn(II), and Cd(II) ions with the ligand. The structures of the compounds were elucidated from the elemental analysis data and spectroscopic studies. The azo-oxime metal complexes were also characterized by XRD, magnetic moment, molar conductivity, and thermal analyses. Elemental analyses of the chelates …

Biotinylated N,N'-Diarylureas As Probes For The Activation Of Adenosine Monophosphate-Activated Kinase (Ampk), Vitaliy Sviripa, Michael D. Conroy, Wen Zhang, Alice Liu, David S. Watt

Turkish Journal of Chemistry

Biotinylated analogs of drug candidates provide useful tools for studying the drug--target protein interactions. Polyhalogenated N,N'diarylureas are potent activators of adenosine monophosphate-activated kinase (AMPK) and potentially promising agents for the treatment of cancer. Various biotinylated versions of these N,N'-diarylureas were synthesized and evaluated in AMPK-activation studies.

An Expedient Synthesis Of 6-Vinylfulvene, İhsan Erden, Jenny Sabol, Ana Gubeladze, Andrea Ruiz

Turkish Journal of Chemistry

6-Vinylfulvenes constitute a class of fulvenes that are difficult to access due to the lack of a general method for their synthesis. In particular, the unsubstituted parent system has been very difficult to obtain by existing methods. In this communication we describe a convenient 3-step protocol for the synthesis of the title compound by way of sulfide oxidation and subsequent sulfoxide elimination.

(Nhc)-Pd(Ii) Complexes With Hydrophilic Nitrogen Ligands: Catalytic Properties In Neat Water, Hayati̇ Türkmen, Lütfi̇ye Gök, İbrahi̇m Kani̇, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

The cleavage reactions of the dimers [(NHC)PdX_2]_2 with hydrophilic N-donors, L, afforded the mixed-ligand complexes of the type trans-[(NHC)LPdX_2] (X = Cl or Br; NHC = 1,3-dialkylbenzimidazol-2-ylidene (BIm) or bis(imino)acenaphthene-annulated bis(2,6-diisopropylphenyl)imidazol-2-ylidene (BIAN-IPr); L = diethanolamine (DEA), morpholine (MOR), and 3-pyridinecarboxylic acid (3-PCA)). The new complexes (1--3) were characterized by elemental analysis and spectroscopic methods and the molecular structure of 1a was determined by X-ray diffraction studies. These complexes were applied in the Suzuki--Miyaura cross-coupling reaction of phenylboronic acid with aryl halides in neat water. The activities of catalysts were monitored by gas chromatography--flame ionization detector and nuclear magnetic resonance. Whereas …

Aerosol-Assisted Chemical Vapor Deposition Of Copper Sulfide Nanostructured Thin Film From Newly Synthesized Single-Source Precursor, Sohail Saeed, Naghmana Rashid, Khurram Shahzad Ahmad

Turkish Journal of Chemistry

The copper(II) complex of N-[ethyl(butyl)carbamothioyl]- 3,5-dinitrobenzamide (1) has been synthesized and characterized by elemental analysis, IR spectroscopy, and atmospheric pressure chemical ionization-mass spectrometry. Thermogravimetric analysis shows that complex 2 decomposes in 2 steps to form copper sulfide. The complex was used as a single-source precursor for the deposition of copper sulfide thin film by aerosol-assisted chemical vapor deposition at 350 °C. The powder X-ray diffraction pattern of thin film of the complex showed the deposition of monoclinic roxbyite Cu_7S_4 and orthorhombic anilite Cu_7S_4 phases at 350 °C with spherical crystallites. The degree of film surface roughness was determined by atomic …

Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

Palladium-catalyzed Heck coupling reactions of styrene with bromoarene derivatives are carried out under aerobic conditions in water using water-soluble N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine (EdteH_4) and ethylenediaminetetraacetic acid disodium salt (Na_2EDTA) as ligands. The effect of different bases, catalyst loading, and additives is also monitored. The olefination of bromoarenes with styrene affords the desired products in high yields. The Na_2PdCl_4-Na_2EDTA precatalyst system is also used for the preparative scale (50.0 mmol) synthesis of 4-acetyl-trans-stilbene and 4-styrylbenzaldehyde without a noticeable decrease in the activity. Recycling studies on the Na_2PdCl_4 - Na_2EDTA precatalyst system are also tested in the coupling of 4-bromoacetophenone with styrene.

Molecular Mechanism Of Diels--Alder Reaction Between (E)-3,3,3-Trichloro-1-Nitropropene And Cyclopentadiene: B3lyp/6-31g(D) Computational Study, Radomir Jasinski, Andrzej Baranski

Turkish Journal of Chemistry

Analysis of reactivity indexes supports the polar character of the reaction between (E)-3,3,3-trichloro-1-nitropropene and cyclopentadiene. This is confirmed by the analysis of electronic properties of transition complexes involved in the reaction paths using the B3LYP/6-31G(d) algorithm. The transition state's asymmetry is large, but it is insufficient to provoke a zwitterionic reaction mechanism. Attempts to find a heterocyclic intermediate 7 in the reaction path ultimately leading to 5-endo-nitro-6-exo-trichloromethylnorbornene 3 have been unsuccessful.

Syntheses, Characterization, And Antibacterial Study Of Titanium Complexes, Raj Kaushal, Nitesh Kumar, Pamita Awasthi, Kiran Nehra

Turkish Journal of Chemistry

Titanium(II) complexes of composition TiCl_2(L)_2 [where L = 2,2'-bipyridine (bipy), 4,4'-dimethyl-2,2'-bipyridine (bpMe), 4,4'-dimethoxy-2,2'-bipyridine (bpoMe), 6,6'-dimethyl-2,2'-bipyridine (dpMe), adamantylamine (ada)] were prepared by reacting titanium tetrachloride and N-containing bulky ligands in predetermined molar ratios. The complexes synthesized were characterized by different spectroscopic techniques, viz. UV-visible, FTIR, ^1H NMR, and mass spectrometry. The stoichiometry of the complexes was established by their elemental analysis (chlorine and titanium estimation). The unit cell parameters calculated by using the powder XRD tool confirm the monoclinic unit system and P lattice type for all complexes. Antibacterial screening of the ligands as well as the complexes was carried out …

Electrochemical Determination Of Sudan Iv In Food Samples By Using Graphene-Modified Glassy Carbon Electrodes, Meifeng Chen, Xinying Ma, Xia Li

Turkish Journal of Chemistry

A simple and sensitive modified electrode was fabricated with graphene via the drop-casting method and applied for the electrochemical detection of Sudan IV. Cyclic voltammetry (CV) was used to investigate the electrochemical behaviors of Sudan IV in phosphate buffer solution (PBS). The experimental conditions such as determining medium, scan rate, and accumulation time were optimized for the determination of Sudan IV. The sensor has excellent performance associated with high sensitivity, a low detection limit (6.00 \times 10^{-8} M), and a wide linear range of 2.00 \times 10^{-7} M to 8.00 \times 10^{-5} M with a correlation coefficient as follows: i_{pc} …

Determination Of Pb(Ii) In Natural Water With Dibromo-P-Methyl-Sulfonazo By The Light-Absorption Ratio Variation Approach, Jie Zhang

Turkish Journal of Chemistry

Pb ions can react sensitively with dibromo-p-methylsulfonazo (DMSA) to form a blue complex, whose absorption is maximal at 630 nm. By means of the light-absorption ratio variation approach (LARVA), the direct determination of Pb was developed in 0.3 M nitric acid and plots of \Delta A_r^{-1} vs. c_{Pb}^{-1} are linear where \Delta A_r is the light-absorption ratio variation and c_{Pb} Pb(II) concentration is between 0 and 5.0 mg/L. The limit of detection (3\sigma) of Pb(II) is only 0.02 mg/L. This method was applied to direct analysis of natural water with satisfactory results.

Synthesis, Characterization, And Biological Activity Of Coordination Polymers Derived From Pyromellitic Dianhydride, Yogesh Patel, Ritu Dixit, Hasmukh Shanubhai Patel

Turkish Journal of Chemistry

A new ligand, 2,5-bis(furan-2-ylmethylcarbamoyl)terephthalic acid (BFMTA), was synthesized using 1,2,4,5-benzenetetracarboxylic dianhydride (pyromellitic dianhydride-PMDA) with furan-2-ylmethanamine (2-furfurylamine). New coordination polymers of the ligand (BFMTA) were also prepared using transition metal ions Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) metal salts. The coordination polymers and ligand were characterized by physico-chemical characteristics, magnetic susceptibilities, spectroscopic investigations, and thermogravimetry. Antimicrobial activity was tested using the agar-plate method against various strains of bacteria and spores of fungi. The results showed significantly higher antimicrobial activity of coordination polymers compared to the ligand.

Advances In The Chemistry Of Pyrazolopyrazoles, Rizk Elsyad Khidre, Hanan Ahmed Mohamed, Bakr Fathy Abdelwahab

Turkish Journal of Chemistry

Published data on the methods of preparation of pyrazolopyrazoles are summarized and described systematically. The title compounds are subdivided according to the position of fusion between the 2 pyrazole rings.

A New Method For Calculating The Vibration-Rotation-Tunneling Spectra Of Molecular Clusters And Its Application To The Water Dimer, Mahi̇r Erteki̇n Ocak

Turkish Journal of Chemistry

A new method is developed for calculating the vibration-rotation-tunneling spectra of molecular clusters consisting of rigid monomers. The method is based on generation of optimized bases for each monomer. First, a sequential symmetry adaptation procedure is developed for relating the symmetries of monomer basis functions with the symmetries of the eigenstates of the cluster. Then this symmetry adaptation procedure is used in the generation of optimized bases and combining them for finding the eigenstates. Symmetry adaptation problems related to the generation of optimized bases are identified and solutions are suggested. The method is applied to the water dimer by using …

Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Complexes Derived From Novel Phenolic Mannich Bases, Nurgün Büyükkidan, Sali̇h Özer

Turkish Journal of Chemistry

The novel phenolic Mannich bases 2,2'-(2-hydroxy-4,5- dimethylbenzylazanediyl)diethanol (1) and 2-((2-(4-(2-hydroxy-4,5- dimethylbenzyl)piperazin-1-yl)ethylamino)methyl)-4,5-dimethylphenol (2) have been synthesized in good yield by using a microwave-induced technique from 3,4-dimethylphenol and corresponding amines in the presence of formaldehyde. Metal complexes of 1 and 2 for Ni(II) (3 and 5) and for Cu(II) (4 and 6) have also been prepared and all compounds have been characterized by elemental and spectral analyses. Thermal, magnetic, and electronic studies have also been reported for metal complexes. Electronic spectra and magnetic susceptibility measurements suggested tetrahedral geometry for Ni(II) (3), square planar geometry for Cu(II) (4) complexes of 1, and octahedral …

New Secondary Metabolites From Croton Sparsiflorus Morong, Rashad Mehmood, Amna Bibi, Abdul Malik

Turkish Journal of Chemistry

Sparsifloamide (1), a new sphingolipid, and sparsifloside (2), a new diglyceride galactoside, have been isolated from the ethyl acetate soluble fraction of the 80% ethanolic extract of the whole plant of Croton sparsiflorus Morong. Their structures were assigned by ^1H- and ^{13}C-NMR spectra and DEPT, COSY, NOESY, HMQC, HMBC, and ESI-MS experiments.