Chemistry Commons^™

Ortho-Fluoro Effect On The C–C Bond Activation Of Benzonitrile Using Zerovalent Nickel, Sébastien Lachaize, Dominique C. Gallegos, Juliana J. Antonio, Abdurrahman C. Atesin, Tülay A. Ateşin, William D. Jones

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The effect of fluoro substitution on the C–C bond activation of aromatic nitriles has been studied by reacting a variety of fluorinated benzonitriles with the nickel(0) fragment [Ni(dippe)] and by locating the reaction intermediates and transition-state structures on the potential energy surface by using density functional theory calculations with the [Ni(dmpe)] fragment (dippe = 1,2-bis(diisopropylphosphino)ethane, dmpe = 1,2-bis(dimethylphosphino)ethane). As in the previous reports, the reaction of fluorinated benzonitriles with the [Ni(dippe)] fragment initially formed an η2-nitrile complex, which then converted to the C–CN bond activation product. Thermodynamic parameters for the equilibrium between these complexes have been determined experimentally in both …

Simulating Water Adsorption In Metal–Organic Frameworks With Open Metal Sites Using The 12-6-4 Lennard–Jones Potential, Alicia Y. Leem, Haoyuan Chen

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Metal–organic frameworks (MOFs) with coordinatively unsaturated open metal sites (OMSs) are promising sorbent materials in atmospheric water harvesting (AWH) systems at low relative humidity (RH) due to their strong interactions with water molecules. However, accurate computational modelling of water adsorption in those materials are challenging, as standard force fields (FFs) based on the 12-6 Lennard–Jones (L–J) potential cannot properly describe the water–OMS interactions. In biomolecular simulations, the 12-6-4 L–J potential has been successfully used to model metal ion–water interactions in which the extra 1/r4-term is for charge-induced dipole electrostatics. In this work, we adopted this strategy and used …

Titanium Dioxide Functionalized Multi-Walled Carbon Nanotubes And Silver Nanoparticles Reinforced Polyurethane Nanofibers As A Novel Scaffold For Tissue Engineering Applications, Taha Umair Wani, Anjum Hamid Rather, Rumysa Saleem Khan, Javier Macossay-Torres, Arvind H. Jadhav, Puneethkumar M. Srinivasappa, Abdalla Abdal-Hay, Sami-Ullah Rather, Faheem A. Sheikh

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Polyurethane is a synthetic polymer that can be fabricated into nanofibers to mimic extracellular matrix properties facilitating cell attachment and growth on the fibrous network. However, enhanced hydrophilicity and high mechanical properties may improve their use in tissue engineering, suggesting additional modifications are needed. The current work presents the fabrication of polyurethane-based bone regenerative nanofibers reinforced with TiO2-MWCNT composites and harboring Ag NPs for bacterial inhibition. The fibers possessed smooth morphology with an average size ranging from 800 to 1200nm. Techniques like SEM, FTIR, XPS, XRD, EDAX, and UV-vis spectroscopy confirmed the presence of nanofiber components like TiO2-MWCNT and Ag …

Microwave-Assisted Depolymerization Of Poly (Ethylene Terephthalate) Via Ethanolysis, Mayra Alejandra Gomez Cortez

Theses and Dissertations

In the search of providing an alternative form of combating the complex environmental concerns rising from the rapid growth of poly (ethylene terephthalate) waste in the world, this research focused on investigating the chemical recycling of PET via ethanolysis. Parameters such as temperature, reaction time, catalyst usage and concentration were investigated to promote depolymerization.

In this work, ethanolysis of waste PET under microwave irradiation was investigated using organocatalysts 1,5,7-Triazabicyclo [4.4.0] dec5-ene (TBD) and 1,8-Diazabicyclo [5.4.0] underc-7-ene (DBU). We evaluated the effectiveness of reaction conditions through a series of experiments and determined the optimum conditions as follows: 0.5 g of PET, …

Cooperative Heterometallic Platforms Enabling Selective C–H Bond Activation And Functionalization Of Pyridines, Manar M. Shoshani

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The development of methodologies for regioselective C–H functionalization of N-heterocycles has seen sustained growth over the last two decades. Cooperative reactivity stemming from the addition of Lewis-acidic metals to late-transition-metal complexes has enabled regioselective catalytic transformations. Progress in the design of ligands and Lewis-acidic metal precursors has led to development of in situ cooperative catalysts able to facilitate C–H functionalization of pyridine at C-2, C-3, and C-4 positions. Very recently, focused efforts toward well-defined heterometallic complexes facilitating C-H bond catalysis have been targeted. Transformations showcasing regioselective C-2 transformations have been achieved. This perspective examines select examples delineating the evolution …

Aloe Barbadensis Rinds Employ Physical And Chemical Defense Mechanisms Against Insect Herbivores With Varying Success, Zachary Johnson, Ishveen Kaur, Fernando Castillo, Rupesh R. Kariyat, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences Faculty Publications

Plants deter herbivory through a suite of physical and chemical defenses. While most studies have focused on understanding one or the other, efficient plant defense against herbivory is often cumulative. To examine this, we used Aloe barbadensis (Asphodelaceae) as a model, since in natural settings, the species is found to be well-defended against insect herbivores. To start with, we hypothesized that the epicuticular wax potentially plays an important role in herbivore defense as the major physical defense. To test our hypothesis, we conducted bioactivity-guided extraction and polarity-based fractionation of A. barbadensis rinds. We then mixed them into an artificial diet, …

Amplifying Reactivity Of Metal Hydrides: A Heterotrimetallic Nial2(Μ2-H)2 Catalyst For The Dearomatization Of N-Heterocycles, Edgardo De Leon, Fernando Gonzalez, Preetika Bauskar, Sergio Gonzalez-Eymard, David De Los Santos, Manar Shoshani

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Identifying methods to modulate the reactivity of metal hydrides is lacking yet highly desirable given the role they play in a plethora of catalytic applications. Herein we report novel methodology to amplify the reactivity of metal hydrides through the design of well-defined heterometallic bridged hydride species. Catalytic hydroboration of quinolines was dramatically altered by the addition of a secondary metal to bridge the Al–hydride species LAlH. Specifically, the addition of Ni(COD)2 led to the formation of novel heterotrimetallic species 1 which features Ni participating in 3-center bonding with sterically accessible Al–H species and exhibits catalytic hydroboration of sterically encumbered quinolines …

Molecular Research In Pancreatic Cancer: Small Molecule Inhibitors, Their Mechanistic Pathways And Beyond, Shaila A. Shetu, Nneoma James, Gildardo Rivera-Sanchez, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Pancreatic enzymes assist metabolic digestion, and hormones like insulin and glucagon play a critical role in maintaining our blood sugar levels. A malignant pancreas is incapable of doing its regular functions, which results in a health catastrophe. To date, there is no effective biomarker to detect early-stage pancreatic cancer, which makes pancreatic cancer the cancer with the highest mortality rate of all cancer types. Primarily, mutations of the KRAS, CDKN2A, TP53, and SMAD4 genes are responsible for pancreatic cancer, of which mutations of the KRAS gene are present in more than 80% of pancreatic cancer cases. Accordingly, there is a …

The Application Of Transition Metal Sulfide Nanomaterials And Their Composite Nanomaterials In The Electrocatalytic Reduction Of Co2: A Review, Jason Parsons, Mataz Alcoutlabi

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Electrocatalysis has become an important topic in various areas of research, including chemical catalysis, environmental research, and chemical engineering. There have been a multitude of different catalysts used in the electrocatalytic reduction of CO2, which include large classes of materials such as transition metal oxide nanoparticles (TMO), transition metal nanoparticles (TMNp), carbon-based nanomaterials, and transition metal sulfides (TMS), as well as porphyrins and phthalocyanine molecules. This review is focused on the CO2 reduction reaction (CO2RR) and the main products produced using TMS nanomaterials. The main reaction products of the CO2RR include carbon monoxide (CO), formate/formic acid (HCOO−/HCOOH), methanol (CH3OH), ethanol …

Small Molecule Egfr Inhibitors As Anti-Cancer Agents: Discovery, Mechanisms Of Action, And Opportunities, Tanzida Zubair, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Epidermal growth factor receptors (EGFRs) are a class of receptor tyrosine kinase that are also called ErbB1 and HER1. EGFR tyrosine kinase activity inhibition is considered a promising therapeutic strategy for the treatment of cancer. Many small-molecule inhibitors of EGFR tyrosine kinase (EGFR-TK), from medicinally privileged molecules to commercial drugs, have been overviewed. Particular attention has been paid to the structure of the molecule and its mechanism of action if reported. Subsequent classification of the molecules under discussion has been carried out. Both natural and synthetic and reversible and irreversible EGFR-tyrosine kinase inhibitors have been discussed. Various types of cancers …

Mofx-Db: An Online Database Of Computational Adsorption Data For Nanoporous Materials, N. Scott Bobbitt, Kaihang Shi, Benjamin J. Bucior, Haoyuan Chen, Nathaniel Tracy-Amoroso, Zhao Li

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Machine learning and data mining coupled with molecular modeling have become powerful tools for materials discovery. Metal–organic frameworks (MOFs) are a rich area for this due to their modular construction and numerous applications. Here, we make data from several previous large-scale studies in MOFs and zeolites from our groups (and new data for N2 and Ar adsorption in MOFs) easily accessible in one place. The database includes over three million simulated adsorption data points for H2, CH4, CO2, Xe, Kr, Ar, and N2 in over 160 000 MOFs and 286 zeolites, textural properties like pore sizes and surface areas, and …

Implementation Of Course Structure In Stem Courses For Student Motivation And Learning, And Lab Innovation, Muzammil Arshad, Mamoona Muzammil

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The present study is an extension of implementation of the course structure which was initially designed, developed and implemented at Texas A&M University for engineering courses. This study extends its implementation to other STEM courses to assess its applicability and effectiveness in science related courses. The course structure is employed at the Chemistry department at University of Texas Rio Grande Valley (UTRGV). The present study is an autoethnography of the implementation of the course structure and its effectiveness assessment. This study highlights the implementation of the course structure considering student motivation and learning since student motivation is an important research …

Medicinal Bismuth: Bismuth-Organic Frameworks As Pharmaceutically Privileged Compounds, Shaila A. Shetu, Luis M. Sanchez-Palestino, Gildardo Rivera-Sanchez, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Historically organometallic compounds have been used to cure certain diseases with limited applications. Although bismuth belongs to the category of heavy metals, many of its derivatives have found applications in modern drug discovery research, mainly because of its low toxicity and higher bioavailability. Being an eco-friendly mild Lewis acid, compounds having bismuth as a central atom are capable of binding several proteins in humans and other species. Bismuth complexes demonstrated antibacterial potential in syphilis, diarrhea, gastritis, and colitis. Apart from antibacterial activities, bismuth compounds exhibited anticancer, antileishmanial, and some extent of antifungal and other medicinal properties. This article discusses major …

Green Synthesis Of Spiro Compounds And The Phytochemical Investigation Of Diethyl Ether Fraction Of Camu-Camu (Myrciaria Dubia) Leaves, Judith Anane

Theses and Dissertations

There are a lot of lucrative plant species found in the Amazon and camu-camu (Myrciaria dubia (H.B.K.) Mc Vaugh) is distinct among them. This is due to its exceptional Vitamin C content which varies from 1600 to 6112 mg/100g of pulp. Besides the fruits which is popularly used, different parts of camu-camu plants including the stems, leaves, seeds, barks, and roots are also traditionally used in folklore practices for treating various ailments and diseases and research has showed the presence of antioxidant, antimicrobial, anticancer, anti-inflammatory agents present in these parts. In this study, the characterization of a bioactive compound, …

Dft Investigation Of Lewis Acid Assisted C-Cn Bond Activation Of Benzonitrile With [Ni(Dmpe)] Fragment, Lubna Kader

Theses and Dissertations

There has been recent interest in the field of organometallics with C—C bond activation of organic substrates that are mediated by transition metal complexes. The bond activation of C—C bonds is important, not only in organic synthesis but also in industrial processes. However, the activation of these bonds remains difficult since they are thermodynamically more stable and sterically less available to activate than the activation of the C—H bond. Most of the successful C—C cleavage uses the relief of ring strain, achievement of aromaticity, or proximity, as the driving force for the reaction.3 Another strategy is the use of a …

Synthesis Of Bioactive Heterocycles, Shaila Akter Shetu

Theses and Dissertations

The Discovery of a variety of heterocyclic drugs for the treatment of cancer and other diseases (e.g, neglected tropical diseases) is a medical breakthrough and inspiring for the research community as a whole. A wide range of natural, semi-synthetic, and synthetic anticancer drugs are synthesized using various methods. Among them, β -lactams stand out as a novel class of antibiotics that has different types of biological as well as anti-cancer properties. β -lactam has become a premier and active research subject towards the development of revolutionary anti-cancer drugs. In recent years, a large amount of investigations have been done to …

Recent Advances In Computational Study And Design Of Mof Catalysts For Co2 Conversion, Haoyuan Chen

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Catalytic conversion of the greenhouse gas CO2 into value-added chemicals and fuels is highly beneficial to the environment, the economy, and the global energy supply. Metal–organic frameworks (MOFs) are promising catalysts for this purpose due to their uniquely high structural and chemical tunability. In the catalyst discovery process, computational chemistry has emerged as an essential tool as it can not only aid in the interpretation of experimental observations but also provide atomistic-level insights into the catalytic mechanism. This Mini Review summarizes recent computational studies on MOF-catalyzed CO2 conversion through different types of reactions, discusses about the usage of various computational …

Saturable Absorption Of Free-Electron Laser Radiation By Graphite Near The Carbon K-Edge, Lars Hoffmann, Sasawat Jamnuch, Craig P. Schwartz, Tobias Helk, Sumana L. Raj, Hikaru Mizuno, Riccardo Mincigrucci, Laura Foglia, Emiliano Principi, Shervin Fatehi

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The interaction of intense light with matter gives rise to competing nonlinear responses that can dynamically change material properties. Prominent examples are saturable absorption (SA) and two-photon absorption (TPA), which dynamically increase and decrease the transmission of a sample depending on pulse intensity, respectively. The availability of intense soft X-ray pulses from free-electron lasers (FELs) has led to observations of SA and TPA in separate experiments, leaving open questions about the possible interplay between and relative strength of the two phenomena. Here, we systematically study both phenomena in one experiment by exposing graphite films to soft X-ray FEL pulses of …

Electrospun Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate)/Olive Leaf Extract Fiber Mesh As Prospective Bio-Based Scaffold For Wound Healing, Jose Gustavo De La Ossa, Serena Danti, Jasmine Esposito Salsano, Bahareh Azimi, Veronika Tempesti, Niccoletta Barbani, Maria Digiacomo, Marco Macchia, Mohammed Jasim Uddin, Caterina Cristallini

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Polyhydroxyalkanoates (PHAs) are a family of biopolyesters synthesized by various microorganisms. Due to their biocompatibility and biodegradation, PHAs have been proposed for biomedical applications, including tissue engineering scaffolds. Olive leaf extract (OLE) can be obtained from agri-food biowaste and is a source of polyphenols with remarkable antioxidant properties. This study aimed at incorporating OLE inside poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) fibers via electrospinning to obtain bioactive bio-based blends that are useful in wound healing. PHBHV/OLE electrospun fibers with a size of 1.29 ± 0.34 µm were obtained. Fourier transform infrared chemical analysis showed a uniform surface distribution of hydrophilic -OH groups, confirming the …

Ligand-Based Virtual Screening And Molecular Docking Of Benzimidazoles As Potential Inhibitors Of Triosephosphate Isomerase Identified New Trypanocidal Agents, Lenci K. Vazquez-Jimenez, Alfredo Juarez-Saldivar, Rogelio Gomez-Escobedo, Timoteo Delgado-Maldonado, Domingo Mendez-Alvarez, Isidro Palos, Debasish Bandyopadhyay, Carlos Gaona-Lopez, Eyra Ortiz-Perez, Benjamin Nogueda-Torres, Esther Ramirez-Moreno, Gildardo Rivera

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Trypanosoma cruzi (T. cruzi) is a parasite that affects humans and other mammals. T. cruzi depends on glycolysis as a source of adenosine triphosphate (ATP) supply, and triosephosphate isomerase (TIM) plays a key role in this metabolic pathway. This enzyme is an attractive target for the design of new trypanocidal drugs. In this study, a ligand-based virtual screening (LBVS) from the ZINC15 database using benzimidazole as a scaffold was accomplished. Later, a molecular docking on the interface of T. cruzi TIM (TcTIM) was performed and the compounds were grouped by interaction profiles. Subsequently, a selection of compounds was made based …

Excitation-Dependent Photoluminescence Of Bazro3:Eu3+ Crystals, Santosh K. Gupta, Hisham Abdou, Carlo U. Segre, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The elucidation of local structure, excitation-dependent spectroscopy, and defect engineering in lanthanide ion-doped phosphors was a focal point of research. In this work, we have studied Eu³⁺-doped BaZrO₃ (BZOE) submicron crystals that were synthesized by a molten salt method. The BZOE crystals show orange–red emission tunability under the host and dopant excitations at 279 nm and 395 nm, respectively, and the difference is determined in terms of the asymmetry ratio, Stark splitting, and intensity of the uncommon ⁵D₀ → ⁷F₀ transition. These distinct spectral features remain unaltered under different excitations for the BZOE …

Upcycling Mask Waste To Carbon Capture Sorbents: A Combined Experimental And Computational Study, Mark Robertson, Alejandro Guillen Obando, Bianca Nunez, Haoyuan Chen, Zhe Qiang

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Massive plastic pollution and grand scale emission of CO2 into the atmosphere represent two major and deeply connected societal challenges, which can have adverse impacts on climate, human health, and marine ecosystems. In particular, the COVID-19 pandemic led to substantially increased production, use, and discarding of disposable masks, a problem that requires urgent and effective technological solutions to mitigate their negative environmental impacts. Furthermore, over the years significant research efforts have sought to address the challenges of plastic waste and CO2 emission, such as development of chemical upcycling methods and low-cost CO2 capture sorbents at scale, respectively. In this work, …

Synthesis And Processing Of Polymeric Materials For Hydrogen Storage, Dominic Adrewie

Theses and Dissertations

Hydrogen is one of the most promising alternatives and clean fuel sources, but it has faced several hurdles due to storage and transportation issues. Several methods have been proposed, developed, and are being improved. Key among these is the use of polymers as safe hydrogen storage media.

This work investigated the polymerization of methyl vinyl ketone using different concentrations 2,2’-Azobis(2-methylpropionitrile) as the initiator in a free radical polymerization mechanism. There was a subsequent analysis of the effect of the initiator concentration on the conversion rate and the molecular weight of the polymers produced with the help of Gel permeation chromatography. …

Rotational Spectroscopy Of Nonafluoro-Tert-Butyl Alcohol, Zayra Leticia Gonzalez

Theses and Dissertations

Nonafluoro-tert-butyl alcohol (NFTBA) is an alcohol being used in medicine and for the analysis of physiochemical and biological properties. Quantum chemical calculations on NFTBA were carried out using cluster computers from the Texas Advanced Computing Center (TACC) at Austin, TX. We scanned the C–C–O–H dihedral angle for 36 steps with each step at 10 degrees at the B3LYP/aug-cc-pVTZ level in order to identify the stable conformations and the energy barriers. The geometry of nonafluoro-tert-butyl was studied using MP2 and B3LYP Density Functional Theory (DFT) with an aug-cc- pVTZ basis set. The calculated rotational constants and dipole moments were used to …

A Comprehensive Review On The Diverse Pharmacological Perspectives Of Terminalia Chebula Retz, Md. Rakibul Hassan Bulbul, Mohammad Nizam Uddin Chowdhury, Taslima Anjum Naima, Md. Shakil Imtiaj, Nazmul Huda, Md. Giash Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Terminalia chebula Retz, commonly known as ‘Haritaki/Myrobalan,’ has been utilised as a traditional medicine for a long time. It has been extensively exercised in various indigenous medicine practices like Unani, Tibb, Ayurveda, and Siddha to remedy human ailments such as bleeding, carminative, dysentery, liver tonic, digestive, antidiarrheal, analgesic, anthelmintic, antibacterial and helpful in skin disorders. Studies on the pharmacological effects of T. chebula and its phytoconstituents documented between January, 1996 and December, 2021 were explored using various electronic databases. During the time mentioned above, several laboratory approaches revealed the biological properties of T. chebula, including antioxidative, antiproliferative, anti-microbial, proapoptotic, …

Sar Study Of Niclosamide Derivatives In The Human Glioblastoma U-87 Mg Cells, Shizue Mito, Benxu Cheng, Benjamin A. Garcia, Daniela Gonzalez, Xin Yee Ooi, Tess C. Ruiz, Francisco Xavier Elisarraras, Andrew Tsin, Sue Anne Chew, Marco A. Arriaga

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Glioblastoma is a lethal malignant brain tumor, and the development of efficient chemotherapeutic agents remains an urgent need. Niclosamide, an anthelmintic drug, which has been used to treat tapeworm infections more than 50 years, has recently attracted renewed attention due to its evident anticancer activities. It has been shown that niclosamide induces cytotoxicity in human glioblastoma U-87 MG cells corresponding with increased protein ubiquitination, ER stress, and autophagy. Furthermore, niclosamide showed down regulation of multiple pro-survival signaling pathways including Wnt/β-catenin, PI3K/AKT, MAPK/ERK, and STAT3, which further caused reduction of U87-MG cell viability. However, the molecular mechanisms of niclosimide and its …

Investigation On The Synthesis, Application And Structural Features Of Heteroaryl 1,2-Diketones, Robert J. Wehrle, Alexander Rosen, Thu Vu Nguyen, Kalyn Koons, Eric Jump, Mason Bullard, Natalie Wehrle, Adam Stockfish, Patrick M. Hare, Abdurrahman Atesin, Tülay A. Ateşin, Lili Ma

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

A set of unsymmetrical heteroaryl 1,2-diketones were synthesized by a heteroarylation/oxidation sequence with up to 65% isolated yields. Palladium catalyst XPhos Pd G4 and SeO2 were the key reagents used in this methodology, and microwave irradiation was utilized to facilitate an efficient and ecofriendly process. The application of heteroaryl 1,2-diketones is demonstrated through the synthesis of an unsymmetrical 2-phenyl-3-(pyridin-3-yl)quinoxaline (5a) from 1-phenyl-2-(pyridin-3-yl)ethane-1,2-dione (4a). The lowest energy conformations of 4a and 5a were located using Density Functional Theory (DFT) at the M06-2X/def2-TZVP level of theory. Two lowest energy conformations of 4a differ with respect to the position of the N atom …

Multifunctional Nanomaterials For Energy Applications, Simas Rackauskas, Federico Cesano, Mohammed Jasim Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

No abstract provided.

Suppressing Disorder-Order Phase Transition Of Gd2zr2o7 Pyrochlore By Dy3+ Doping And Their Impact On Luminescence, Santosh K. Gupta, S. Nigam, Jose P. Zuniga, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The functionality of the Gd2Zr2O7 matrix is dictated by ordering at the cationic lattice (pyrochlore or defective fluorite) and associated local manifestations. In this work, we have synthesized nano and bulk undoped Gd2Zr2O7 (GZO) and Gd2Zr2O7:Dy3+ (GZOD) by molten salt synthesis adopting a crystal engineering approach and investigated their impact on photoluminescence properties. DFT calculations along with the higher intensity of yellow emission in the bulk GZOD confirm that the presence of Dy3+ is energetically favorable in defect fluorite structure compared to ordered pyrochlore counterpart. Increase/adjustments in the Zr–O bond distances in Dy3+ surroundings facilitate the release of local strain/stress …

Inorganic Cesium Lead Mixed Halide Based Perovskite Solar Materials Modified With Functional Silver Iodide, Vincent Obiozo Eze, Lucas Braga Carani, Haimanti Majumder, M. Jasim Uddin, Okenwa Okoli

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Inorganic CsPbIBr2 perovskites have recently attracted enormous attention as a viable alternative material for optoelectronic applications due to their higher efficiency, thermal stability, suitable bandgap, and proper optical absorption. However, the CsPbIBr2 perovskite films fabricated using a one-step deposition technique is usually comprised of small grain size with a large number of grain boundaries and compositional defects. In this work, silver iodide (AgI) will be incorporated as an additive into the CsPbIBr2 perovskite precursor solution to prepare the unique perovskite CsI(PbBr2)1-x(AgI)x. The AgI additive in the precursor solution works as a nucleation promoter which will help the perovskite to grow …