Will E. Lynch

A square-planar hydrated cationic tetrakis(methimazole)gold(III) complex

The cationic pseudo-square-planar complex tetrakis(1-methyl-2,3-dihydro-1H-imidazole-2-thione-κS)gold(III) trichloride sesquihydrate, [Au(C4H6N2S)4]Cl3·1.5H2O, was isolated as dark-red crystals from the reaction of chloroauric acid trihydrate (HAuCl4·3H2O) with four equivalents of methimazole in methanol. The Au(III) atoms reside at the corners of the unit cell on an inversion center and are bound by the S atoms of four methimazole ligands in a planar arrangement, with S-Au-S bond angles of approximately 90°.

Manganese(II) chloride complexes with pyridine N-oxide (PNO) derivatives and their solid-state structures

The synthesis and structures of three manganese(II) pyridine N-oxide complexes are presented.

Crystal structure of 2,6-di-chloro-4-nitro-pyridine N-oxide.

In the title compound, C5H2Cl2N2O3, the nitro group is essentially coplanar with the aromatic ring, with a twist angle of 4.00 (6)° and a fold angle of 2.28 (17)°. The crystal structure exhibits a herringbone pattern with the zigzag running along the b axis. The herringbone layer-to-layer distance is 3.0075 (15) Å, with a shift of 5.150 (4) Å. Neighboring molecules are tilted at a 57.83 (4)° (ring-to-ring) angle with each other. The nitro group on one molecule points to the N-oxide group on the neighboring one, with an intermolecular O⋯N(nitro) distance of 3.1725 (13) Å.

Preparation and Spectroscopic Characterization of MoS2 and MoSe2 Nanoparticles

Abstract In this manuscript, we report an experiment for the upper division chemistry laboratory involving the synthesis and characterization of molybdenum (IV) chalcogenide nanoparticles. The reaction is a straightforward synthesis between molybdenum hexacarbonyl and sulfur or selenium. Students follow the progress of the reaction via monitoring the carbonyl stretch using Fourier transform infrared (FTIR) spectroscopy. The nanoparticles are found to absorb light in the UV region of the spectrum compared with the near IR for bulk molybdenum (IV) chalcogenides. Further, the particles also exhibit a blue fluorescence when excited in the UV region. Students can easily complete the experiment in two 3‐hr laboratory periods, one focusing on the synthesis and the other on the spectroscopic characterization.

Synthesis, stereochemical characterization, and antimicrobial evaluation of a potentially nonnephrotoxic 3′-C-acethydrazide puromycin analog

GRAPHICAL ABSTRACT ABSTRACT Puromycin is a peptidyl nucleoside endowed with significant antibiotic and anticancer properties, but also with an unfortunate nephrotoxic character that has hampered its use as a chemotherapeutic agent. Since hydrolysis of puromycins amide to puromycin aminonucleoside is the first metabolic step leading to nephrotoxicity, we designed a 3′-C-hydrazide analog where the nitrogen and carbon functionality around the amide carbonyl of puromycin are inverted. The title compound, synthesized in 11 steps from D-xylose, cannot be metabolized to the nephrotoxic aminonucleoside. Evaluation of the title compound on Staphylococcus epidermidis and multi-drug resistance Staphylococcus aureus did not show significant antimicrobial activity up to a 400 μM concentration.

Crystal structure of 3-bromo­pyridine N-oxide

In the title compound, C5H4BrNO, there are two molecules in the asymmetric unit that are related by a pseudo-inversion center. The two independent molecules are approximately planar, with an observed (ring–ring) angle of 5.49 (13)°. The crystal structure exhibits a herringbone pattern with the zigzag running along the b-axis direction. The least-squares plane containing the rings of both asymmetric molecules and the plane containing the symmetrically related molecules make a plane–plane angle of 66.69 (10)°, which makes the bend of the herringbone pattern. The bromo group on one molecule points to the bromo group on the neighboring molecule, with a Br⋯Br intermolecular distance of 4.0408 (16) Å. The herringbone layer-to-layer distance is 3.431 (4) Å with a shift of 1.742 (7) Å. There are no short contacts, hydrogen bonds, or π–π interactions.

Infusion of Nanotechnology in Chemistry Courses Through Laboratory Redesign and Vertical Threads

Chemistry occupies a unique place in the university curriculum and is required by a wide variety of other disciplines because of its general utility. Unfortunately, the laboratory portion of the course does not always reflect the diversity and excitement of new research in and interesting applications of chemistry since the laboratory experience is designed to help the student master fundamental concepts. At Armstrong Atlantic State University (AASU) we are attacking this problem with the implementation of two series of nanotechnology based “vertical threads” throughout our chemistry curriculum. The vertical threads begin in the freshman year and provide continuity throughout the rest of the curriculum. Experiments direct the students attention towards modern applications of chemical technology while providing chemical fundamentals expected in traditional laboratory exercises. By seeing these recurring threads at ever increasing levels of complexity, students build upon knowledge gained about nanotechnology with each additional laboratory course. The approach used at AASU created two experimental “vertical threads” which are woven into the educational experience from the bottom-up in both the curriculum and the chemical methodology. Experiments performed in the freshman chemistry lab reappear in expanded forms in subsequent years as part of new experiments that mimic the biological, industrial and medical applications of nanotechnology. We have concentrated our efforts in two areas: magnetite nanoparticles thread, and the chalcogenide nanoparticles thread. Magnetite nanoparticles are prepared by freshmen students while more advanced students modify these nanoparticles for real-world applications. Chalcogenide nanoparticles are synthesized by junior and senior level students and their spectroscopic properties are studied. Senior and undergraduate research students are involved in green synthesis of silver and gold nanoparticles as well as the use of ZnS, CdS and ceria nanoparticles for photocatalysis applications. The upper division students learn numerous instrumental techniques (i.e. UV-VIS, Fluorescence, FT-IR) within the context of nanotechnology. All students are presented with pre-laboratory and background materials that address the needs for new materials, new techniques for biomedical analysis and drug delivery as well as the environmental impacts of nanotechnology.