Physical Sciences and Mathematics Commons^™

Tpm^Ph Derivative Of Tungsten; Hydrogen-Bonding In 7-Coordinate Cation Complex, Olivia Ryon Simcox

Undergraduate Honors Thesis Collection

Tpm^Ph, or tris(3-phenylpyrazolyl)methane reacts with tungsten hexacarbonyl to form the ligand-metal complex tris(3-phenylpyrazolyl)methane tungsten tricarbonyl, or Tpm^PhW(CO)3. The further complexes of Tpm^PhW(CO)3 and Tpm^PhMo(CO)3 are not known. This project aims to explore how the addition of a phenyl substituent to the pyrazole ring on Tpm impacts the synthesis of [Tpm^PhW(CO)3I]+X– and [Tpm^PhW(CO)3H]+X–. The inclusion of this phenyl substituent may impact the possible hydrogen bonding of then hydrogen contained in the carbon-hydrogen bond. This work aims to explore the extent of hydrogen-bonding of the carbon-hydrogen bond of the Tpm^Ph ligand in cationic metal complexes.

Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes, Roberto M. Escobar, Abdurrahman C. Ateşin, Christian Müller, William D. Jones, Tülay Ateşin

Research Symposium

Carbon–carbon (C–C) bond activation has gained increased attention as a direct method for the synthesis of pharmaceuticals. Due to the thermodynamic stability and kinetic inaccessibility of the C–C bonds, however, activation of C–C bonds by homogeneous transition-metal catalysts under mild homogeneous conditions is still a challenge. Most of the systems in which the activation occurs either have aromatization or relief of ring strain as the primary driving force. The activation of unstrained C–C bonds of phosphaalkynes does not have this advantage. This study employs Density Functional Theory (DFT) calculations to elucidate Pt(0)-mediated C–CP bond activation mechanisms in phosphaalkynes. Investigating the …

Alkylthiocarbamate Metal Complexes With Antiproliferation Activity., Kritika Bajaj

Electronic Theses and Dissertations

Bis(thiosemicarbazones) (BTSCs) and their metal complexes have been extensively studied for various applications including catalysis for hydrogen evolution reactions, treatment of neurodegenerative diseases, hypoxia imaging, and a wide range of pharmacological purposes including antitumor, antiviral, antibacterial, and antifungal agents. The paramount property that makes BTSC metal complexes interesting for their use in these applications is the reduction potential of the coordinated metal, which can be selectively tuned by varying the substituents present on the ligand framework. Although the BTSCs have shown a great deal of success as potential cancer therapeutic agents, they lack selectivity towards cancer cells. For this matter, …

Synthesis Of Carborane Pincer Complexes And Exploration Of The Reactivity Of Metal-Boron Bonds, Hindurangalage Don Asela Chathumal Jayaweera

Theses and Dissertations

Exploration of transition metal complexes with metal-boron bonds for the cooperative bond activation of small molecules in catalysis is one of the recent developments in novel synthetic strategies. The use of boron clusters as a modular platform for the formation of metal-boron bond has been successfully utilized by our and other groups. Carboranes are icosahedral boron-carbon molecular clusters that have gained attraction as multifunctional ligands due to their unique geometry, electronic properties, and versatility of functionalization methods. Their 3-D structure exerts a steric bulk around the exohedral substituent, either metal or non-metal center. Furthermore, due to the cluster geometry, five …

Metal Complexes Of Bis(Pyrazolyl)Methane-Based Ditopic Ligands, Pubudu Nuwan Perera Hapuarachchige

Masters Theses

No abstract provided.

Synthesis And Characterization Of Starburst Pseudorotaxanes And Their Metallic Derivatives, Shalini D. Kadinappulige

Masters Theses

Mechanically Interlocked Molecules (MIMs) are interlocked molecular architectures, characterized by the fact that they are linked through a mechanical bond. Catenanes, rotaxanes, molecular knots, and Borromean rings are typical examples for these molecules. Since MIMs are not connected by covalent bonds, hydrogen bonding, π- π stacking, and/or electrostatic interactions help bring the components together. Dialkyl-ammonium centers, bis(pyridinium)ethane dications, viologen species, and naphthalenediimide π-deficient groups are well known as recognition motifs for crown ethers. In the research described here, we have synthesized several pseudorotaxanes and their tricyclohexyltin metallic derivatives, based on benzobis(imidazolium) (BBI) salts as axles, in combination with the 15DN38C10 …

Bimetallic Complexes: The Fundamental Aspects Of Metal-Metal Interactions, Ligand Sterics And Application, Michael Bernard Pastor

University of the Pacific Theses and Dissertations

Metal containing complexes have been used to catalyze various organic transformations for the past few decades. The success of several mononuclear catalysts led to transition metal catalysts used in pharmaceuticals, environmental, and industrial processes. While mononuclear complexes have been used extensively, bimetallic systems have received far less attention. Bimetallic or polynuclear sites are commonly found in metalloenzymes that perform elegant transformation in biological systems, underlying their significance. Inorganic chemists take inspiration from nature and design model bimetallic complexes to further study this cooperativity effect. A bimetallic platform offers many structural and functional differences such as the identity of the metal …

The Antibacterial Activity Of Metal Complexes Containing 1, 10-Phenanthroline: Potential As Alternatire Therapeutics In The Era Of Antibiotic Resistance, Livia Viganon, Orla L. Howe, Pauraic Mccarron, Malachy Mccann, Michael Devereux

Articles

The “antibiotic era”, characterized by the overuse and misuse of antibiotics, over the last half-century has culminated in the present critical “era of resistance”. The treatment of bacterial infections is challenging because of a decline in the current arsenal of useful antibiotics and the slow rate of new drug development. The discovery of a new gene (mcr-1) in 2015, which enables bacteria to be highly resistant to polymyxins (such as colistin), the last line of antibiotic defence left, heralds a new level of concern as this gene is susceptible to horizontal gene transfer, with alarming potential to be spread between …

Homo- And Heterometallic Bis(Pentafluorobenzoyl)Methanide Complexes Of Copper(Ii) And Cobalt(Ii), Janell Crowder

Legacy Theses & Dissertations (2009 - 2024)

β-Diketones are well known to form metal complexes with practically every known metal and metalloid. Metal complexes of fluorinated β-diketones generally exhibit increased volatility and thermal stability compared to the non-fluorinated analogues, and thus are used extensively in various chemical vapor deposition (CVD) processes for the deposition of metal, simple or mixed metal oxides, and fluorine-doped metal oxide thin films. Furthermore, the electron-withdrawing nature of the fluorinated ligand enhances the Lewis acidity of a coordinatively unsaturated metal center which facilitates additional coordination reactions. The physical and structural properties of fluorinated β-diketonate complexes are discussed in Chapter 1 …

A Novel Copper (Ii) Complex Identified As A Potent Drug Against Colorectal And Breast Cancer Cells And As A Poison Inhibitor For Human Topoisomerase Iiᶐ, Shayna Sandhaus, Rosella Taylor, Tiffany Edwards, Alexis Huddleston, Stephen J. Beebe, Alvin A. Holder

Bioelectrics Publications

A novel complex, [Cu(acetylethTSC)Cl]Cl · 0.25C₂H₅OH 1 (where acetylethTSC = (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide), was shown to have anti-proliferative activity against various colon and aggressive breast cancer cell lines. In vitro studies showed that complex 1 acted as a poison inhibitor of human topoisomerase IIᶐ which may account for the observed anti-cancer effects.

Mixed Ligand Approach To Design Heterometallic Single-Source Precursors For Low-Temperature Preparation Of Oxide Materials, Craig Matthew Lieberman

Legacy Theses & Dissertations (2009 - 2024)

There is a considerable interest in the use of metal oxides for development of novel high-technological materials such as gas sensors, multiferroics, and electrocatalysts. In particular, the design of complex oxides, which incorporate more than one type of metal atom, is focused on enriching chemical and physical properties of the target materials and allowing for increased functionality. In order to replace the harsh conditions associated with traditional synthetic routes that often require high temperatures and/or pressures, new soft chemistry methods for the preparation of mixed-metal oxide materials have been developed. One of the most promising directions is the emergence of …

Synthesis, Characterization, Biological Studies, And Molecular Modeling Of Mixed Ligand Bivalent Metal Complexes Of Schiff Bases Based On $N$-Aminopyrimidine-2-One/2-Thione, Hati̇ce Gamze Soğukömeroğullari, Tuğba Taşkin Tok, Feyza Yilmaz, İsmet Berber, Mehmet Sönmez

Turkish Journal of Chemistry

New mixed Schiff bases, Cu(II), Co(II), Ni(II), and Mn(II) complexes, were synthesized derived from 5-chloro-2-hydroxyacethophenone and 1-amino-5-benzoyl-4-phenyl-1H-pyrimidine-2-one/thione. These complexes were characterized by elemental analysis, magnetic measurements, molar conductivity, IR, electronic, NMR, and mass spectral studies. All the complexes showed nonelectrolytic behavior. Moreover, the newly synthesized mixed ligand complexes were evaluated for their in vitro antimicrobial efficiency against bacteria and yeast. The compound named Co(L$_{1}$L) had good antifungal activity against Candida species, but no profound antibacterial effect against bacterial strains. In addition, the ground state geometries of the complexes were optimized using a semi-empirical method at PM6 level, which is a …

Synthesis, Spectral Characterisation, Electrochemical, And Fluorescence Studies Of Biologically Active Novel Schiff Base Complexes Derived From E-4-(2-Hydroxy-3-Methoxybenzlideneamino)-N-(Pyrimidin-2-Yl)Benzenesulfonamide, Valarmathy Govindaraj, Subbalakshmi Ramanathan

Turkish Journal of Chemistry

A new Schiff base was prepared from 2-sulphanilamidopyrimidine and 2-hydroxy-3-methoxybenzaldehyde in ethanolic media and it was complexed with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions. The synthesised ligand and complexes were characterised by IR, UV, ^1H and ^{13}C NMR, elemental analysis, cyclic voltammetry, EPR, molar conductance, and magnetic susceptibility. The reasonable shifts in FT-IR and NMR spectral signals of the complexes with respect to the free ligand confirm good coordination of the Schiff-base ligand with the metal through imine nitrogen and oxygen atoms of Schiff base moiety. The Schiff-base ligand and the complexes were screened for antimicrobial activity and fluorescent …

Enhanced Structural Support Of Metal Sites As Nodes In Metal-Organic Frameworks Compared To Metal Complexes, Sanjit Das

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crystalline porous materials have gained long-standing interest for their application in gas storage, separation and catalysis. These materials have been useful for domestic, scientific and industrial purposes for many decades. Zeolites are a well known example of such materials.

Metal-organic frameworks are a new class of crystalline porous materials. They have many advantages over the more widely known zeolites. Though metal-organic frameworks are relatively new, their basic structure, known as the secondary building unit, very closely resembles the structure of metal complexes. Such metal complexes have been characterized in chemistry for more than a century.

Chemical catalysis is a process …

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 …

Synthesis, Characterization, And Fluorescence Study Of Phthalhydrazidylazo Derivative Of An Unsaturated Diketone And Its Metal Complexes, Radhika Pallikkavil, Muhammed Basheer Ummathur, Krishnannair Krishnankutty

Turkish Journal of Chemistry

The coupling of diazotized luminol with the unsaturated diketone 1,7-diphenylhepta-4,6-diene-1,3-dione yielded a new type of tridentate ligand (H_2L). Analytical, IR, ^1H NMR, and mass spectral data indicate the existence of the compound in the intramolecularly hydrogen-bonded keto-hydrazone tautomeric form. Dibasic tridentate coordination of the compound in its [ML(H_2O)] complexes [M = Cu(II), Ni(II) and Zn(II)] was established on the basis of analytical and spectral data. The Ni(II) and Zn(II) chelates are diamagnetic while Cu(II) complex showed normal paramagnetic moment. The fluorescence maxima of the compound in different solvents show that the emission wavelength increases with increases in the polarity of …

Synthesis, Characterization, And Antimicrobial Activity Of A New Pyrimidine Schiff Base And Its Cu(Ii), Ni(Ii), Co(Ii), Pt(Ii), And Pd(Ii) Complexes, Mehmet Gülcan, Mehmet Sönmez, İsmet Berber

Turkish Journal of Chemistry

A new Schiff base, {1-[(5-bromo-2-hydroxy-benzylidene)- amino]-4-phenyl-2-thioxo-1,2-dihyro-pyrimidin-5-yl}-phenyl-methanone, was synthesized from N-amino pyrimidine-2-thione and 5-bromsalicylaldehyde. Metal complexes of the Schiff base were prepared from acetate salts of Cu(II), Ni(II), Co(II), Pd(II), and PtCl_2 in methanol. The chemical structures of the Schiff base ligand and its metal complexes were confirmed by spectroscopic analysis. All of the compounds were evaluated for their antimicrobial against 4 gram-positive bacteria, 1 gram-negative bacterium, and 3 yeast strains. The Schiff base and the Cu(II) and Co(II) complexes showed good biological activity against all tested bacteria and yeast strains.

Developing Dimetal Paddlewheel Complexes For Catalytic Applications, Margaret E. Napier

Legacy Theses & Dissertations (2009 - 2024)

Although there are countless examples of rhodium-catalyzed organic reactions in the chemical literature, the field continues to develop at a steady pace, as focus shifts taking advantage of economy of resources while maintaining efficiency of the catalytic reactions. The work presented is separated into three chapters, with each describing a specific approach to the development of new materials which can provide either a direct economy of resources and reagents or can be used for heterogenization of catalytic systems.

Synthesis, Characterization, And Biological Activity Studies Of (E)-N'-((Thiophen-2-Yl)Methylene)Benzofuran-2-Carbohydrazide And Its Metal(Ii) Complexes, Madappa B. Halli, Vijayalaxmi B. Patil, Sumathi R. Bevinamarada

Turkish Journal of Chemistry

Metal complexes of the type MLX_2, where M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II), and X = Cl and L = TMBC, Schiff base derived from the condensation of benzofuran-2-carbohydrazide with thiophene-2-aldehyde were synthesized. The structure of the complexes was proposed in light of analytical, IR, UV-Vis, ^1H-NMR, FAB-MS, ESR spectral data, and magnetic studies. The complexes were soluble in DMF and DMSO. The measured molar conductance values indicated that the complexes were nonelectrolytic in nature. On the basis of these studies, 6 coordinated octahedral polymeric structures were assigned to the Co(II), Ni(II), and Cu(II) complexes, and 4 …

Bowl-Shaped Polyaromatic Hydrocarbons (Buckybowls) : Crystal Packing And Metal Binding Reactions, Alexander S. Filatov

Legacy Theses & Dissertations (2009 - 2024)

This work is a part of a broad program in our laboratory dedicated to the investigation of a new class of non-planar polyaromatic hydrocarbons that map onto the surfaces of fullerenes (and referred to as buckybowls). It focuses on the preparation of buckybowls, their molecular and solid state structures, and reactivity in metal binding reactions. For the first time, the structures of all available buckybowls have been analyzed using X-ray diffraction data collected in the course of this work, as well as data previously obtained in our group or reported by others (and dearchived from the Cambridge Structural Database). Forces …

Synthesis, Characterization, And Antibacterial Activity Of Some Transition Metals With The Schiff Base N-(2-Furanylmethylene)-3-Aminodibenzofuran, Aurora Reiss, Stelian Florea, Theodor Caproiu, Nicolae Stanica

Turkish Journal of Chemistry

This paper presents the structure and antibacterial properties of some complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) with a new Schiff base N-(2-furanylmethylene)-3- aminodibenzofuran. The structure of each complex was characterized by spectroscopic methods (IR, UV-Vis, ^1H-NMR, and ESR), conductometric and magnetic data, and thermogravimetric and elementary analysis. According to these data, we propose an octahedral geometry for Co(II), Ni(II), and Cu(II) complexes, and a tetrahedral geometry for Zn(II), Cd(II), and Hg(II) complexes. Antibacterial activity of the ligand and its complexes was tested against selected bacteria. The ligand and all the complexes possess antimicrobial activity, and antimicrobial activity …

Synthesis, Characterization, And Antibacterial Effect Of 4-Methoxy-2-(5-H/Me/Cl/No_2-1h-Benzimidazol-2-Yl)- Phenols And Some Transition Metal Complexes, Aydin Tavman, Serkan İki̇z, Arzu Funda Bağcigi̇l, N. Yakut Özgür, Seyyal Ak

Turkish Journal of Chemistry

4-Methoxy-2-(5-H/methyl/chloro/nitro-1H-benzimidazol-2-yl)-phenol(HL_X; X=1-4) ligands and HL_1 complexes with Fe(NO_3)_3, Cu(NO_3)_2, AgNO_3, and Zn(NO_3)_2 were synthesized and characterized. The structures of the compounds were confirmed on the basis of elemental analysis, molar conductivity, magnetic moment, FT-IR, UV-visible, and ^1H- and ^{13}C-NMR. Antibacterial activity of the free ligands, their hydrochloride salts, and the complexes was evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimum inhibitory concentration (MIC) dilution method, against 9 bacteria, and the results were compared with penicillin-G and oxytetracycline. It was observed that HL_1, [Ag(HL_1)](NO_3), and [Cu(L_1)_2](H_2O)_2 are effective on S. epidermidis, S. aureus, and …

In-Vivo Delivery Of Dna Vaccines Using Metallo-Lipid Nanoparticles, Clarissa Sara Gomez

Open Access Theses & Dissertations

There has been a rapidly growing area of research in the design and synthesis of molecules that self-organize in water to form functional nanosystems and due to the high interest in the area metal ligand complexes were tested as drug delivery systems with a Leishmania vaccine. Herein, we present the design, synthesis and functional activity of Cu(II) and Zn(II) complexes that self-assemble in water to form spherical nanoscale structures that exhibit an affinity to bind DNA and deliver it into eukaryotic cells with a high percent efficiency in-vitro. In order to assess the effectiveness of these nanoparticles to deliver DNA …

Synthesis And Physico-Chemical And Spectroscopic Investigations Of Sodium Dihydrobis(1,2,3-Benzotriazolyl)Borate Ligand And Its Transition Metal Complexes, . Lutfullah, Ahmad Umar, Mohammed Muzibur Rahman, Mohammad Mansoob Khan, Yoon Bong Hahn

Turkish Journal of Chemistry

The title ligand, sodium dihydrobis(1,2,3-benzotriazolyl)borate, Na[H_2B(BTz)_2], was synthesized by refluxing 1 mole of sodium borohydride with 2 moles of 1,2,3- benzotriazole in toluene. The ligand shows ample reactivity towards Cr(III), Mn(II), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) metal ions and forms stable complexes. The ligand and its metal complexes were characterized by physico-chemical and spectroscopic techniques. All the complexes of divalent metal ions are tetrahedral except for Cu(II), which has been proposed to have a square-planar geometry. The complexes of Cr(III) and Fe(III) appear to have an octahedral geometry. The magnitude of molar conductance of 10^{-3} M …

Synthesis, Physico-Chemical And Spectroscopic Investigations Of Sodium Dihydrobis(1,2,3-Benzotriazolyl)Borate Ligand And Its Transition Metal Complexes, Mohammad Mansoob Khan Dr, M. M. Rahman, Y. B. Hahn

Dr. Mohammad Mansoob Khan

The title ligand, sodium dihydrobis(1,2,3-benzotriazolyl) borate, Na[H2B(BTz)2],was synthesized by refluxing 1 mole of sodium borohydride with 2 moles of 1,2,3- benzotriazole in toluene. The ligand shows ample reactivity towards Cr(III), Mn(II), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) metal ions and forms stable complexes. The ligand and its metal complexes were characterized by physico-hemical and spectroscopic techniques. All the complexes of divalent metal ions are tetrahedral except for Cu(II), which has been proposed to have a square-planar geometry. The complexes of Cr(III) and Fe(III) appear to have an octahedralge ometry. The magnitude of molar conductance of 10−3 M …

Synthesis And Reactivity Of Gold Thiolate Cluster Complexes, Hanan Abdou

Electronic Theses and Dissertations

Chemical oxidation of dinuclear gold(I) thiolates of the formula LLAu₂(SC₆H₄CH₃)₂ [LL= dppp, bis(dipheny1phosphine)propane and dppb, bis(dipheny1phosphine)butane] and dinuclear gold(I) thiolate complexes with bridging a propane dithiolate ligand of the formula LLAu₂(SC₃H₆S) [LL = dppp and dppb] was carried out using the mild oxidizing agent, ferrocenium, [Cp₂Fe]PF6). Spectroscopic studies and elemental analysis showed the formation of gold(I) clusters, disulfide, and ferrocene as products of this oxidation reaction. The clusters, [(dppp)AU₂(SC₆H₄CH₃)](PF₆) and [(dppb)Au₂(SC …

Electrochemical Studies Of Metal Complexes In Solution, Yexiang Tong, Beisheng Kang, Qiqin Yang

Journal of Electrochemistry

The prospectus of electrochemical studies of metal complexes in solution have been introduced as a background of our research work. The electrochemical behaviors of the metal complexes and clusters have been investigated by many kinds of electrochemical methods.The content includes the standard electrode potential and the related equilibrium constant, electrochemical kinetics and the related behavior of structure, electrocatalysis and electrosynthesis of metal complexes. The electrode reaction mechanisms of the complexes have been approached. The methods for measuring some thermodynamic and kinetic parameters of the complexes are also given. Electrochemical studies would provid many kinds of important information for studying the …