Scott S. Fielder

Bis(2,2′-bipyridine)(1,2-diimino-9,10-anthraquinone)ruthenium(II): a complex containing an exceptionally strong π-accepting α-α′ diimine ligand I. Synthesis, crystal and electronic structures

Abstract The compound 1,2-diamino-9,10-anthraquinone (DAAQ) binds to ruthenium bis-(2,2′-bipyridine) forming a complex containing the oxidized 1,2-diimino-9,10-anthraquinone (DIAQ). The complex was crystallized as [Ru(bpy)2DIAQ](1,3-benzenedisulfonate)·6.5H2O. Crystal data: triclinic, space group P1−, a = 10.095(2) A , b = 12.035(2) A , c = 17.652(4) A , α = 97.50(3)°, β = 92.54(3)°, γ = 91.65(3)° , Z = 2 . The metal is bound to the diimine site of the DIAQ ligand. There is an extensive n backbonding interaction between the DIAQ ligand and the metal as inferred from theoretical calculations, electrochemical and spectroscopic data. The DIAQ is the best a accepting neutral α-α′ diimine ligand known to date.

Atmospheric Photochemistry of Naphthalene: a Practical and Theoretical Approach

Abstract The reaction of naphthalene with the OH radical was studied in a 10 m3 smog chamber. Reaction products identified include 1,2-benzenedicarboxaldehyde, phthalic anhydride, phthalic acid, 1(3H)-isobenzofuranone, 1,4-naphthalenedione, 4-methyl-2H-1-benzopyran-2-one, 1-naphthol, 2-naphthol, 1-nitronaphthalene, 2-formylcinnamic acid, 2-nitronaphthalene, 4-nitro-1-naphthol, 2-nitro-1-naphthol, 1,4-naphthoquinone-2,3-epoxide, 2,4-dinitro-1-naphthol and 3-nitrophthalic anhydride. The presence of 2-formylcinnamic acid has been suggested by combined gas chromatography/mass spectrometry and its formation has been investigated and modeled via self consistent field, ab initio, Graphic Electronic Structures Molecular Modeling (GESMM).

An Overview of the First Stable Products and their Short-Lived Intermediate Precursors in the OH-Naphthalene Reactant System in the Environment of a Photochemical Smog Chamber

Abstract A study has been carried out which utilizes an FMO-Mapping model to qualitatively and partially identify the thermodynamic pathways that map out the first stable products and their precursors in the evolution of the OH-naphthalene reactant system under the conditions existing in a 10 m3 smog chamber. During the course of this study, the modeling suggested that singlet molecular oxygen could be a potential competitor of the OH radical for reaction with the naphthalene. This family of reactants has been produced in a laboratory environment that addresses one particular aspect of real-world, atmospheric chemistry. The simplification of real world PAH chemistry has been attempted by using naphthalene as a surrogate that is expected to be widely reflective of many aspects of the behavior of the much wider family of PAH.

A pulse sequencer and transient nanoammeter system for membrane voltage‐dependent capacitance measurements

A highly sensitive system for producing and time‐resolving small‐signal current transients in bilayer lipid membranes separating two ionic solutions is described. The circuitry can be constructed from inexpensive and readily obtainable electronic components, and may be interfaced with a variety of digital oscilloscopes or data acquisition systems. The system consists of a driver, fast nanoammeter, and timing sequencer. The driver is capable of delivering a stable, very low impedance voltage pulse (−2.0 to +2.0 V) superimposed on a clamping voltage adjustable within the same range. The pulse can be of any width between 500 μs and 5000 s, and can be delayed with respect to an oscilloscope synchronization trigger, which is also provided. The nanoammeter is accurate between 10 pA and 100 mA and has a time resolution of better than 10 μs. The driver and nanoammeter were designed specifically to be stable under the conditions of a highly capacitive load with very high dc resistance, as is typical of a bilayer lipid membrane. The system can be used with either reference or blocking electrodes. Ideal and actual membrane transient response curves, along with noise assessment data, are provided for calibration purposes.