Inorganic Chemistry Commons^™

Synthesis, Characterization And Crystal Growth Of I2-Ii-Iv-Vi4 And I4-Ii-Iv2-Vi7 Diamond-Like Semiconductors With Potential In Ir-Nlo Applications, Jennifer Glenn

Electronic Theses and Dissertations

In this dissertation, several new and existing diamond-like semiconductors (DLSs) were synthesized and investigated for their potential in infrared nonlinear optical (IR-NLO) applications. In Chapter 2 growth of large single crystals of Li₂MnGeS₄ was carried out using iodine vapor transport and a newly created graphite-tube containment system. This crystallization method produced sizable single crystals on the scale of 2x1x1 mm³, that were used to determine the material’s magnetic properties. Magnetization data indicate that the compound is antiferromagnetic with a Néel temperature of 10 K and an effective magnetic moment of 5.6 /f.u.. The specific heat …

Development Of Granulated Adsorbent For Clean-Up Of Water Contaminated By Cesium, Esther Alorkpa

Electronic Theses and Dissertations

A study was conducted on sol-gel synthesis of an adsorbent (phosphotungstic acid embedded in silica gel, H-PTA/SiO­₂) of radioactive cesium. A novelty of this work is covalent bonding of PTA to the surface of solid support that prevents leaching from the surface of the material. The sample was granulated with a binder, aluminium oxide (γ-Al₂O₃). Solid-state NMR and FT-IR spectroscopy were used to confirm the presence of Keggin units of PTA in the bound materials. Thermal analysis of H-PTA/SiO­₂ - γ-Al₂O₃ (50 %) showed that the water content in the …

Electro- And Photocatalytic Carbon Dioxide Reduction And Thermal Isomerization Of Highly Strained Tricyclocompounds, Weiwei Yang

Electronic Theses and Dissertations

Anthracene-bridged dinuclear rhenium complexes are reported for electrocatalytic and photocatalytic carbon dioxide (CO2) reduction to carbon monoxide (CO). Related by hindered rotation of each rhenium active site to either side of the anthracene bridge cis and trans conformers have been isolated and characterized. Electrochemical studies reveal distinct mechanisms whereby the cis conformer operates via cooperative bimetallic CO2 activation and conversion and the trans conformer reduces CO2 through well-established single-site and bimolecular pathways analogous to Re(bpy)(CO)3Cl. Higher turnover frequencies are observed for the cis conformer (35.3 s−1) relative to the trans conformer (22.9 s−1) with both outperforming Re(bpy)(CO)3Cl (11.1 s−1). Photocatalytic …

X-Ray Crystal Structure Of Au36(Sph-Pch3)24 Nanomolecules, Vigneshraja Ganeshraj

Electronic Theses and Dissertations

Au36(SR)24 is one of the most comNanomolecules (NM) in gold NM field and crystal structures of Au36(SR)24 with different thiolate protecting ligand such as tert-butylbenzene thiol, thiophenol and cyclopentane thiol have been reported. It has been predicted that aromatic thiol protected Au36(SR)24 NM have same core structures like the other reported Au36(SR)24 NMs. Due to the steric and electronic conjugation effects the staples on the gold core exhibit minor changes in the bond length without affecting the gold core. By varying the Gold:Thiol ratio the NM size can be controlled. Herein, we report the synthesis, isolation and characterization of two …

Synthesis And Characterization Of Zinc(Ii) Dipyrrin Photosensitizers, Norah Alqahtani

Electronic Theses and Dissertations

Photocatalytic carbon dioxide reduction transforms CO2 to useful chemicals and fuels, reducing CO2 emissions and making fossil fuels more renewable. Due to a lack of earthabundant sensitizers, we want to design new earth-abundant sensitizers to go with the many known carbon dioxide reduction catalysts. Zn(II) dipyrrin complexes strongly absorb visible light, but their excited state properties have not been widely studied. To investigate their photophysical properties, two Zn dipyrrin complexes, with and without heavy atoms, were synthesized and characterized by NMR and mass spectrometry. The photophysical properties of the two complexes were measured in polar and non-polar solvents, particularly fluorescence …

Steric Effects Of Alkyl Ammonium Salts On The Combustion Of Exchanged Smectite Clays, Celeste A. Keith

Electronic Theses and Dissertations

Bomb calorimetry was explored as a new method for determining the cation exchange capacity (CEC) of clays. Smectite clays were modified with several alkyl ammonium salts varying in number of carbons and the spatial orientation of the carbons about the central nitrogen atom. The clays used, standards purchased from the Source Clay Repository, have CECs of 44, 80, 88, and 120 meq/100 g. Theoretically, the combustion energy of the organo-clays should be approximately the same for each salt. Any differences in energy would be due to the different structures of the salts and how they are oriented in the interlamellar …

Evaluating Ligand Assisted Activation Of Small Molecules Through Proton Reduction And Alcohol Oxidation., Rahul Jain

Electronic Theses and Dissertations

Hydrogen is a potential alternate to the carbon fuels to meet the future demands for energy in an eco-friendly manner. Hydrogen produced by the electrolysis of water is stored in fuel cells which on demand can be converted into electrical energy upon the reaction with oxygen. In the quest for economically viable electrocatalysts for hydrogen evolution, the work in this dissertation describes evaluation of nickel based catalysts coordinated to redox active ligands, dialkyl/diarylphosphine benzenethiol and bis(thiosemicarbazone) for their ability to generate hydrogen with external acids as a proton source. A nickel complex with the benzenethiol ligand framework follows a traditional …

Controlled Electrochemical Synthesis Of Single One-Dimensional Metal Nanochains Across Microgap Electrodes., Amareshwari Konutham

Electronic Theses and Dissertations

This study mainly focuses on the fabrication of single one dimensional (1D) NP chains across the 5-micron gap of Au two electrode devices (TED). This has been achieved by electrochemical deposition of Ag onto the two electrodes, soaking the TED in 0.1 M Cetyltrimethyl ammonium bromide for 2-3 hours, and then close monitoring of the current as a function of time while a voltage across the two Ag coated Au electrodes in air. One dimensional Ag nanoparticle chain formation occurred by oxidation of Ag to Ag⁺ at the positive electrode followed by movement of Ag⁺ ions to the …

Homogeneous Ligand-Centered Hydrogen Evolution And Hydrogen Oxidation : Exploiting Redox Non-Innocence To Drive Catalysis., Andrew Z. Haddad

Electronic Theses and Dissertations

Hydrogen is a promising carbon-free fuel / energy carrier and is an essential building block for many industrial and agricultural processes. Rising energy demands have ignited interest in the development of carbon-free and carbon neutral energy sources. In this context, hydrogen is an attractive candidate—being energy-dense, carbon-free—and easily accessible through a two-electron reduction of water. Accordingly, many electrochemical homogeneous catalyst systems have been studied, with a focus on understanding the mechanism of hydrogen evolution proceeding through metal-hydride intermediates. However, there has been a renaissance in hydrogen evolution reaction (HER) catalyst design, with many groups implicating ligand redox non-innocence as a …

Functionalized Silica Gel For Adsorption Of Cesium From Solution, Kenneth Marshall Seaton Iii

Electronic Theses and Dissertations

Mesoporous silica gel containing embedded phosphotungstic acid (PTA) was synthesized by sol-gel co-condensation of tetraethyl orthosilicate with PTA in acidic media. The obtained material had high Brunauer-Emmett-Teller Theory (BET) surface area and pore volume. A characteristic band of the Keggin structure of PTA was present in its FT-IR spectrum while its X-ray diffraction patterns were absent. This proved the embedding of PTA on a sub-molecular level and not as a second phase. Acidic sites were determined by neutralization with base in aprotic solvent, followed by titration of the remaining base with an acid. The material demonstrated high adsorption capacity of …

Nitrogen-Containing Materials For Mechanochemical Synthesis, Luminescence Analysis, And Heterogeneous Catalysis, David Nash

Electronic Theses and Dissertations

Various inorganic nitrogen-containing materials have been exploited for their different properties. Several nitride materials are commercially attractive due to their mechanical properties making them suitable for ceramic industries and wide bandgaps fitting for use as semiconductor and insulator materials, as well as optoelectronics. Nitride materials can exhibit versatility in applications such as the use of gallium nitride to make blue LEDs, nitrides of titanium and silicon being utilized as medical implants for their chemical inertness and hardness, and the heavy use of boron nitride as a solid lubricant in the cosmetic industry. Amines have been used as nitrogen-containing organic ligands …

Synthesis And Characterization Of Imidazolo 3,1- Tetrakis (N-Phenylacetamidato) Dirhodium (Ii) And A Crystallographic Study Of A Copper And Two Molybdenum Model Cofactors, Gabriel I.G. Thompson

Electronic Theses and Dissertations

Imidazole was reacted with 3,1-tetrakis (N-phenlyacetamidato) dirhodium (II) to explore the chemistry of asymmetric dirhodium catalysts. The imidazolo 3,1-tetrakis (Nphenlyacetamidato) dirhodium (II) complex was synthesized and then characterized by Nuclear Magnetic Resonance and Ultraviolet-Visible spectroscopies as well as by single crystal X-ray Diffraction. Additionally, one copper and two molybdenum model cofactors were characterized by XRD to better understand their structure/function relationships. NMR results gave evidence of the formation of the 3,1-imidazole complex, and UV-Vis indicated that even in large excess imidazole was coordinated only to one axial site. The structure of the 3,1-imidazole complex was confirmed by XRD with the …

Synthesis And Characterization Of Five New Tetrakis(N-Phenylacetamidato) Dirhodium(Ii) Amine Complexes And One Molybdenum Cofactor Described Crystallographically, Cragin K. Harris

Electronic Theses and Dissertations

Six new crystal structures were determined using a Rigaku Mercurcy 375/MCCD(XtaLab mini) diffractometer. The structure of a molybdenum cofactor was solved resulting in an R1 (R1 = Σ ||Fo| - |Fc|| / Σ |Fo|) of 3.61% despite the presence of a disordered DMSO molecule. New Tetrakis(N-phenylacetamidato) Dirhodium(II) complexes were synthesized and characterized. Two 2,2-cis-[Rh2(NPhCOCH3)4]•(C3H4N2)x where x= 1 or 2 were successfully crystallized and solved with R1 values below 5%. Additional studies were conducted via NMR to observe formation of both products. Three potential catalysts were synthesized starting with 3,1-[Rh₂(NPhCOCH₃)₄]. The resulting compounds were a …

Synthesis And Characterization Of 2,2-Cis-[Rh2(Nphcoch3)4]•Ncc6h4r Where R = H, 2-Ch3, 3-Ch3, 4-Ch3 And [Rh2(O2cch3)(Nphcocf3)3], Fredricka F. Quarshie

Electronic Theses and Dissertations

Five novel compounds were synthesized and characterized. Crystal structures were determined using Rigaku Mercury 375/MCCD(XtaLAB mini) diffractometer with graphite monochromated MoKα radiation. The crystal structures of [Rh₂(NPhCOCH₃)₄•xNCC₆H₄R where x = 1 or 2 and R=H, 2-CH₃,3-CH₃ and 4-CH₃ were solved to an R₁ value of less than 5 (R₁= Σ||F_o| - |F_c|| / Σ |F_o|). In each of the nitrile complexes, the rhodium is five or six coordinate and possesses pseudo D_4h symmetry. The complexes were …

Synthesis And Characterization Of A New Cyano-Substituted Tris(Pyrazolyl)Borate And Its Thallium(I) Complex, Bozumeh Som

Electronic Theses and Dissertations

A new cyanoscorpionate - tris(4-cyano-3,5-diphenylpyrazolyl)borate (Tp^Ph2,4CN) has been synthesized and characterized. The thallium complex of this ligand TlTp^Ph2,4CN has also been prepared and characterized by FT-IR, ¹H NMR, and single-crystal X-ray-diffraction. The complex TlTp^Ph2,4CN crystalized in the monoclinic space group C2/c with unit cell a = 14.6697(10) Å, b = 13.9493(10) Å, c = 19.3347(12) Å, and b= 91.761(2)°. Structural comparison of TlTp^Ph2,4CN with analogous complexes demonstrated the effects of both steric and electron-withdrawing substituents on coordination geometry and the electronic properties of the metal ion. There were short contacts between the cyano groups …

Synthesis And Characterization Of Three New Tetrakis(N-Phenylacetamidato) Dirhodium(Ii) Nitrile Complexes, Nkongho Atem-Tambe

Electronic Theses and Dissertations

Three new tetrakis [Rh₂(PhNCOCH₃)₄·xNCR] (R = {2-CH₃}C₆H₄ (x=2), R = {3-CH₃}C₆H₄ (x=1), R = (3-CN)C₆H_4∞ (x=1)) complexes have been synthesized and characterized. These complexes were characterized by IR and ¹H NMR spectroscopies and X-ray crystallography which solved with R₁<0.05.

[Rh₂(PhNCOCH₃)₄·2NC{2-CH₃}C₆H₄] was triclinic (a=9.79Å, b=14.79Å, c=16.36Å, α=103.84⁰, β=99.17⁰, γ=99.77⁰, P-1(#2), μCN=2227.78cm^-1, Rh-Rh=2.42Å, N-C=1.13Å, 1.14Å, Rh-N=2.34Å, 2.35Å, Rh-N-C=151.6⁰, 152.5⁰, Rh-Rh-N=173.0⁰, 174.6⁰).

[Rh₂(PhNCOCH₃)_{4 …}

X-Ray Crystal Structures Of: [Rh2(N-{2,4,6-Ch3}C6h2)Coch3)4]•2ncc6h4 And Ba1.5[Fe(C10h13n2o7)][Co(Cn)6]•9h2o; Two Crystallographic Challenges, Kenneth K. Kpogo

Electronic Theses and Dissertations

The novel compound, [Rh₂(N-{2,4,6-CH₃}C₆H₂)COCH₃)₄] was synthesized. Crystal structures of [Rh₂(N-{2,4,6-CH₃}C₆H₂)COCH₃)₄]·2NCC₆H₅ and Ba_1.5[Fe(C₁₀H₁₃N₂O₇)][Co(CN)₆]·9H₂O were determined employing a Rigaku Mercury375R/M CCD (XtaLAB mini) diffractometer with graphite monochromated Mo-Kα radiation. For [Rh₂(N-{2,4,6-CH₃}C₆H₂)COCH₃)₄]·2NCC₆H₅, the space group was P-421c(#114) with unit cell dimensions: a =11.0169(14)Å, c =21.499(3)Å, V …

Quenching Of The Fluorescence Of Tris (2 2-Bipyridine) Ruthenium(Ii) [Ru(Bipy)3]2+ By A Dimeric Copper(Ii) Complex., Kevin E. Cummins

Electronic Theses and Dissertations

The quenching of the [Ru(bipy)₃]²⁺ by Cu₂L²⁺ was studied and the data were plotted with the Stern-Volmer equation. The plot showed a break and was divided into 2 regions, <0.5 and >0.5 Cu₂L²⁺: [Ru(bipy)₃]²⁺ molar ratio. Quenching above the 0.5 Cu₂L²⁺: [Ru(bipy)₃]²⁺ molar ratio was slower (330 x 10^-6 M^-1s^-1) than the quenching rate reaction below 0.5 ratio (387 x 10^-6 M^-1s^-1).

With Cu₂L²⁺ being a dimeric complex the …

Cyanoscorpionates And Transition Metal Complexes., Donald Martin Johnson

Electronic Theses and Dissertations

The new dihydrobis(4-cyano-3-tert-butylpyrazolylborate) ligand has been synthesized. Isolated crystals of the thallium complex were collected and structurally characterized by X-ray diffraction. Transition metal complexes of the ligand are currently under investigation.

A Study Of Oxomolybdenum Chelate Compounds Of Oxidation States (V) And (Iv) When Prepared By Photochemical Reduction Of Oxomolybdenum (Vi) Complexes In Ethanol Under Inert Atmosphere And By Chemical Reduction, Richard Donald Dendinger

Electronic Theses and Dissertations

A photolysis system was designed for meticulous exclusion of oxygen and moisture. Photolyzed ethanol solutions of dioxobis(acetylacetonato)­-molybdenum(VI), Mo0₂ (acac)₂, were studied via preparation of derivatives with several uninegative bidentate ligands (chelH, cysteine was designated cystH₂) and pyridine (py). Infrared spectroscopy was a useful tool in identifying these compounds. An oxomolybdenum(IV) compound, MoO(dtc)₂ was isolated from the red photolyzed solution when dtc was the N,N-diethyldithiocarbamate ion. Tropolone, 8-hydroxyquinoline, N,N-diethyldithiocarbamate, and cysteine formed products formulated as the dioxo bridged molybdenum(V) compounds, Mo₂0₄(che1)₂. Acetylacetone, tropolone, 8-Hydroxyquinoline and N,N-diethyldithiocarbamate, formed derivatives formulated …

The Potentiometric Determination Of Zinc In Dowmetal Alloys., James S. Goodman

Electronic Theses and Dissertations

No abstract provided.

The Effect Of Hydrogen Ion Concentration On The Color Of Metallic Chromates., John E. Morris

Electronic Theses and Dissertations

No abstract provided.