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Plasmon-Enhanced Optical Sensing By Engineering Metallic Nanostructures, Peng Zheng

Graduate Theses, Dissertations, and Problem Reports (ETD)

The world’s booming population projected to reach 10 billion by 2050 causes enormous stresses on environmental safety, food supply, and healthcare, which in return threatens human civilizations. One of the most promising solutions lies at innovating point-of-care (POC) sensing technologies to conduct detection of environmental hazards, monitoring of food safety, and early diagnosis of diseases in a timely and accurate manner. The discovery of surface-enhanced spectroscopy in the 1970s has significantly stimulated research on light-matter interaction which gives rise to enhanced optical phenomena such as surface-enhanced Raman scattering (SERS), plasmon-enhanced fluorescence (PEF), and particularly, they have found enormous applications in …

Study Of Förster Resonance Energy Transfer To Lipid Domain Markers Ascertains Partitioning Of Semisynthetic Lipidated N-Ras In Lipid Raft Nanodomains, Anna K. Shishina, Elizaveta A. Kovrigina, Azamat R. Galiakhmetov, Rajendra Rathore, Evgenii L. Kovrigin

Chemistry Faculty Research and Publications

Cellular membranes are heterogeneous planar lipid bilayers displaying lateral phase separation with the nanometer-scale liquid-ordered phase (also known as “lipid rafts”) surrounded by the liquid-disordered phase. Many membrane-associated proteins were found to permanently integrate into the lipid rafts, which is critical for their biological function. Isoforms H and N of Ras GTPase possess a unique ability to switch their lipid domain preference depending on the type of bound guanine nucleotide (GDP or GTP). This behavior, however, has never been demonstrated in vitro in model bilayers with recombinant proteins and therefore has been attributed to the action of binding of Ras …

Structural Evidence Of A Major Conformational Change Triggered By Substrate Binding In Dape Enzymes: Impact On The Catalytic Mechanism, Boguslaw P. Nocek, Cory Reidl, Anna Starus, Tahirah Heath, David L. Bienvenue, Jerzy Osipiuk, Robert Jedrzejczak, Andzrej Joachimiak, Daniel P. Becker, Richard C. Holz

Chemistry Faculty Research and Publications

The X-ray crystal structure of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase from Haemophilus influenzae (HiDapE) bound by the products of hydrolysis, succinic acid and l,l-DAP, was determined at 1.95 Å. Surprisingly, the structure bound to the products revealed that HiDapE undergoes a significant conformational change in which the catalytic domain rotates ∼50° and shifts ∼10.1 Å (as measured at the position of the Zn atoms) relative to the dimerization domain. This heretofore unobserved closed conformation revealed significant movements within the catalytic domain compared to that of wild-type HiDapE, which results in effectively closing off access to …

Iron Transport Machinery: A Potential Therapeutic Target In Escherichia Coli, Clorissa L. Washington – Hughes

Theses and Dissertations

Iron metabolism is an integral part of life for most organisms. Despite its essentiality, iron can also become toxic. There are many aspects to maintaining iron balance within the cell. The aim of this work is to provide insight into the function of several components involved in bacterial iron homeostasis. This work is significant for the development of novel antibiotics for treating resistant or pathogenic bacteria. Herein, it is shown that nickel can disrupt normal bacterial iron metabolism and that bacterial resistance can be affected by expression of iron acquisition genes. Once iron is obtained by the cell, it can …

Designed Polymer Brush Interfaces For Plutonium Separations And Polyethylene Nanocomposites, Julia G. Pribyl

Theses and Dissertations

Modification of surfaces with polymer brushes has become an important area of research for developing materials with a variety of advanced properties. Flat or continuous surfaces modified with polymer brushes can serve as surfaces where chemical reactions or separations take place, and discrete nanoparticles covered in a polymer brush can disperse within a miscible surrounding polymer, generating a composite which retains the processability of the polymer but becomes endowed with the properties of the filler as well. Presented herein are new synthetic approaches to modify both continuous surfaces as well as discrete particles with polymer brushes for complex applications. In …

Tailoring Polybenzimidazole Membranes For Enhanced Performance In Electrochemical Devices, Andrew T. Pingitore

Theses and Dissertations

After approximately 15 years of development, polybenzimidazole (PBI) chemistries and the concomitant manufacturing processes have evolved into commercially produced membrane electrode assemblies (MEAs). PBI MEAs can operate reliably without complex water humidification hardware and are able to run at elevated temperatures of 120-180 OC due to the physical and chemical robustness of PBI membranes. These higher temperatures improve the electrode kinetics and conductivity of the MEAs, simplify the water and thermal management of the systems, and significantly increase their tolerance to fuel impurities. Membranes cast by a newly developed polyphosphoric acid (PPA) Process possessed excellent mechanical properties, higher phosphoric acid …

Synthesis And Characterization Of Polydiene-Grafted Nanoparticles, Zaid Mohammed Abbas Alajeeli

Theses and Dissertations

This dissertation presents the design, synthesis, and characterization of polydiene grafted nanoparticles as a way to tailor nanocomposite interfaces and properties via interface design. The polymerization of dienes was done via reversible addition fragmentation chain transfer (RAFT) polymerization. The grafting of polymer chains on the surface of silica nanoparticles can be controlled through the molecular design of the RAFT agents attached to the nanoparticles surface. The properties of the nanocomposites largely depended on the interface between the particles and the polymer matrix. In the first part of this work, the polymerization of diene monomers was done on 15 nm diameter …

Development Of A High-Resolution Spatial Heterodyne Libs Spectrometer, Kevin A. Dudley

Theses and Dissertations

Laser-Induced Breakdown Spectroscopy (LIBS) is an atomic emission technique that uses a pulse laser to ablate a sample and form a plasma. Atomic emissions from the plasma provide unique elemental characteristics regarding the composition of the sample. The technique produces valuable qualitative results, but the accuracy of quantitative analyses is hindered by spectral line broadening mechanisms and laser pulse reproducibility, among other factors. The Spatial Heterodyne Spectrometer (SHS) is a high-resolution spectrometer with very high light throughput, and its use to LIBS is currently limited to two peer-reviewed publications. In the following work a high resolution SHS is developed and …

A Comparison Of On-Line And Off-Line Bioaerosol Measurements At A Biowaste Site, Patrick Feeney, Santiago Fernández Rodríguez, Rafael Molina, Eoin Mcgillicuddy, Stig Hellebust, Michael Quirke, Shane Daly, David O'Connor, John Sodeau

Articles

An air measurement campaign was carried out at a green-waste composting site in the South of Ireland during Spring 2016. The aim was to quantify and identify the levels of Primary Biological Aerosol Particles (PBAP) that were present using the traditional off-line, impaction/optical microscopy method alongside an on-line, spectroscopic approach termed WIBS (Wideband Integrated Bioaerosol Sensor), which can provide number concentrations, sizes and “shapes” of airborne PBAP in real-time by use of Light Induced Fluorescence (LIF). The results from the two techniques were compared in order to validate the use of the spectroscopic method for determining the releases of the …

Protection Of Triplet Excited State Materials From Oxygen Quenching And Photooxidation In Optical Sensing Applications, Mikhail Filatov

Books/Book chapters

No abstract provided.

Syntheses Of Azepinoindole Alkaloids Cimitrypazepine, Fargesine And Hyrtioreticulins C & D, Ganesh Ghimire

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Watanabe-Cenini-Söderberg reductive N-heterocyclization has emerged as a powerful tool for the synthesis of a variety of functionalized indoles. Söderberg’s elaboration of this methodology has been utilized as a late-stage cyclization protocol for the synthesis of azepinoindole alkaloids, a class of natural products characterized by an azepane skeleton fused with an indole ring. Short syntheses of the naturally occurring azepino[5,4,3-cd]indole alkaloids, cimitrypazepine, fargesine, and the diastereomeric hyrtioreticulins C & D have been completed starting from commercially available tetra-substituted benzene derivatives. The key azepinoindole core in each case was assembled via an intramolecular Mizoroki-Heck reaction followed by a …

Chemistry Goes Green - Experimental Determination Of Pka Values And Metal Binding For Biomolecular Compounds Using 31p Nmr Spectroscopy, R.A. Baker, C.D. Tatko, P.J. Tubergen, M.A. Swartz

University Faculty Publications and Creative Works

1. Research was conducted at UNC-CH for the spring/summer semesters of 2015
2. The following publications were obtained using methods and data from the sabbatical period, though not on the anticipated timeline

Swartz, M.A.*; Tubergen, P.J.*; Tatko, C.D.; Baker, R.A. (2018) “Experimental Determination of pKa Values and Metal Binding for Biomolecular Compounds Using 31P NMR Spectroscopy” Journal of Chemical Education, 95, 1, 182-185.

The proposed work was the bulk of all time used during the sabbatical period. However, this particular research program proved to be extraordinarily complicated. Sophisticated technology was required to support this work that is not available at …

Hybrid Organic Molecules As Antiinammatory Agents; A Review Of Structuralfeatures And Biological Activity, Noor Ul Amin Mohsin, Matloob Ahmad

Turkish Journal of Chemistry

Nonsteroidal antiin ammatory drugs (NSAIDs) are widely used for the treatment of pain and in ammation. Some undesirable effects are linked with NSAIDs such as the gastrointestinal tract (GIT) toxicity and cardiovascular disturbances. At present the preparation of a hybrid molecular technique is being used to produce new analgesic and antiin ammatory molecules. Attachment of NSAIDs with nitric oxide and hydrogen sulfide releasing molecules produced some gastroprotective agents with improved analgesic and antiinflammatory activities. Combination of NSAIDs with different biologically active 5-membered, 6-membered, and condensed heterocyclic rings has also led to the formation of some potent molecules. Some of these …

Facile Synthesis Of Heteroaryl Substituted -Lactams From Nitrovinyl Arenes, Seda Çinar, Canan Ünaleroğlu

Turkish Journal of Chemistry

Aliphatic nitroalkanes with different functional groups were synthesized from the Michael addition reactions of active methylene compounds 2 and nitrovinyl arenes 1 in high yields. The synthesized Michael adducts were subjected to intramolecular cyclization to give heteroaryl substituted γ-lactams in good to high yields under mild reaction conditions.

Biological Study On Novel Coumarinyl 1,3,4-Oxadiazoles, Maja Molnar, Ana Amic, Valentina Pavic, Tihomir Kovac, Marija Kovac, Elizabeta Has-Schön

Turkish Journal of Chemistry

Coumarinyl 1,3,4-oxadiazoles were synthesized from Schiff bases and acetic anhydride. All compounds were characterized by melting points and their structures confirmed by mass and $^{1}$H and $^{13}$C NMR spectrometry. These novel coumarinyl derivatives were subjected to antibacterial, antifungal, anta atoxigenic, and antioxidant activity. Their activity varied depending on their structure, where 2-(3-acetyl-5-(((4-methyl-2-oxo-2H-chromen-7-yl)oxy)methyl)- 2,3-dihydro-1,3,4-oxadiazol-2-yl)-1,4-phenylene diacetate showed significant antioxidant and antibacterial activity on B. subtilis. 4-(3-Acetyl-5-(((4-methyl-2-oxo-2H-chromen-7-yl)oxy)methyl)-2,3-dihydro-1,3,4-oxadiazol-2-yl)-1,2-phenylene diacetate was found to possess excellent antifungal and antia atoxigenic activity.

Cu(Ii) Immobilized On Fe$_{3}$O$_{4}$ @Agarose Nanomagnetic Catalyst Functionalizedwith Ethanolamine Phosphate-Salicylaldehyde Schiff Base: A Magnetically Reusablenanocatalyst For Preparation Of 2-Substituted Imidazolines, Oxazolines, Andthiazolines, Zeinab Zarei, Batool Akhlaghinia

Turkish Journal of Chemistry

Herein we synthesized Cu(II) immobilized on Fe$_{3}$O$_{4}$ @Agarose functionalized with ethanolamine phosphate{ salicylaldehyde Schiff base (Fe$_{3}$O$_{4}$ @Agarose/SAEPH$_{2}$ /Cu(II)) as a new and cost-effective nanomagnetic catalyst. The nanomagnetic catalyst was characterized by FT-IR, XRD, VSM, SEM-EDX, TEM, TGA, and ICP techniques and it was found that the particles were about 9-25 nm in size and spherical with entrapment of the Fe$_{3}$O$_{4}$ particles in the hollow pore structure of the agarose. The prepared nanomagnetic catalyst showed excellent activity for preparation of 2-substituted imidazolines, oxazolines, and thiazolines. The catalyst is easy to prepare and exhibits higher catalytic activity than some commercially available copper …

Tetrahydronaphthalene As A Precursor Of New Series Of Chalcones, Flavanones, And Flavones, Ahmed Meddeb, Ghalia Bouhalleb, Julien Legros, Farhat Rezgui

Turkish Journal of Chemistry

An efficient synthetic route for a novel series of chalcones 2a-2d as well as for the corresponding flavanones 3a-3d and flavones 4a-4d, using functionalized tetrahydronaphthalene (THN), is described herein. The Claisen-Schmidt condensation of such THN and aromatic aldehydes, in the presence of an aqueous solution of KOH (40%), selectively gives the expected chalcones 2a-2d, which may further undergo an intramolecular oxa-Michael addition using piperidine, affording the corresponding flavanones 3a-3d in high yields. Alternatively, treatment of such chalcones 2a-2d with I$_{2}$/DMSO provides rapidly, in a one-pot oxidative cyclization, a series of flavones 4a-4d in excellent yields ranging from 85% to 90%.

Spectroscopic And Thermodynamic Approach To The Interaction Of Nonperipherally Substituted Cationic Phthalocyanines With Calf Thymus (Ct)-Dna, Sevgi̇can Tuncer, İbrahi̇m Özçeşmeci̇, Behi̇ce Şebnem Sesalan, Ayfer Kalkan Burat

Turkish Journal of Chemistry

Novel, nonperipherally tetrasubstituted cationic metal-free and metallophthalocyanines (Zn, In) were synthesized in the present study. The binding constants, the disappearance of quenching effect of all cationic phthalocyanines on the fluorescence intensity of SYBR Green--disodium salt of deoxyribonucleic acid (DNA) from calf thymus complex, and the changes in T$_{m}$ of double helix DNA with thermal denaturation profile were investigated by UV-Vis and fluorescence spectrophotometric methods. To investigate the spontaneity of the reactions between DNA and novel quaternized phthalocyanines in buffer, thermodynamic parameters were employed.

Peg-Peptide Conjugate Containing Cathepsin B Degradation Unit As A Doxorubicin Carrier System, Nesli̇gül Şentürk, Ayben Top

Turkish Journal of Chemistry

A drug delivery system (DDS) containing a cathepsin B degradable sequence and pH-responsive histidines was prepared by methoxypolyethylene glycol and peptide conjugation. Doxorubicin was attached to the carrier system using amide linkage to give the final form of the DDS, denoted as mPEG-AT3-DOX. mPEG-AT3-DOX exhibited a bimodal size distribution at about 15 and 30 nm independent of pH, whereas the size of the control DDS containing no peptide sequence, mPEG-DOX, was measured as $\sim$ 15-20 nm. At the end of 72 h, % doxorubicin release from both of the DDSs was observed to be below 8.5 $\pm$ 3% in the …

Synthesis And Biological Evaluation Of Novel Chalcones Bearing Morpholine Moiety As Antiproliferative Agents, Bedri̇ye Seda Kurşun Aktar, Emi̇ne Elçi̇n Oruç-Emre, İbrahi̇m Demi̇rtaş, Ayşe Şahi̇n Yağlioğlu, Ayşegül Karaküçük İyi̇doğan, Çağlar Güler, Şevki̇ Adem

Turkish Journal of Chemistry

In this research, a new series of ($E)$-3-(4-substitutedphenyl)-1-(4'-morpholinophenyl)prop-2-en-1-one derivatives 1-7 was synthesized, aiming to develop effective antiproliferative agents. The antiproliferative activities of compounds 1-7 were examined against HeLa and C6 cell lines at eight different concentrations using the BrdU ELISA assay. The activity results were compared with reference anticancer drug 5-fluorouracil (5-FU). Compound 1 had almost the same antiproliferative activity as 5-FU. Compounds 1-7 were found to have greater effects against the C6 cell line than the HeLa cell line. These compounds were also tested in order to determine their effects on enzyme activities. Compounds 2 and 3 exhibited strong …

A Novel Hypobromous Acid Scavenging Activity Assay Using $P$-Cresol As A Spectrofluorometric Probe, Burcu Bekdeşer, Gülüzar Zeytünlü, Mustafa Özyürek, Mustafa Reşat Apak

Turkish Journal of Chemistry

In this study, a novel spectrofluorometric assay based on $p$-cresol (4-methyl phenol) probe is developed for the measurement of HOBr scavenging activity. It is the first study involving the use of a $p$-cresol probe for the determination of the HOBr scavenging activity of biothiols. While the $p$-cresol probe ($\lambda_{ex}$ = 260 nm, $\lambda_{em}$ = 305 nm) has fluorescence characteristics, its brominated derivatives emerging at the end of the oxidation reaction with HOBr do not show fluorescence. The initial fluorescence intensity of the $p$-cresol probe is decreased in the presence of the brominating agent, HOBr, and this decrease is lower in …

$S$-Substituted Derivatives Of 1,2,4-Triazol-3-Thiol As New Drug Candidates For Type Ii Diabetes, Aziz Ur Rehman, Khadija Nafeesa, Muhammad Athar Abbasi, Sabahat Zahra Saddiqui, Shahid Rasool, Syed Adnan Ali Shah, Muhammad Ashraf, Muhammad Arif Lodhi, Farman Ali Khan, Bakht Jahan

Turkish Journal of Chemistry

The therapeutic applications of 1,2,4-triazoles motivated us to synthesize some new derivatives. Two series of $S$-substituted derivatives (8a-8j, 12a-12i) of 5-$\{$1-[(4-chlorophenyl)sulfonyl]-3-piperidinyl$\}$-4-phenyl-4$H$-1,2,4-triazol-3-thiol (6) have been synthesized and evaluated for their biological potential. Using 4-chlorobenzene sulfonyl chloride (1) and ethyl piperidine-3-carboxylate (2), ethyl 1-[(4-chlorophenyl)sulfonyl]piperidine-3-carboxylate (3) was synthesized and converted into 3,4,5-trisubstituted 1,2,4-triazole (6) through formation of the corresponding carbohydrazide (4) and hydrazinecarbothioamide (5). Compound 6 was transformed into 8a-8j by alkyl halides (7a-7j) and into 12a-12i by $N$-aralkyl/aryl-2-bromoacetamides (11a-11i) in an aprotic solvent. The electrophiles, 11a-11i, were synthesized by gearing up $N$-substituted aralkyl/aryl amines (10a-10i) with 2-bromoacetyl bromide (9) under dynamic pH …

One-Pot Multicomponent Synthesis Of Piperidinium 3,3'-(Arylmethylene) Bis (2-Hydroxynaphthalene-1,4-Diones): Nmr Spectroscopic And X-Ray~Structure Characterization, Maryam Fatahpour, Nourollah Hazeri, Malek Taher Maghsoodlou, Fatemeh Noori Sadeh, Mojtaba Lshkari

Turkish Journal of Chemistry

A facile synthesis of piperidinium 3,3'-(arylmethylene) bis (2-hydroxynaphthalene-1,4-dione) analogs as organic salts is described by the one-pot pseudo-four-component reaction between 2-hydroxy-1,4-naphthoquinone, aromatic aldehydes, and piperidine. The single-crystal X-ray diffraction analysis of these systems confirms that the stabilized predominant interactions are N-H\... O and O-H\... O hydrogen bonds. Mild and clean reaction conditions, high atom economy, and operational simplicity of this one-pot multicomponent reaction coupled with excellent yields and no need for column chromatography have transformed this procedure to be a superior synthetic route for the efficient formation of families of naphthoquinone-derived compounds.

Physicochemical Characterization Of Different Cellulose Polymorphs/Graphene Oxide Composites And Their Antibacterial Activity, Sherif Mohamed Abdel Salam Keshk, Ibrahim Sayed Yahia

Turkish Journal of Chemistry

In order to investigate the interaction of graphene oxide (GO) with different cellulose polymorphs (I and II), we synthesized cellulose (I and II)/GO composites using the sonication method. Interestingly, no new peaks were observed in the FT-IR pattern of the cellulose (I and II)/GO composites, indicating that no chemical reactions took place between GO and cellulose. The X-ray diffraction patterns of cellulose I and II/GO composites were slightly different than those observed for cellulose I and II, indicating that some physical interactions occurred between the GO and cellulose. Unexpectedly the $d$-spacing values and the diffraction plane at the high-angle side …

Environmental Impact Assessment Of Natural Radioactivity And Heavy Metals In Drinking Water Around Akkuyu Nuclear Power Plant In Mersin Province, Gürsel Karahan, Hali̇m Taşkin, Nesli̇ Bi̇ngöldağ, Eni̇s Kapdan, Yusuf Zi̇ya Yilmaz

Turkish Journal of Chemistry

The aim of this study was to determine natural radioactive and heavy element concentrations in Mersin drinking water samples before the commissioning of the Akkuyu nuclear power plant and to collect data for possible environmental contaminations in the future. Drinking water samples were taken from the provincial center, districts, and populated villages. The annual effective dose of natural radionuclides and cancer risks were calculated for each person living in the city. Hazard index and cancer risk were calculated, which were caused by heavy elements. Mean gross alpha and beta radioactivity concentrations in drinking water were 0.059 Bq/L and 0.120 Bq/L, …

Synthesis Of Novel Sn38-Aspirin Prodrugs For The Treatment Of Hepatocellular Carcinoma, Zhimin Chen, Yi Luo, Aiping Fang, Chen Fan, Chenjuan Zeng

Turkish Journal of Chemistry

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is a leading cause of cancer-related death worldwide. However, there is no effective chemotherapeutic treatment for HCC and its prognosis remains poor. Consequently, it is urgent to find an efficient antitumor agent to treat HCC. In this study, 7-ethyl-10-hydroxycamptothecin (SN38), the bioactive metabolite of the anticancer drug irinotecan (CPT-11), which is 100-1000 times more potent than CPT-11, was coupled with aspirin to give 4 prodrugs. Their structures were characterized by $^{1}$H~NMR and elemental analysis. The in vitro anticancer activities of these compounds on two human hepatocellular carcinoma cell lines …

New $N$-4 Piperazinyl Derivatives Of Norfloxacin: Design, Synthesis, And Correlation Of Calculated Physicochemical Parameters With Antibacterial Activity, Gamal El-Din Abou Rahma, Samar Abbas, Mai Shoman, Ibtihal Samir, Rehab Abd El-Baky

Turkish Journal of Chemistry

A group of $N-$4 piperazinyl derivatives of norfloxacin was synthesized and identified by different spectroscopic techniques. The $N-$4 piperazinyl substituent in target compounds 2a-2k, 3a-3c, and 4a and 4b was designed to have different electronic, steric, and physicochemical properties. The antibacterial activity of the newly synthesized compounds was evaluated against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus strains using norfloxacin as a reference. Results showed that most of the tested compounds had higher activity against E. coli and K. pneumoniae than norfloxacin, whereas only five derivatives were more active against P. aeruginosa. On the other hand, all derivatives …

Synthesis, Characterization, And Evaluation Of Antioxidant Activity Of New $\Gamma $- And $\Delta $-Imino Esters, Hasni̇ye Yaşa

Turkish Journal of Chemistry

New Schiff bases were synthesized by condensation of methyl-5-(furan-2-yl)-5-oxopentanoate, methyl-4-(furan-2-yl)-4-oxobutanoate, methyl-5-(thiophene-2-yl)-5-oxopentanoate, and methyl-4-(thiophene-2-yl)-4-oxobutanoate with $p$-anisidine and $n$-butylamine. The structures of these synthesized compounds were clarified on the basis of elemental analysis, IR, $^{1}$H NMR, $^{13}$C NMR, and GC-MS spectroscopic techniques. In addition, antioxidant activity of the synthesized compounds was evaluated on the basis of DPPH radical.

Synthesis, Characterization, And Evaluation Of Toxicity Of Quaternary Ammonium Chlorides Of Glucose-Based Este, Anna Parus, Grzegorz Framski

Turkish Journal of Chemistry

This study presents the synthesis of glucose-based surfactants including quaternary ammonium salts. Their surface properties and influence on the soil environment were investigated. The synthesized quaternary ammonium chlorides of glucose-based ester exhibited good surface tension reduction properties and formed stable foam in contact with water. The results showed that quaternary ester ammonium salts affect the activation of metals (nickel and cadmium) from the soil matrix after their introduction into the soil environment. This phenomenon can increase the bioavailability of these metals. The introduction of glucose surfactants to the soil increased microorganism activity, which may indicate that these compounds were used …

Syntheses And Characterizations Of Cyclotriphosphazenes Containing A 4-Oxy-1-Naphthaldehyde Group, Hani̇fe İbi̇şoğlu, Esra Tanriverdi̇ Eçi̇k, Gönül Yeni̇lmez Çi̇ftçi̇

Turkish Journal of Chemistry

The nucleophilic substitution reaction of hexachlorocyclotriphosphazene (N$_{3}$P$_{3}$Cl$_{6}$, trimer) (1) with 4-hydroxy-1-naphthaldehyde (2) has been investigated for the first time. 4$^{{\prime}} $-Oxy-1$^{{\prime}} $-naphthaldehyde substituted mono- (3), bis- (4), and tris- (5) cyclotriphosphazenes were obtained from the nucleophilic substitution of compound 1 with 2 in a 1:2 molar ratio in the presence of Cs$_{2}$CO$_{3}$ in acetone at reflux. The pentakis-(6) and hexakis-substituted (7) cyclotriphosphazenes were prepared from the reaction of 1 with 2 in a 1:7 molar ratio using K$_{2}$CO$_{3}$ as a proton abstractor in tetrahydrofuran at room temperature. The structures of the new compounds (3-7) were determined by elemental analysis, FT-IR, …