Jared A. Butcher

A novel infrared spectrometer using a linear array detector

An infrared spectrometer has been constructed that employs a 32-element InSb linear array detector. A comparison has been made of the spectra obtained with this spectrometer with those obtained with a Fourier transform infrared spectrometer. It has been predicted that, from 2400 to 2650 cm−1 in the infrared spectrum, a four-microsecond transient could be captured with an approximate SNR of 50.

CHEMILUMINESCENCE FROM CARBENE OXIDATION

Abstract— The chemiluminescent reaction between carbenes and O2 in Freon 113 at and above 77 K was investigated. The reaction was found to be general for phenylated carbenes and independent of precursor. Spectra obtained by optical multichannel analyzer (OMA) are consistent with the emission being from the excited ketone formed. Kinetics studies at 77 K indicate that the decay of the chemi‐luminescence is significantly faster than the decay of the carbene as monitored by fluorescence and electron paramagnetic resonance.

Analysis of plastic recycling products by expert systems

Abstract An automated method for monitoring a polyethylene recycling process has been developed. The products of catalyzed polyethylene cracking are alkanes, monounsaturated alkenes (monoene) and dienes, which were analyzed by gas chromatog-raphy-mass spectrometry. Three expert systems, a knowledge based expert system, a univariate rule building expert system and a fuzzy multivariate expert system, were developed and evaluated for their ability to correctly classify products of polyethylene cracking by their degree of unsaturation. Two test sets were used in the evaluation. One contained spectra from a mass spectral library. The second was a collected set of hydrocarbon standards. On both test sets, the rule building expert systems performed better than the knowledge based expert system. The chemometric detectors were effective for mathematically resolving chromatograms by chemical functionality.

Application of laser photolysis to the study of reactive intermediates

Excimer laser flash photolysis in the study of diphenyl carbene (DPC) reveals the presence of at least three transient species produced by excitation of a precursor at 249 nm in isooctane solution at room temperature depending on the concentration of O2present. In an aerated solution, a fast first-order decay assigned to3DPC leads to the formation of an unassigned species which also decays by first order kinetics to produce the observed product Ph2CO. In degassed solution, the fast first-order decay of a species to produce3DPC which decays by second-order kinetics to produce the dimeric products observed.

Macrocyclic ring formation in micelles

The influenae SDS micelles exert on the course of the chemical reaction initiated by excimer laser photolysis of long-chain bis-dibenzylsulfone detergent molecules is evaluated. In the presence of SDS [2.12]3-paracyclophane forms, in the absence of SDS it does not.