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9 results on '"Ra, Doyoung"'

1. Comparison of excited-state energy transfer in arrays of hydroporphyrins (chlorins, oxochlorins) versus porphyrins: Rates, mechanisms, and design criteria

Author

Taniguchi, Masahiko, Diers, James R., Ra, Doyoung, Knox, Robert S., Kirmaier, Christine, Bocian, David F., Hindin, Eve, Lindsey, Jonathan S., Schwartz, Jennifer K., and Holten, Dewey

Subjects
Porphyrins -- Chemical properties, Porphyrins -- Research, Raman spectroscopy -- Research, Absorption -- Research, Chemistry
Abstract

A set of hydroporphyrins, which consists of chlorin-chlorin and oxochlorin-oxochlorin are prepared with components in the same or different metalation states and studied using static and time-resolved absorption and emission spectroscopy, resonance Raman spectroscopy and electrochemical techniques. Further, a comparison between the excited-state energy transfer in arrays of hydroporphyrins and porphyrins is conducted.

Published
2003

2. Synthesis and electronic properties of regioisomerically pure oxochlorins

Author

Taniguchi, Masahiko, Kim, Han-Je, Ra, Doyoung, Schwartz, Jennifer K., Kirmaier, Christine, Hindin, Eve, Diers, James R., Prathapan, Sreedharan, Bocian, David F., Holten, Dewey, and Lindsey, Jonathan S.

Subjects
Chemistry, Organic -- Research, Oxo compounds, Chlorine compounds, Zinc compounds, Ring formation (Chemistry) -- Research, Biological sciences, Chemistry
Abstract

Research has been conducted on the C-alkylated zinc chlorins. The two-step conversion of these compounds to zinc oxochlorins with the keto group located in the macrocycle's reduced ring has been carried out and the details are described.

Published
2002

3. Synthesis of meso-substituted chlorins via tetrahydrobilene-a intermediates

Author

Taniguchi, Masahiko, Ra, Doyoung, Mo, Guoning, Balasubramanian, Thiagarajan, and Lindsey, Jonathan S.

Subjects
Chemistry, Organic -- Research, Chlorine compounds -- Physiological aspects, Photochemical research -- Analysis, Metals -- Physiological aspects, Biological sciences, Chemistry
Abstract

Research has been conducted on the chlorin building blocks which incorporate a geminal dimethyl group in the reduced ring. The preparation of these building blocks has been carried out in a facile and rational manner and the results are described.

Published
2001

4. Introduction of a third meso substituent into 5,10-diaryl chlorins and oxochlorins

Author

Taniguchi, Masahiko, Kim, Man Nyoung, Ra, Doyoung, and Lindsey, Jonathan S.

Subjects
Deuterium -- Chemical properties, Pyrrole -- Chemical properties, Chlorine compounds -- Research, Biological sciences, Chemistry
Abstract

The treatment of a 5,10-diaryl-substituted chlorin or oxychlorin with TFA-d1 resulted in selective deuteration of the remaining meso positions rather than any of the beta-pyrrolic positions. This study provides access to new chlorine or oxochlorins that can be utilized in diverse applications.

Published
2005

5. Progress towards synthetic chlorins with graded polarity, conjugatable substituents, and wavelength tunability

Author

Ra, Doyoung, primary, Gauger, Kelly A., additional, Muthukumaran, Kannan, additional, Balasubramanian, Thiagarajan, additional, Chandrashaker, Vanampally, additional, Taniguchi, Masahiko, additional, Yu, Zhanqian, additional, Talley, Daniel C., additional, Ehudin, Melanie, additional, Ptaszek, Marcin, additional, and Lindsey, Jonathan S., additional

Published
2015
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7. MASS SPECTROMETRIC STUDIES OF 3-SUBSTITUTED-5-AMINO-1,3,4- THIADIAZOLIN-2-ONES

Author

Lee, UnChul, Lee, Won, Kim, YunJe, Park, SongJa, Ra, DoYoung, and Cho, NamSook

Abstract

AbstractFragment pathways of 3-alkyl and acyl-5-amino-1,3,4-thiadiazolin-2-ones were completely assigned by mass analyzed kinetic energy spectra (MIKE), collisional activated dissociation (CAD) spectra and high resolution mass spectra. [NH2CS]+and [S=C═O]+ions were directly formed from molecular ion of the 3-alkyl compounds and from 5-amino-3H-1,3,4-thiadiazolin-2-one ion (1) which was produced by McLafferty rearrangement from molecular ion of 3-acyl compounds. A loss of neutral SCO was only detected from 3-alkyl substituted molecular ions.

Published
1997
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8. MASS SPECTROMETRIC STUDIES OF 3-SUBSTITUTED-5-AMINO-1,3,4-THIADIAZOLIN-2-ONES

Author

Lee, UnChul, Lee, Won, Kim, YunJe, Park, SongJa, Ra, DoYoung, and Cho, NamSook

Abstract

AbstractFragment pathways of 3-alkyl and acyl-5-amino-1,3,4-thiadiazolin-2-ones were completely assigned by mass analyzed kinetic energy spectra (MIKE), collisional activated dissociation (CAD) spectra and high resolution mass spectra. [NH2CS]+and [S˭C˭O]+ions were directly formed from molecular ion of the 3-alkyl compounds and from 5-amino-3H−1,3,4 -thiadiazolin-2-one ion (1) which was produced by McLafferty rearrangement from molecular ion of 3-acyl compounds. A loss of neutral SCO was only detected from 3-alkyl substituted molecular ions.

Published
1998
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9. Novel Calix[4]arene Azacrown Ether

Author

Kim, JongSeung, Yu, IllYong, Suh, IlHwan, Ra, DoYoung, and Kim, JongWan

Abstract

Abstract1,3-diproyloxycalix[4]arene azacrown ether was successfully synthesized in the fixed 1,3-alternate conformation which was confirmed by a solid state structure.

Published
1998
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