James N. Demas

Professor, Chemistry

Primary Location

Room 144, Chemistry Building

Primary Phone Number

434.924.3343

[email protected]

Website

http://chem.virginia.edu/faculty-research/faculty/james-n-demas/

Bio & Overview

Photochemistry and Photophysics of Transition Metal Complexes Molecules excited by light lose energy by emission of light, transfer of energy or an electron to other molecules, photochemistry, and non-destructive radiationless processes. Solar energy conversion, chemical analysis, and light intensity measurements require information from the study of these processes. The processes can be highly sensitive to environmental factors such as solvent and interactions with organized media such as micelles, cyclodextrins, membranes, proteins, and DNAs. In addition, luminescence properties are very sensitive to the environment in polymer-supported sensors. We are elucidating the nature of these processes, correlating properties with molecular structure and environment, and developing new chemical, instrumental, and mathematical tools for studying these processes.

Academic Information

Department: Chemistry

Academic Title: Professor

Research Interests

Photochemistry and Photophysics of Transition Metal Complexes

Selected Publications

Xu S, Evans RE, Liu T, Zhang G, Demas JN, Trindle CO, Fraser CL, Aromatic difluoroboron β-diketonate complexes: effects of π-conjugation and media on optical properties., 2013; Inorganic chemistry. 52(7) 3597-610. PMID: 23510181 | PMCID: PMC3664511

Dixon EN, Snow MZ, Bon JL, Whitehurst AM, DeGraff BA, Trindle C, Demas JN, Environmental sensitivity of Ru(II) complexes: the role of the accessory ligands., 2012; Inorganic chemistry. 51(6) 3355-65. PMID: 22394071

Reynolds EW, Demas JN, DeGraff BA, Viscosity and temperature effects on the rate of oxygen quenching of tris-(2,2'-bipyridine)ruthenium(II)., 2012; Journal of fluorescence. 23(2) 237-41. PMID: 23108568

Payne SJ, Zhang G, Demas JN, Fraser CL, Degraff BA, Laser phosphoroscope and applications to room-temperature phosphorescence., 2011; Applied spectroscopy. 65(11) 1321-4. PMID: 22054093

Leavens BB, Trindle CO, Sabat M, Altun Z, Demas JN, DeGraff BA, Photophysical and analyte sensing properties of cyclometalated Ir(III) complexes., 2011; Journal of fluorescence. 22(1) 163-74. PMID: 21830039

Payne SJ, Fiore GL, Fraser CL, Demas JN, Luminescence oxygen sensor based on a ruthenium(II) star polymer complex., 2010; Analytical chemistry. 82(3) 917-21. PMID: 20050641

Zhang G, Kim SH, Evans RE, Kim BH, Demas JN, Fraser CL, Luminescent donor-acceptor beta-diketones: modulation of emission by solvent polarity and group II metal binding., 2009; Journal of fluorescence. 19(5) 881-9. PMID: 19399595

Fiore GL, Goguen BN, Klinkenberg JL, Payne SJ, Demas JN, Fraser CL, Ruthenium tris(bipyridine) complexes with sulfur substituents: model studies for PEG coupling., 2008; Inorganic chemistry. 47(14) 6532-40. PMID: 18563893

Ren QX, Douglass V, Xu W, Sabat M, Periasamy A, Demas JN, DeGraff BA, Potassium ion induced changes of crystal structure and fluorescence of a crown ether., 2007; Journal of fluorescence. 17(3) 249-55. PMID: 17393289

Cao W, Ferrance JP, Demas J, Landers JP, Quenching of the electrochemiluminescence of tris(2,2'-bipyridine)ruthenium(II) by ferrocene and its potential application to quantitative DNA detection., 2006; Journal of the American Chemical Society. 128(23) 7572-8. PMID: 16756313