The University of Texas at Dallas


Chemistry Program - School of Natural Sciences and Mathematics


CALDWELL, Richard A.                                                                                                       December 21, 2004

Professor of Chemistry




Born: September 28, 1940 - Huntington, W. Va.

Married Sarah Elisabeth (Betsie) Barr, November 14, 1964. Two daughters. Now  widowed.




B.Sc., Chemistry, Massachusetts Institute of Technology, 1961  Ph.D., Organic Chemistry, University of California, Berkeley, 1965 




Physical organic chemistry; photochemical mechanisms, especially intersystem crossing in photochemical intermediates,  olefin triplet and biradical chemistry, and photocycloadditions involving exciplexes. Study of nanosecond transients by  flash photolysis and time-resolved photoacoustic calorimetry. Theories of photochemical reactivity.  Computational chemistry and biology.




1964-1965      NSF Postdoctoral Fellowship, California Institute of Technology (G. S. Hammond, Supervisor)


1965-1971               Cornell University, Assistant Professor, Chemistry Department  

1971- present         The University of Texas at Dallas, Associate Professor to  Professor (from 1975) of         Chemistry


1971-1976          Acting Chairman, Chemistry Faculty; Head, Programs in Chemistry 

1977-1978          Associate Dean, School of Natural Sciences & Mathematics  

1980-1984          Dean, School of Natural Sciences & Mathematics  

1989-1991          Speaker of the University Faculty (Similar to Chairman of the Faculty Senate)  

1995-1996          Program Officer, Chemistry Division, National Science Foundation.  

1996-1997          Guest researcher NCI-SAIC, Frederick, Md. (Dr. S. K. Burt, Supervisor).

1997- 2003         Dean, School of Natural Sciences & Mathematics




National Merit Scholarship, 1957-1961 (MIT)

NSF Cooperative Fellowship, 1962-1964 (Berkeley)

NSF Postdoctoral Fellowship, 1964-1965 (Caltech)

NSF Faculty Professional Development Leave, 1978-1979 (IBM San Jose Research Labs) 

Japan Society for the Promotion of Science, Fellowship May-June 1978 (Eight Japanese universities and industrial laboratories)

Wilfred T. Doherty Award 1987


Narrative Professional Biography of Richard A. Caldwell


General.- Richard A. Caldwell received his B.S. from M.I.T. in 1961 and his Ph.D. from The University of California at  Berkeley in 1965. After a postdoctoral (1964-65) with George Hammond at Caltech he joined the faculty of Cornell University in 1965. He left in 1971 to join the faculty of the newly created (1969) University of Texas at Dallas, where he has remained ever since. A one-year (1978-79) leave on an NSF Senior Faculty Development Grant at the IBM Research Laboratories, San Jose, California, allowed him to observe and participate in the conduct of research in industry.  He spent 1995-6 as a Program Officer in the Chemistry Division of the National Science Foundation and 1996-7 as a Guest Researcher at the National Cancer Institute.  He is a member of the American Chemical Society.


Administrative and University Service.-  Dr. Caldwell served as the first Chairman/Head of Chemistry at UTD in 1971- 1976. During this time the basic planning for development of chemistry at UTD was accomplished, faculty were hired, laboratory planning and construction done, and the foundation for a long- range fruitful interaction of UTD chemistry with industry laid. He spent one year as Associate Dean of the School of Natural Sciences and Mathematics (1977-78). He was appointed Dean of the School of Natural Sciences and Mathematics in 1980. Following the establishment of an industrially oriented doctoral program in Chemistry in 1982, Dr. Caldwell resigned as Dean in 1984 to participate more directly in the development of that program and concentrate on his independent research. He has been active in University governance, having chaired the Committee on Educational Policy (1976-77) and the Committee on  Qualifications of Academic Personnel (1979-80) and served on two Search Committees for Academic Vice President  vacancies (1974, Chairman; 1992). He was elected Speaker of the University Faculty for 1989-90 and reelected for 1990-91. This position is the highest elected office in the UT-Dallas Faculty and is similar to Chairman of the Faculty Senate at other Universities. He represented UT-Dallas on the Faculty Group Advisory to the University of Texas System  in 1989-92. He served a second term as Dean in 1997-2003.


Research.- A physical organic chemist primarily studying photochemical mechanisms, he has centered his work on the  observation of reactive intermediates and determination of their chemical and physical properties. He is best known for establishing the involvement of exciplexes as obligatory intermediates in photochemical reactions (Accts. Chem. Res., 1980, 13, 45). More recently his work has emphasized (1) transient spectroscopy and theoretical studies of olefin triplets and triplet biradicals with the goal of understanding the factors which cause intersystem crossing; (2) studies of reactivity in singlet and triplet state photocycloadditions with the goal of understanding the fundamental origins of such photoreactivity; (3) studies of highly strained and therefore transient ground state species such as trans-cyclohexenes  and -heptenes. The first mentioned project was supported by NSF from 1980-1999 (FY98 budget $105,000 TC) and the second by the Robert A. Welch Foundation (FY00 budget $45,000 TC). The third is supported in different aspects by  each of the two. Time-resolved photoacoustic calorimetry and transient-transient chemistry following laser excitation are promising recent ventures. Total C&G support for his research since 1965 has been approximately $2,340,000, about 65% from NSF with most of the rest from the Welch  Foundation.  Dr. Caldwell spent 1996-7 at the Frederick (Md.) Biomedical Supercomputing Center, NCI-SAIC to learn computational biology and computational techniques for studying solvent-solute interactions. The last mentioned topics comprise his major current research efforts.


Professional Service.-  Dr. Caldwell was Chairman of the 1993 Gordon Conference on Organic Photochemistry. He has been Vice-President (1992-1994) and President (1994-1996) of the Inter-American Photochemical Society and served on many of its committees.  He was a member (1980-5) and Chairman (1983-5) of  the Advisory Committee of the Center for Fast Kinetics Research at The University of Texas at Austin. He has served on the Steering Committee of the U. S.-Japan Cooperative  Photoconversion and Photosynthesis Program. He was Chairman of the XVII IUPAC Symposium on Photochemistry, held in Barcelona, Spain, in July 1998. He was the Osprey Lecturer at the University of Cincinnati in October 1999.


Honors. - He received the 1987 Wilfred T. Doherty Award, sponsored by the Dallas-Fort Worth section of the American Chemical Society and given to a member annually to recognize contributions to chemistry.







1. "Metalation of Norbornadiene with Butyllithium", with A. Streitwieser, Jr., J. Org. Chem.1962, 27, 3360.  


2. "Activation Parameters for Exchange of Toluene-a-D with Lithium Cyclohexylamide in Cyclohexylamine", with A.  Streitwieser, Jr., M. R. Granger, and P. M. Laughton, J. Phys. Chem. 1964, 68, 2916.  


3. "Relative Stabilities of Triphenylmethyl and Bridgehead Triptycyl Carbanions", with A. Streitwieser, Jr., and M. R.  Granger, J. Am. Chem. Soc. 1964, 86, 3578.


4. "Kinetics and Mechanism of Exchange of Benzene and sec-Butylbenzene with Cesium Cyclohexylamide", with A.  Streitwieser, Jr., J. Am. Chem. Soc. 1965, 87, 5394.


5.  "Comparison of Relative Proton Exchange Rates of Hydrocarbons with Lithium Cyclohexylamide and Cesium  Cyclohexylamide", with A. Streitwieser, Jr., R. G. Lawler, and G. R. Ziegler, J. Am. Chem. Soc. 1965, 87, 5399.  


6. "Triplet States in Radiation Chemistry. Radiochemical Cis-trans- Isomerization", with D. G. Whitten and G. S. Hammond,  J. Am. Chem. Soc. 1966, 88, 2659.


7. "Secondary Deuterium Isotope Effects on the Transfer of Triplet Electronic Excitation to an Olefin", with G. Wayne  Sovocool, J. Am. Chem. Soc. 1968, 90, 7138.


8. "Correlation between Photochemistry and High-Energy Radiation Chemistry", with G. S. Hammond, John M. King, H.  Kristinsson, and D. G. Whitten, Photochem. Photobiol., 1968, 7, 695.  


9. "Photosensitized Fragmentation of a Bicyclo (4.2.0)-octa-2,4-diene Derivative. Preparation of the Isomeric 1,2- Diacetoxyethylenes", J. Org. Chem.,1969, 34, 1886.


10. "The Cesium Cyclohexylamide Catalyzed Proton Exchange of Cyclohexane with Cyclohexylamine", with A. Streitweiser  and W. R. Young, J. Am. Chem. Soc. 1969, 91, 527.


11. "Kinetic Acidities of Small Ring Cycloalkanes and Correlation with J(13C- H)", with A. Streitwieser, Jr., and W. R. Young,  J. Am. Chem. Soc. 1969, 91, 529.


12. "Quenching of Fluorenone Fluorescence by Triethylamine. Medium Effects on the Singlet Lifetime", Tetrahedron Lett.,  1969, 2121.


13. "Norrish II Fragmentation of 3, 4-Diphenylbutyrophenone. Loss of Spin Memory in a 1, 4-Biradical", with Peter M. Fink,  Tetrahedron Lett., 1969, 2987.


14. "Secondary Isotope Effects as Photochemical Mechanistic Criteria. Photosensitized cis-trans Olefin Isomerization not  Involving the Olefin Triplet State", with Stephen P. James, J. Am. Chem. Soc., 1969, 91, 5184.  


15. "Quantitative Deuteration of a Grignard Reagent. The Preparation of 2- Butene-2-d", J. Org. Chem., 1970, 35, 1193.  


16. "Isotope and Substituent Effects on the Interaction of Benzophenone Triplets with Simple Olefins. Apparent Insufficiency  of the Schenk Mechanism", J. Am. Chem. Soc., 1970, 92, 1439.  


17. "Isoprene Triplets as Excitation Donors. Non-vertical De-excitation", J. Am. Chem. Soc., 1970, 92, 3229.  


18. "The Fluorenone-sensitized Photoisomerization of trans-Stilbene. Inefficiencies both in Intersystem Crossing and in  Triplet Excitation Transfer", with R. P. Gajewski, J. Am. Chem. Soc., 1971, 93, 532.  


19. "Secondary Deuterium Isotope Effects on Triplet Excitation Transfer. Deuterium Position and Sensitizer Effects", with G.  W. Sovocool and R. J. Peresie, J. Am. Chem. Soc., 1971, 93, 779.  


20. "Quenching of Excited States by Stable Free Radicals. The Effect of Di-t- Butyl Nitroxide on Stilbene and Naphthalene  Triplets", with R. E. Schwerzel, J. Am. Chem. Soc., 1972, 94, 1035.  


21. "Quenching of Excited States by Stable Free Radicals. II. On the Mechanism of Triplet Quenching of Di-tert-butyl  Nitroxide", with Robert E. Schwerzel, J. Am. Chem. Soc., 1973, 95, 1382.  


22. "Secondary Deuterium Isotope Effects on the Transfer of Triplet Excitation", with G. W. Sovocool and R. J. Peresie, J. Am. Chem. Soc., 1973, 95, 1496.


23. "Intermediates and Stereochemistry in the Triplet-State Photocycloaddition of Phenanthrene to Electron-Poor Olefins", J. Am. Chem. Soc., 1973, 95, 1690.


24. "The Primary Interaction Between Diaryl Ketone Triplets and Simple Alkenes", with G. W. Sovocool and R. P. Gajewski,  J. Am. Chem. Soc., 1973, 95, 2549.


25. "The Photocycloaddition of 9-Cyanophenanthrene to Substituted b-Methylstyrenes. An Obligatory Exciplex Intermediate",  with L. Smith, J. Am. Chem. Soc., 1974, 96, 2994.


26. "Role of a Singlet Exciplex in the Photocycloaddition of Phenanthrene to Dimethyl Fumarate", with D. Creed, J. Am. Chem. Soc., 1974, 96, 7369.


27. "Exciplex Quenching. Geometric and Electronic Requirements", with D. Creed and H. Ohta, J. Am. Chem. Soc., 1975,  97, 3246.


28. "Thermodynamics of Exciplex Formation by Time-Resolved Nanosecond Flash Spectroscopy", with D. Creed, Paul H.  Wine, and Lynn A. Melton, J. Am. Chem. Soc., 1976, 98, 621.  


29.  "Exciplex Substitution (Sex). A New Photophysical Process", with H. Ohta, D. Creed, P. Wine, and L. A. Melton, J. Am. Chem. Soc., 1976, 98, 2002.


30. "Exciplex Quenching. A Frontier Molecular Orbital Rationale", with D. Creed, H. Ohta, and D. DeMarco, J. Am. Chem. Soc., 1977, 99, 277.


31. "The Delphi Project: A Study of Attitudes toward Undergraduate Education in Chemistry", with L. A. Melton, C. A. Parr,  and A. D. Sherry, J. Chem. Ed., 1977, 54, 640.


32. "Electrochemical and Electrogenerated Chemiluminescence Studies of Substituted Olefin- Cyanophenanthrene Mixed  Systems", with Su-Moon Park, J. Electrochem. Soc., 1977, 124, 1859.  


33.  "Interception of a Triplet Biradical by Paramagnetic Species. Enhancement of a Photocycloaddition", with David Creed,  J. Am. Chem. Soc., 1977, 99, 8360.


34. "Photocycloaddition of b-Methylstyrenes to Some 9-Cyanophenanthrenes. Chemical Consequences of Exciplex  Formation", with Nabih I. Ghali, C.-K. Chien, D. DeMarco, and Larry Smith, J. Am. Chem. Soc., 1978, 100, 2857.  


35. "Temperature and Substituent Dependence of Photocycloadditions Involving Exciplexes", with D. Creed, J. Am. Chem. Soc., 1978, 100, 2905.


36. "Triplet Sensitization and Exciplex Quenching of the Photochemical Reaction between Phenanthrene and Dimethyl  Fumarate", with D. Creed, and (in part) Mary McKenney Ulrich, J. Am. Chem. Soc., 1978, 100, 5831.  


37. "The Effects of Oxygen and di-t-Butyl Nitroxide on the Photoreaction of Phenanthrene with Dimethyl Fumarate", with D.  Creed, J. Phys. Chem., 1978, 82, 2644.


38.  "Polar Substituent Effects in Triplet Quenching. Excitation Transfer and Cycloaddition", with D. Creed and T.-S. Maw, J. Am. Chem. Soc., 1979, 101, 1293.


39. "An Olefin Triplet Lifetime Measurement by Electron Transfer Interception", with C. Pac, Chem. Phys. Lett., 1979, 64,  303.


40. "The Effect of Multiplicity on Regiochemistry of [2+2] Photocycloaddition of 3,9-Dicyanophenanthrene to trans-b- Methylstyrene", with T.-S. Maw, J. Photochem., 1979, 11, 165.  


41. "Activation Parameters in the Photocycloaddition of Phenanthrene to Dimethyl Fumarate", with D. Creed, J. Am. Chem. Soc., 1979, 101, 6960.


42. "Charge Transfer Quenching of Singlet Excited Complexes", with D. Creed, L. A. Melton, D. C. DeMarco, H. Ohta, and  P. H. Wine, J. Am. Chem. Soc., 1980, 102, 2369.


43. "Exciplex Intermediates in [2+2] Photocycloadditions", with D. Creed, Accts. Chem. Res., 1980, 13, 45.  


44. "A Predictor of Reactivity in Allowed Photodimerizations and Photocycloadditions", J. Am. Chem. Soc., 1980, 102, 4004.  


45.  "Lifetimes of Some Styrene Triplets in Fluid Solution. Triplet Geometries and the Effects of Alkylation", with Chi Van  Cao, J. Am. Chem. Soc., 1981, 103, 3594.


46. "Photochemistry of the Phenanthrene - Stilbene System. Cycloaddition and Singlet-Sensitized Isomerization", with K.  Mizuno, P. E. Hansen, L. P. Vo, M. Frentrup, and C. D. Ho, J. Am. Chem. Soc., 1981, 103, 7263.  


47. "Some Structural Effects on Triplet Biradical Lifetimes. Norrish II and Paterno-Buchi Biradicals", with T. Majima and C.  Pac, J. Am. Chem. Soc., 1982, 104, 629.


48. "Structural Effects on Twisted Olefin Triplet Lifetimes. Styrene Derivatives", with C. V. Cao, J. Am. Chem. Soc., 1982,  104, 6174.


49. "Lifetimes of Conjugated Diene Triplets", with M. Singh, J. Am. Chem. Soc., 1982, 104, 6121.  


50. "Conformations and Competitive [2+2] Cycloadditions of Intramolecular Exciplexes of Some Anisylalkenyl 9- Phenanthrenecarboxylates", with H. Sakuragi, K. Tokumaru, H. Itoh, K. Terakawa, K. Kikuchi, and C-C. Hsu, J. Am. Chem. Soc., 1982, 104, 6796.


51. "The Effect of Polar Substituent on Olefin Triplet Lifetime", with M. Singh, J. Am. Chem. Soc., 1983, 105, 5139.  


52. "Direct Observation and Chemistry of l,6 Biradicals in the Norrish I Reaction", with H. Sakuragi and T. Majima, J. Am. Chem. Soc., 1984, 106, 2471.


53. "Intersystem Crossing in Organic Photochemical Intermediates", Pure and Applied Chemistry, 1984, 56, 1167-1177.  


54. "The Lifetime of a Conformationally Constrained Norrish II Biradical. Photochemistry of cis-1-Benzoyl-2- benzhydrylcyclohexane", with S. N. Dhawan and T. Majima, J. Am. Chem. Soc., 1984, 106, 6454.  


55. "Photochemical Electron Transfer Reactions and Exciplexes", with D. Creed, Photochem. Photobiol., 1985, 41, 715.  


56. "pH Dependence of the Lifetime of a Norrish II Biradical", with S. N. Dhawan and D. E. Moore, J. Am. Chem. Soc., 1985,  107, 5163.


57. "Direct Observation of a 1,3 Biradical", with K. Mizuno, N. Ichinose, and Y. Otsuji, J. Am. Chem. Soc., 1985, 107, 5797.


58. "Use of Pulsed Time-Resolved Photoacoustic Calorimetry to Determine the Strain Energy of trans-1-Phenylcyclohexene  and the Energy of the Relaxed 1-Phenylcyclohexene Triplet", with J. L. Goodman, K. S. Peters, and H. Misawa, J. Am. Chem. Soc., 1986, 108, 6803.


59. "Photochemistry of 4,4-Dimethyl-1-mesityl-2-pentyn-1-one", with W. C. Agosta, J. Jay, L. J. Johnston, V. B. Rao, J. C.  Scaiano, M. Singh, and S. Wolff, J. Am. Chem. Soc., 1987, 109, 3050.  


60. "An Unusually Large Secondary Deuterium Isotope Effect. Thermal trans-cis Isomerization of trans-1- Phenylcyclohexene", with H. Misawa, E. F. Healy, and M. J. S. Dewar, J. Am. Chem. Soc., 1987, 109, 6869.  


61. "Viable Geometries for T1-S0 ISC in Alkene Triplets", with L. Carlacci, C. E. Doubleday, Jr., T. R. Furlani, H. F. King, and  J. W. McIver, Jr., J. Am. Chem. Soc., 1988, 110, 6901.


62. "The Relaxed and Spectroscopic Energies of Olefin Triplets," with Ni Tuqiang and L. A. Melton, J. Am. Chem. Soc.,  1989, 111, 457-464.


63. "Absence of Conformational Dependence of Norrish II Biradical Lifetimes," with S. C. Gupta, J. Am. Chem. Soc., 1989, 111, 740-742.


64.  "Laser Flash Photolysis Studies of Intersystem Crossing in Biradicals and Alkene Triplets;" in: Platz, M., Ed.; "Kinetics  and Spectroscopy of Carbenes and Biradicals; " Plenum Publishing: New York;  1990; pp 77-116. (Invited).


65. "Benzoquinone-Olefin Exciplexes: the Observation and Chemistry ot the p-Benzoquinone-Tetraphenylallene Exciplex,"  with K. R. Schnapp, R. M. Wilson, D. M. Ho, and D. Creed, J. Am. Chem. Soc., 1990, 112, 3700-3702. 


66.  "Photochemical and Photophysical Behavior of p-Methoxyphenylalkenyl Phenanthrenecarboxylates. 1. Structure and  Competitive Formation of Intramolecular Cycloaddition Products," with H. Sakuragi, K. Tokumaru, H. Itoh, K. Terakawa,  K. Kikuchi, and C. C. Hsu, Bull. Chem. Soc. Jpn., 1990, 63, 1049-1057.  


67. "Photochemical and Photophysical Behavior of p-Methoxyphenylalkenyl Phenanthrenecarboxylates. 2. Kinetic  Investigation of Intramolecular Cycloaddition ," with H. Sakuragi, K. Tokumaru, H. Itoh, K. Terakawa, K. Kikuchi, and C.  C. Hsu, Bull. Chem. Soc. Jpn., 1990, 63, 1058-1061. 


68. "Determination of Triplet Excitation Energies of Cyclic Enones by Time-Resolved Photoacoustic Calorimetry," with D. I.  Schuster, G. E. Heibel, and Wei Tang, Photochem. Photobiol., 1990, 52, 645-648.  


69. "Photoacoustic Calorimetry of Cycloheptene Derivatives. Relaxed Triplet Energies of 1-Phenylcycloheptene and 1,3- Cycloheptadiene and the Energetics of Ground-State cis-trans Isomerisation,"  with Colin M. Brennan, Photochem. Photobiol.,  1991, 53, 165-170.


70. "Nanosecond Kinetic Absorption and Calorimetric Studies of Cyclopentenone: the Triplet, Self-Quenching, and the   Predimerization Biradicals," with  Wei Tang, D. I. Schuster, and  G. E. Heibel, Photochem. Photobiol., 1991, 53, 159-164.  


71.  "Conformationally Dependent Heavy Atom Effect of Chlorine on Alkene Triplet Lifetimes. Experiment and Ab Initio  Calculations", with L. D. Jacobs, T. R. Furlani, E. A. Nalley, and J. Laboy, J. Am. Chem. Soc., 1992, 114, 1623-1625.  


72. "The Heat of Formation of the Benzophenone Ketyl Radical by Time-Resolved Photoacoustic Calorimetry," with L. G.  Arnaut, J. Photochem. Photobiol. A., 1992, 65, 15-20.


73.  "Relaxed Triplet Energies of Phenylnorbornenes. The Role of Phenyl-Vinyl Torsions. On the Origin of Nonvertical  Excitation Transfer," with S. J. Riley, A. A. Gorman, and D. J. Unett, J. Am. Chem. Soc., 1992, 114, 4224-4226.  


74. "Recent Advances in Photoacoustic Calorimetry: Improvements in Experimental Design," with L. G. Arnaut, J. E. Elbert,  and L. A. Melton, Rev. Sci. Instrum., 1992, 63, 5381-5389.  


75. "Stereospecific Photocycloaddition of Electron-Deficient Arylalkenes to 9-Cyanophenanthrene via an Exciplex," with K.  Mizuno, A. Tachibana. and Y. Otsuji, Tetrahedron Lett., 1992, 33, 5779-5782.  


76. "Potential Energy Surfaces of a one-way isomerizing olefin studied by photoacoustic calorimetry and X-ray  crystallography," with T. Arai, H. Okamoto, K. Tokumaru, T. Ni, and K. Ueno, J. Photochem. Photobiol. A: Chem., 1993,  75, 85-90.


77. "Thermochemistry of Strained Cycloalkenes: Experimental and Computational Studies," with A. D. Strickland, J. Phys. Chem., 1993, 97, 13394-13402.


78. "Are Perpendicular Alkene Triplets Just 1,2-Biradicals?  Studies with the Cyclopropylcarbinyl Clock,"  with  Lingwen Zhou.  J. Am. Chem. Soc., 1994, 116, 2271-2275.


79. "Nonvertical Triplet Excitation Transfer to Arylalkene Acceptors:  Further Evidence That Double Bond Torsion is  Unimportant,"  with C. M. Brennan, J. E. Elbert, and D. J. Unett,  J. Am. Chem. Soc., 1994, 116, 3460-3464.  


80. "Alkane Triplets as 1,2-Biradicals:  The Photoaddition of p-Acetylstyrene to Styrene,"  with J. Felipe Diaz, Duane  C. Hrncir, and David J. Unett,  J. Am. Chem. Soc., 1994, 116, 8138-8145.  


81. "Singlet State Cis,Trans Photoisomerization and Intersystem Crossing of 1-Arylpropenes,"  with Frederick D.  Lewis, Dario M. Bassani, and David J. Unett,  J. Am. Chem. Soc., 1994, 116, 10477-10485. 


82. "Triplet Species from Norbornadiene.  Time Resolved Photoacoustic Calorimetry and ab initio Studies of Energy,  Geometry, and Spin - Orbit Coupling,"  with Anna M. Helms, J. Am. Chem. Soc., 1995, 117, 358-361.  


83. "The Triplet State of Alkenes:  Structure, Dynamics, Energetics and Chemistry,"  with D. J. Unett,  Res. Chem.  Intermed., 1995, 21, 665-709.


84.  "Photodimerization of 1-Phenylcyclohexene.  A Novel Transient - Transient Component,"  with David J. Unett  and Duane C. Hrncir, J. Am. Chem. Soc.,1996, 118, 1682-1689.   


85. "Photocycloaddition of 4,4-Dimethylcyclohexenone to 1,1-Diphenylethylene.  Evidence for a Triplet Exciplex Intermediate," with Duane C. Hrncir, T. Mu–oz, and David J. Unett, J. Am. Chem. Soc., 1996, 118, 8741-8742.


86. "Triplet Energy and Lifetime of 2,3-Diazabicyclo[2.2.2]oct-1-ene," with Anna M. Helms, Paul S. Engel, and A. Wu, J. Phys. Chem., 1996, 100, 17716-17717.


87. "Time-Resolved Photoacoustic Calorimetry of Tri- and Tetraphenylethylenes. Do S0 and T1 Energy Surfaces Cross?" with D. J. Unett and J. J. Vipond, Photochem. Photobiol., 1997, 65, 530-534.


88. "Enthalpies of Hydrogenation and of Formation of 1-Phenylcycloalkenes," with Joel F. Liebman, Donald W. Rodgers, and David J. Unett, Journal of Molecular Structure, 1997, 413-414, 575-578.


89. ÒSite Selectivity in [2+2]Photocycloadditions of 2H, 8H-Benzo[1,2-b:3,4-bÕ]dipyran-2,8-dione to Alkenes,Ó with J. Bethke, P. Margaretha, and A. M. Wynne,  Journal of Chemical Research(S), 1998,


90. "Photochemical  C-C Bond Cleavage of 1,2-Diarylcyclopropanes Bearing an Acetylphenyl Group. Generation and  Observation of Triplet 1,3-Biradicals," with N. Ichinose, K. Mizuno, A. Helms, and Y. Otsuji, J. Org. Chem.,1998, 63, 3176-3184.


91. ÒCalculation of the Aqueous Solvation Free Energy of the Proton,Ó with Gregory J. Tawa, Igor Topol, A. Rashin, and S. K. Burt, J. Chem. Phys, 1998, 109, 4852-4863.


92. ÒStereospecific (2p+2p) photocycloaddition of arylalkenes to pyrene via exciplex: formation of 1:1- and 2:1-cycloadductsÓ    with K. Mizuno, H.  Maeda,  Y. Inoue,  A. Sugimoto, and L. P. Vo, Tetrahedron Lett., 2000,  41(25),  4913-4916.


93. ÒAcidity of Organic Molecules in the Gas Phase and in Aqueous Solvent,Ó with I. A. Topol, G. J. Tawa,  M. A. Eissenstat, and S. K. Burt,Ó J. Phys. Chem. A, 2000, 104, 9619-9624.


94. ÒPhotoannulation of 4,4-Dimethylcyclohex-2-en-1-one To 1,1-Diphenylethylene,Ó with Ralf Constien and Bryan G. Kriel, Journal of Physical Chemistry A , 2003, 107(18),  3277-3286.