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Physical Sciences and Mathematics Commons

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Doctoral Dissertations

Theses/Dissertations

1994

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Full-Text Articles in Physical Sciences and Mathematics

Synthesis And Characterization Of Binuclear And Unsymmetrical Phthalocyanines, Jiang Yang Jan 1994

Synthesis And Characterization Of Binuclear And Unsymmetrical Phthalocyanines, Jiang Yang

Doctoral Dissertations

"The metal free planar binuclear phthalocyanines sharing a benzene or naphthalene ring have been synthesized and characterized. The position of Q band of binuclear phthalocyanine sharing a naphthalene ring is red shifted compared to binuclear phthalocyanine sharing a benzene ring. The compounds are shown to form the liquid crystal mesophases at room temperature.

The unique unsymmetrical phthalocyanines with steric hindrance tetraphenyl or “opposite” octaphenyl substitution have been synthesized with the aid of computer modeling. The compounds are characterized by UV-visible near IR absorption and NMR spectroscopy. Mesophase is observed by optical microscopy and differential scanning calorimetry.

The aggregation behavior has …


Production And Extraction Of Polarized Electrons From An Optically Pumped Helium Discharge, Raymond James Vandiver Jan 1994

Production And Extraction Of Polarized Electrons From An Optically Pumped Helium Discharge, Raymond James Vandiver

Doctoral Dissertations

"Polarized electron sources are needed to study the spin dependent processes in atomic and molecular systems. This area of physics has enjoyed much success in the past decade due to the development of polarized electron sources of high electron polarization and current. We have investigated the production and extraction of polarized electrons from an optically pumped helium discharge.

We have directly extracted electrons with polarizations between 6% and 7% at currents greater than 200 µA from a helium DC discharge where the helium 23S1 metastable atoms are optically pumped to nearly 100% polarization. These high metastable polarizations …