Inorganic Chemistry Commons^™

Bridging The 12-6-4 Model And The Fluctuating Charge Model, Pengfei Li

Chemistry: Faculty Publications and Other Works

Metal ions play important roles in various biological systems. Molecular dynamics (MD) using classical force field has become a popular research tool to study biological systems at the atomic level. However, meaningful MD simulations require reliable models and parameters. Previously we showed that the 12-6 Lennard-Jones nonbonded model for ions could not reproduce the experimental hydration free energy (HFE) and ion-oxygen distance (IOD) values simultaneously when ion has a charge of +2 or higher. We discussed that this deficiency arises from the overlook of the ion-induced dipole interaction in the 12-6 model, and this term is proportional to 1/r …

Visible Light Generation And Mechanistic Investigation Of High-Valent Metal-Oxo Species Supported By Different Ligands, Seth Ellis Klaine

Masters Theses & Specialist Projects

Numerous transition metal catalysts have been designed as biomimetic model compounds for the active site of metalloenzymes found throughout Nature, most notably cytochrome P450 monooxygenases that carry out the oxidative transformations of organic substrates with near-perfect chemo-, regio-, and stereo-selectivity. The primary active oxidants in catalytic and enzymatic cycles are fleeting high-valent metal-oxo intermediates where the oxo ligand can transfer to an organic substrate in a process known as oxygen atom transfer (OAT).

In the present work, porphyrin-manganese(III), salen-chromium(III), and salenmanganese( III) derivatives were successfully synthesized and spectroscopically characterized using 1H NMR and UV-Vis spectroscopies. A facile photochemical approach was …

Leaving Ligand Effects On Reactivity And Solubility Of Monofunctional Platinum(Ii) Anticancer Complexes, Heidi Linn Hruska Millay

Masters Theses & Specialist Projects

Monofunctional platinum(II) complexes, such as phenanthriplatin and pyriplatin, have notably different characteristics from the bifunctional anticancer complexes, such as cisplatin and oxaliplatin, which have detrimental toxicities and resistance associated with them. The unique properties of the monofunctional complexes may be exploited to target cancer cells without producing the toxic side effects associated with the current FDA-approved platinum-based anticancer drugs. To advance the understanding of these monofunctional platinum(II) complexes, this study replaced the chloride leaving ligand with an acetate group, which should increase solubility and alter the rate of reactivity with key amino acid and nucleotide targets. Phenanthriplatin and pyriplatin compounds …

Synthesis, Kinetic And Catalytic Studies Of Manganese Complexes With Corrole And Porphyrin Ligands, Haleh Jeddi

Masters Theses & Specialist Projects

High-valent transition metal-oxo intermediates play a significant role in the catalytic cycle of the ubiquitous cytochrome P450 enzymes and in biomimetic catalytic systems. In this work, manganese(III) porphyrin and corrole systems (2) were synthesized and characterized by UV-vis absorbance and 1H-NMR, matching literaturereported spectroscopic data. Manganese(V)-oxo corroles (3) and a manganese(IV)-oxo porphyrin (4) were successfully generated by chemical oxidation using mchloroperoxybenzoic acid (m-CPBA), and their oxidation reactions with organic reductants were comparatively investigated. Results from single-turnover kinetic studies indicate that in the tris(pentafluorophenyl)corrole system (3a), the active oxidizing intermediate differs in different solvents. The active oxidizing intermediate in acetonitrile is …

The Effects Of Carrier Ligands On Cisplatin Binding To Cysteine And Methionine, Adam C.R Smith

Masters Theses & Specialist Projects

We have reacted several derivatives of the anticancer drug cisplatin with N-acetyl-Lcysteine (N-AcCys) and N-acetyl-L-methionine (N-AcMet), which are two of the primary amino acid targets of platinum. NMR spectroscopy was used to monitor the reactions and determine the effect the different ligands would have on the platinum reactivity. Several of the platinum compounds were tested at pH of 4 and 7, and with platinum:amino acid ratios of 1:1, 2:1 and 1:2. Competition reactions between cysteine and methionine were done to confirm which would react with the platinum compound first. [Pt(dien)(NO3)]+ reacts faster with methionine than with cysteine at both pH …

Effects Of Binding Affinity Between Bovine Serum Albumin And Platinum Drugs, Nathan Puckett

Masters Theses & Specialist Projects

Platinum complex drugs such as cisplatin have been used as highly successful chemotherapy drugs since the 1970s. We are interested in how the ligands attached to cisplatin analogs influences their reactivity with biologically relevant targets along with time and amount. For this study, reactions were conducted to determine the reactivity between different platinum compounds and the protein bovine serum albumin. Various platinum compounds with different ligands were reacted in varying amounts with albumin in ammonium acetate buffer for either 1 hour, 4 hours, or 24 hours. Each reaction was quenched after the designated reaction time by dialysis and the platinum …

Visible-Light Generation Of High-Valent Metal-Oxo Intermediates And A Biomimetic Oxidation Catalyzed By Manganese Porphyrins With Iodobenzene Diacetate, Ka Wai Kwong

Masters Theses & Specialist Projects

High-valent iron-oxo intermediates play central roles as active oxidants in enzymatic and synthetic catalytic oxidations. Many transition metal catalysts are designed for biomimetic studies of the predominant oxidation catalysts in Nature, the cytochrome P450 enzymes.

In this work, a new photochemical method to generate high-valent iron-oxo porphyrin models was discovered. As controlled by the electronic nature of porphyrin ligands, iron(IV)-oxo porphyrin radical cations (Compound I model) and iron(IV)-oxo porphyrin derivatives (Compound II model) were produced. These observations indicate that the photochemical reactions involve a heterolytic cleavage of O-Br in precursors to give a putative iron(V)-oxo intermediate, which might relax to …

Synthetic Investigation On The Biomimetic Metal-Catalyzed Sulfoxidations And Photochemical Generation Of A Highly Reactive Ruthenium(V)-Oxo Porphyrin, Weilong Luo

Masters Theses & Specialist Projects

Catalytic oxidation plays a crucial role in current chemical and pharmaceutical industries which is also a leading technology for green chemical processes. In Nature, the ubiquitous cytochrome P450 enzymes can catalyze a wide variety of oxidation reactions with high efficiency and selectivity. Many transition metal catalysts are designed as the biomimetic model of cytochrome P450 enzymes. In this work, series of metalloporphyrins and metallocorroles have been successfully synthesized to investigate and develop catalytic selective oxidation of sulfides to sulfoxides.

Manganese(III) porphyrin complexes (2) and manganese(III) corrole complexes (6) with iodobenzene diacetate [PhI(OAc)2] as a mild oxygen source exhibited remarkable catalytic …

Synthesis And Characterization Of Bis-Phosphine Complexes With Transition Metals, Alicia L. Mcdaniel

Masters Theses & Specialist Projects

Extractants and extraction methodologies play a vital role in many industrial processes, from the concentration of precious metals from ores to the separation of longlived nuclei from radioactive waste as well as the removal of heavy metals from soils and water for remediation. The vast majority of extractants rely on the use of nitrogen, oxygen, sulfur or selenium as Lewis base donor atoms to form coordination complexes with the metal ions of interest. These extractants often make use of the chelate effect and/or the macrocyclic effect in order to form stable complexes. Some of the best known types of chelate …

Dioxidobis(2-Oxo-1,2-Dihydropyridin-3-Olato)­Molybdenum(Vi), Manoj Trivedi, Daya Pandey, Nigam Rath

Chemistry & Biochemistry Faculty Works

In the title compound, [Mo(C5H4NO2)2O2], the MoVI atom exhibits a distorted octa­hedral coordination geometry formed by two terminal oxo ligands and two monoanionic O,O-bidentate pyridinone ligands. The two terminal oxo ligands lie in a cis arrangement, the ketonic O atoms of the pyridinone ligands are coordinated trans to the oxo ligands and the deprotonated hydroxyl O atoms are located trans to each other. The crystal structure contains inter­molecular N-H...O hydrogen bonds, C-H...O contacts and face-to-face [pi]-[pi] stacking inter­actions with an inter­planar separation of 3.25 (1) Å.

Water Chemistry Survey Of Boulder Basin, Lake Mead, P. R. Tramutt, Bureau Of Reclamation

Publications (WR)

The survey results indicate that the impoundment of water behind Hoover Dam has not adversely affected the dissolved oxygen (DO) content and that water quality and DO content were uniform regardless of depth. The study made in April-May 1964 will provide water quality data of Lake Mead prior to releases from Lake Powell as a basis for evaluating Lake Powell's effect on water quality and limnology of Lake Mead. The performance of a DO analyzer was tested and found unsatisfactory at depths below 150 ft. Parameters tested by standard chemical analyses of water samples in the Denver Laboratory and by …