Regents Professor Franklin Professor Biography Michael A. Duncan was born in Greenville, SC, and attended Furman University. He received his Ph.D. (1982) at Rice University with Prof. Richard Smalley. He held an NRC Postdoctoral Fellowship at the Joint Institute for Laboratory Astrophysics (Boulder, CO) with Prof. Stephen Leone. He joined the University of Georgia faculty in 1983, and is now Franklin Professor and Regents' Professor. He is a Fellow of the American Physical Society, the American Association for the Advancement of Science and the American Chemical Society. He is an Alexander von Humboldt Senior Fellow. He was Senior Editor for the Journal of Physical Chemistry for the period of 1998-2015, and Chair of the Physical Division of the American Chemical Society in 2019. Education Education: B.S. Chemistry, Furman University, 1976. Ph.D. Physical Chemistry, Rice University, 1982. Research Research Areas: Physical Chemistry Computational/Theoretical Chemistry Inorganic Chemistry Research Interests: Our research program uses lasers, electrical discharges and pulsed supersonic molecular beams to produce a variety of unusual molecules, ions, metal complexes and atomic or molecular clusters. The extreme conditions of the "synthesis" processes employed make it possible to produce strange molecular aggregates including metal atom nanoclusters, novel organometallic complexes (metal benzene sandwiches, metal-fullerenes), metal ions "solvated" by 1-30 water molecules, proton-bound dimers, carbon clusters, or carbocations. These systems test fundamental concepts of chemical bonding and provide models for metal-metal or metal-ligand bonding, metal ion solvation and metal-adsorbate interactions, and additionally provide specific examples of proton-transfer or organic reaction intermediates as well as interstellar molecules. The ions or clusters produced are detected and size-selected with a specially-designed time-of-flight mass spectrometer and studied with UV-visible or infrared laser spectroscopy. Computational chemistry methods are employed to complement the experimental work. The combined spectroscopy measurements and computational work provides definitive answers about molecular structure, electronic structure, bonding energetics and the reactivity of these systems. Selected Publications Selected Publications: J. E. Colley, A. G. Batchelor, M. A. Duncan, "Cation-π Bonding in Actinides: UOx+(Benzene) (x = 0,1,2) Complexes Studied with Threshold Photodissociation Spectroscopy and Theory," J. Phys. Chem. Lett. 16, 1515−1521 (2025). DOI: 10.1021/acs.jpclett.4c03603. A. G. Batchelor, J. H. Marks, T. B. Ward, M. A. Duncan, "Co+(C2H2)n Complexes Studied with Infrared Photodissociation Spectroscopy and Theory," J. Phys. Chem. A128, 8954−8963 (2024). DOI: 10.1021/acs.jpca.4c05304. J. E. Colley, N. J. Dynak, J. R. C. Blais, M. A. Duncan, "Photodissociation Spectroscopy and Photofragment Imaging of the Mg+(Benzene) Complex," J. Phys. Chem. A 128, 10507-10515 (2024). DOI: 10.1021/acs.jpca.4c05703. J. E. Colley, N. J. Dynak, J. R. C. Blais, M. A. Duncan, "Photodissociation Spectroscopy and Photofragment Imaging to Probe the Dissociation Energy of the Fe+(Acetylene) Complex," J. Phys. Chem. A 127, 1244‒1251 (2023). DOI: 10.1021/acs.jpca.2c08456. J. E. Colley, N. J. Dynak, J. R. C. Blais, M. A. Duncan, "Photodissociation Spectroscopy and Photofragment Imaging to Probe the Dissociation Energies of the Fe+(Benzene)1,2 Complexes," J. Phys. Chem. A 127, 2795‒2804 (2023). DOI: 10.1021/acs.jpca.3c00735. Erratum: J. Phys. Chem. A 128, 5224−5224 (2024). DOI: 10.1021/acs.jpca.4c03633. J. E. Colley, D. S. Orr, M. A. Duncan, "Charge-Transfer Spectroscopy of Ag+(Benzene) and Ag+(Toluene)," J. Phys. Chem. A 127, 4822–4831 (2023). DOI: 10.1021/acs.jpca.3c01790. A. G. Batchelor, J. H. Marks, T. B. Ward, M. A. Duncan, "Pt+(C2H2)n Complexes Studied with Infrared Photodissociation Spectroscopy," J. Phys. Chem. A 127, 5704−5712 (2023). DOI: 10.1021/acs.jpca.3c02734. A. D. Brathwaite, J. H. Marks, I. J. Webster, A. G. Batchelor, T. B. Ward, M. A. Duncan, "Coordination and Spin States in Fe+(C2H2)n Complexes Studied with Infrared Spectroscopy," J. Phys. Chem. A 126, 9680‒9690 (2022). DOI: 10.1021/acs.jpca.2c07556. B. M. Rittgers, J. H. Marks, D. J. Kellar, M. A. Duncan, "Photoinduced Charge Transfer in the Zn-Methanol Cation Studied with Selected-Ion Photofragment Imaging," J. Chem. Phys. 157, 114302 (2022). DOI: 10.1063/5.0108467. J. E. Colley, D. S. Orr, M. A. Duncan, "Electronic Transition of l-C6+ at 417 nm," J. Chem. Phys. 157, 121102 (2022). DOI: 10.1063/5.0106183. N. J. Dynak, B. M. Rittgers, J. E. Colley, D. J. Kellar, M. A. Duncan, "Photofragment Imaging of Carbon Cluster Cations: Explosive Ring Rupture," J. Phys. Chem. Lett. 13, 4786−4793 (2022). DOI: 10.1021/acs.jpclett.2c00950. A. B. McCoy, M. A. Duncan, "Spectral Signatures of Anharmonicity in the Vibrational Spectrum of Protonated Ethylene," J. Molec. Spec. 389, 111704 (2022). DOI: 10.1016/j.jms.2022.111704. J. H. Marks, E. Miliordos, M. A. Duncan, "Infrared Spectroscopy of RG-Co+(H2O) Complexes (RG = Ar, Ne, He): The Role of Rare Gas "Tag" Atoms," J. Chem. Phys. 154, 064306 (2021). DOI: 10.1063/5.0041069. J. H. Marks, B. M. Rittgers, M. J. van Stipdonk, M. A. Duncan, "Photodissociation and Infrared Spectroscopy of Uranium-Nitrogen Cation Complexes," J. Phys. Chem. A 125, 7278−7288 (2021). (Dan Neumark Festschrift). DOI: 10.1021/acs.jpca.1c05823. J. P. Wagner, D. C. McDonald, P. R. Franke, M. A. Duncan, "Infrared Spectroscopy of the Protonated HCl Dimer and Trimer," J. Chem. Phys. 155, 134302 (2021). DOI: 10.1063/5.0065477. I. J. Webster, J. L. Beckham, N. D. Johnson, M. A. Duncan, "Photochemical Synthesis and Spectroscopy of Covalent PAH Dimers," J. Phys. Chem. A 126, 1144-1157 (2022). DOI: 10.1021/acs.jpca.1c10606. M. A. Boyer, C. S. Chiu, D. C. McDonald II, J. P. Wagner, J. E. Colley, D. S. Orr, M. A. Duncan, A. B. McCoy, "The Role of Tunneling in the Spectra of H5+ and D5+ up to 7300 cm-1," J. Phys. Chem. A 124, 4427–4439 (2020). DOI: 10.1021/acs.jpca.0c02299. P. D. Carnegie, J. H. Marks, A. D. Brathwaite, T. B. Ward, M. A. Duncan, "Microsolvation in V+(H2O)n Clusters Studied with Selected-Ion Infrared Spectroscopy," J. Phys. Chem. A 124, 1093−1103 (2020). DOI: 10.1021/acs.jpca.9b11275. J. H. Marks, T. B. Ward, A. D. Brathwaite, S. Ferguson, M. A. Duncan, "Cyclotrimerization of Acetylene in Gas Phase V+(C2H2)n Complexes: Detection of Intermediates and Products with Infrared Spectroscopy," J. Phys. Chem. A 123, 6733-6743 (2019). DOI: 10.1021/acs.jpca.9b04962. M. P. Woodard, M. A. Duncan, "Laser Synthesis and Spectroscopy of Molybdenum Oxide Nanorods," J. Phys. Chem. C 123, 9560-9566 (2019). DOI: 10.1021/acs.jpcc.9b00627. D. C. McDonald II, J. P. Wagner, A. B. McCoy, M. A. Duncan, "Near-Infrared Spectroscopy and Anharmonic Theory of Protonated Water Clusters: Higher Elevations in the Hydrogen Bonding Landscape," J. Phys. Chem. Lett.9, 5664–5671 (2018). DOI: 10.1021/acs.jpclett.8b02499. J. P. Wagner, D. C. McDonald II, M. A. Duncan, "Mid-Infrared Spectroscopy of C7H7+ Isomers in the Gas Phase: Benzylium and Tropylium," J. Phys. Chem. Lett. 9, 4591–4595 (2018). DOI: 10.1021/acs.jpclett.8b02121. J. P. Wagner, D. C. McDonald II, M. A. Duncan, "An Argon-Oxygen Covalent Bond in the ArOH+ Molecular Ion," Angew. Chem. Int. Ed. 57, 5081-5085 (2018). (communication) DOI: 10.1002/anie.201802093. D. T. Mauney, J. A. Maner, M. A. Duncan, "IR Spectroscopy of Protonated Acetylacetone and its Water Clusters: Enol-Keto Tautomers and Ion → Solvent Proton Transfer," J. Phys. Chem. A 121, 7059-7069 (2017). DOI: 10.1021/acs.jpca.7b07180. T. B. Ward, E. Miliordos, P. D. Carnegie, S. S. Xantheas, M. A. Duncan, "Ortho-Para Interconversion in Cation-Water Complexes: The Case of V+(H2O) and Nb+(H2O) Clusters," J. Chem. Phys.146, 224305 (2017). DOI: 10.1063/1.4984826. D. C. McDonald, D. T. Mauney, D. Leicht, J. H. Marks, J. A. Tan, J.-L. Kuo, M. A. Duncan, "Communication: Trapping a Proton in Argon: Spectroscopy and Theory of the Proton-Bound Argon Dimer and its Solvation," J. Chem. Phys. 145, 231101 (2016). DOI: 10.1063/1.4972581. D. T. Mauney, J. D. Mosley, L. R. Madison, A. B. McCoy, M. A. Duncan, "Infrared Spectroscopy and Theory of Formaldehyde Cation and its Hydroxymethylene Isomer," J. Chem. Phys. 145, 174303 (2016). DOI: 10.1063/1.4966214. J. A. Maner, D. T. Mauney, M. A. Duncan, "Imaging Charge Transfer in a Cation-π System: Velocity-Map Imaging of Ag+(Benzene) Photodissociation," J. Phys. Chem. Lett. 6, 4493−4498 (2015). DOI: 10.1021/acs.jpclett.5b02240. A. D. Brathwaite, T. B. Ward, R. S. Walters, M. A. Duncan, "Cation-π and CH-π Interactions in the Coordination and Solvation of Cu+(Acetylene)n Complexes," J. Phys. Chem. A 119, 5658–5667 (2015). DOI:10.1021/acs.jpca.5b03360. J. D. Mosley, J. W. Young, M. A. Duncan, "Infrared Spectroscopy of the Acetyl Cation and Its Protonated Ketene Isomer," J. Chem. Phys. 141, 024306 (2014). DOI: 10.1063/1.4887074. A. M. Ricks, A. D. Brathwaite, M. A. Duncan, "IR Spectroscopy of V+(CO2)n Clusters: Solvation-Induced Electron Transfer and Activation of CO2," J. Phys. Chem. A 117, 11490–11498 (2013). DOI: 10.1021/jp4089035. M. A. Duncan, "Infrared Laser Spectroscopy of Mass-Selected Carbocations," J. Phys. Chem. A 116, 11477–11491 (2012) (invited Feature Article). DOI: 10.1021/jp309037d. T. C. Cheng, B. Bandyopadhyay, J. D. Mosley, M. A. Duncan, "IR Spectroscopy of Protonation in Water-Benzene Nanoclusters: Hydronium, Zundel and Eigen at a Hydrophobic Interface," J. Am. Chem. Soc. 134, 13046−13055 (2012). DOI:10.1021/ja3038245. J. D. Mosley, T. C. Cheng, A. B. McCoy, M. A. Duncan, "Infrared Spectroscopy of the Mass 31 Cation: Protonated Formaldehyde vs Methoxy," J. Phys. Chem. A 116, 9287–9294 (2012). DOI:10.1021/jp3072298. A. M. Ricks, L. Gagliardi, M. A. Duncan, "Oxides and Superoxides of Uranium Detected by IR Spectroscopy in the Gas Phase," J. Phys. Chem. Lett. 2, 1662-1666 (2011). DOI: 10.1021/jz2006868. A. M. Ricks, Z. E. Reed, M. A. Duncan, "IR Spectroscopy of Gas Phase Metal Carbonyl Cations," J. Mol. Spec. 266, 63-74 (2011) (invited feature article; cover art). DOI: 10.1016/j.jms.2011.03.006. A. M. Ricks, L. Gagliardi, M. A. Duncan, "Infrared Spectroscopy of Extreme Coordination: The Carbonyls of U+ and UO2+," J. Am. Chem. Soc. 132, 15,905-15,907 (2010). DOI: 10.1021/ja1077365. T. C. Cheng, B. Bandyopadhyay, Y. Wang, S. Carter, B. J. Braams, J. M. Bowman, M. A. Duncan, "The Shared Proton Mode Lights Up the Infrared Spectrum of Fluxional Cations H5+ and D5+," J. Phys. Chem. Lett. 1, 758-762 (2010). DOI: 10.1021/jz100048v. G. E. Douberly, R. S. Walters, J. Cai, K. D. Jordan, M. A. Duncan, "Infrared Spectroscopy of Small Protonated Water Clusters H+(H2O)n (n = 2-5): Isomers, Argon Tagging and Deuteration," J. Phys. Chem. A 114, 4570-4579 (2010). DOI: 10.1021/jp100778s. A. M. Ricks, G. E. Douberly, P. v. R. Schleyer, M. A. Duncan, "The Infrared Spectrum of Gas Phase C3H3+: The Cyclopropenyl and Propargyl Cations," J. Chem. Phys. 132, 051101 (2010). DOI: 10.1063/1.3298881. A. M. Ricks, G. E. Douberly, M. A. Duncan, "The Infrared Spectroscopy of Protonated Naphthalene and Its Relevance for the Unidentified Infrared Bands," Astrophys. J. 702, 301-306 (2009). DOI: 10.1088/0004-637X/702/1/301. A. M. Ricks, Z. D. Reed, M. A. Duncan, "Seven-Coordinate Homoleptic Metal Carbonyls in the Gas Phase," J. Am. Chem. Soc. 131, 9176-9177 (2009). DOI: 10.1021/ja903983u. M. A. Duncan, "Structures, Energetics and Spectroscopy of Gas Phase Transition Metal Ion-Benzene Complexes," Int. J. Mass Spectrom. 272, 99-118 (2008). DOI:10.1016/j.ijms.2008.01.010. G. E. Douberly, A. M. Ricks, B. W. Ticknor, P. v. R. Schleyer, M. A. Duncan, "Infrared Spectroscopy of Gas Phase Benzenium Ions: Protonated Benzene and Protonated Toluene from 750 to 3400 cm-1," J. Phys. Chem. A 112, 4869-4874 (2008). DOI: 10.1021/jp802020n G. E. Douberly, A. M. Ricks, P. v. R. Schleyer, M. A. Duncan, "Infrared Spectroscopy of Gas Phase C3H5+: The Allyl and 2-Propenyl Cations," J. Chem. Phys. 128, 021102 (2008). DOI: 10.1063/1.2828553. L. Belau, S. E. Wheeler, B. W. Ticknor, M. Ahmed, S. R. Leone, W. D. Allen, H. F. Schaefer, M. A. Duncan, "Ionization Thresholds of Small Carbon Clusters: Tunable VUV Experiments and Theory," J. Am. Chem. Soc.129, 10229-10243 (2007). DOI: 10.1021/ja072526q. J. B. Jaeger, T. D Jaeger, M. A. Duncan, "Photodissociation of Metal-Silicon Clusters: Encapsulated versus Surface-Bound Metal," J. Phys. Chem. A 110, 9310-9314 (2006). DOI: 10.1021/jp0629947. J. Headrick, E. G. Diken, R. S. Walters, N. I. Hammer, R. A. Christie, J. Cui, E. M. Myshakin, M. A. Duncan, M. A. Johnson, K. D. Jordan, "Spectral Signatures of Hydrated Proton Vibrations in Water Clusters," Science 308, 1765-1769 (2005). DOI: 10.1126/science.1113094. T. D. Jaeger, D. van Heijnsbergen, S. Klippenstein, G. von Helden, G. Meijer, M. A. Duncan, "Vibrational Spectroscopy and Density Functional Theory of Transition Metal Ion-Benzene and Dibenzene Complexes," J. Am. Chem. Soc. 126, 10981-10991 (2004). DOI: 10.1021/ja0477165. J.-W. Shin, N. I. Hammer, E. G. Diken, M. A. Johnson, R. S. Walters, T. D. Jaeger, M. A. Duncan, R. A. Christie, K. D. Jordan, "Infrared Signature of Structural Motifs Associated with the H+(H2O)n, n = 6-27, Clusters," Science 304, 1137-1140 (2004). DOI: 10.1126/science.1096466. M. A. Duncan "Infrared Spectroscopy to Probe Structure and Dynamics in Metal Ion-Molecule Complexes," Int. Rev. Phys. Chem. 22, 407-435 (2003). DOI: 10.1080/0144235031000095201. G. A. Grieves, J. W. Buchanan, J. E. Reddic, M. A. Duncan, "Photodissociation of Exohedral Transition Metal-C60 Complexes," Int. J. Mass Spectrom.204, 223-232 (2001). DOI: 10.1016/S1387-3806(00)00362-6. M. A. Duncan, "Frontiers in the Spectroscopy of Mass-Selected Molecular Ions," Int. J. of Mass Spectrom. 200, 545-569 (2000). DOI: 10.1016/S1387-3806(00)00366-3. G. von Helden, A. G. G. M. Tielens, D. van Heijnsbergen, M. A. Duncan, S. Hony, L. B. F. M. Waters, G. Meijer, "Titanium Carbide Nanocrystals in Circumstellar Environments," Science 288, 313-316 (2000). DOI: 10.1126/science.288.5464.313. D. van Heijnsbergen, G. von Helden, M. A. Duncan, A. J. A. van Roij, G. Meijer, "Vibrational Spectroscopy of Gas Phase Metal Carbide Clusters and Nanocrystals," Phys. Rev. Lett. 83, 4983-4983 (1999). DOI: 10.1103/PhysRevLett.83.4983. J. W. Buchanan, G. A. Grieves, J. E. Reddic, M. A. Duncan, "Novel Mixed-Ligand Sandwich Complexes: Competitive Binding of Iron with Benzene, Coronene and C60," Int. J. Mass Spectrom. 182, 323-333 (1999). DOI: 10.1016/S1387-3806(98)14239-2. J. W. Buchanan, J. E. Reddic, G. A. Grieves, M. A. Duncan, "Metal and Multi-Metal Complexes with Polyaromatic Hydrocarbons: Formation and Photodissociation of Fex-(Coronene)y Cations," J. Phys. Chem. A 102, 6390-6394 (1998). DOI: 10.1021/jp981513j. M. A. Duncan, "Spectroscopy of Metal Ion Complexes: Gas Phase Models for Solvation," Annu. Rev. Phys. Chem. 48, 69-93 (1997). DOI: 10.1146/annurev.physchem.48.1.69. C. S. Yeh, J. S. Pilgrim, D. L. Robbins, K. F. Willey, M. A. Duncan, "Spectroscopy of Weakly-Bound Magnesium Ion Complexes," Int. Rev. Phys. Chem.13, 231-262 (1994). DOI: 10.1080/01442359409353295. J. S. Pilgrim, M. A. Duncan, "Beyond Metallo-Carbohedrenes: Growth and Decomposition of Metal-Carbon Nanocrystals," J. Am. Chem. Soc.115, 9724-9727 (1993). DOI:10.1021/ja00074a044. A. M. Rao, P. Zhou, K. A. Wang, G. T. Hager, J. M. Holden, Y. Wang, W. T. Lee, X. X. Bi, P. C. Eklund, D. S. Cornett, M. A. Duncan, I. J. Amster, "Photo-Induced Polymerization of Solid C60 Films," Science 259, 955-957 (1993). DOI: 10.1126/science.259.5097.955. K. F. Willey, C. S. Yeh, D. L. Robbins, M. A. Duncan, "Charge Transfer in the Photodissociation of Metal Ion-Benzene Complexes," J. Phys. Chem. 96, 9106-9111 (1992). DOI: 10.1021/j100202a007. K. F. Willey, C. S. Yeh, D. L. Robbins, J. S. Pilgrim, M. A. Duncan, "Photodissociation Spectroscopy of Mg+-H2O and Mg+-D2O," J. Chem. Phys. 97, 8886-8895 (1992). DOI: 10.1063/1.463363. K. F. Willey, P. Y. Cheng, M. B. Bishop, M. A. Duncan, "Charge Transfer Photochemistry in Ion-Molecule Cluster Complexes of Silver," J. Am. Chem. Soc. 113, 4721-4728 (1991). DOI: 10.1021/ja00013a001. M. A. Duncan and D. A. Rouvray, "Microclusters," Scientific American 161, 110-115 (1989). K. LaiHing, R. G. Wheeler, W. L. Wilson, M. A. Duncan, "Photoionization Dynamics and Abundance Patterns in Laser Vaporized Tin and Lead Clusters," J. Chem. Phys. 87, 3401-3409 (1987). DOI: 10.1063/1.452984. T. G. Dietz, M. A. Duncan, D. E. Powers, R. E. Smalley, "Laser Production of Supersonic Metal Cluster Beams," J. Chem. Phys. 74, 6511-6512 (1981). DOI: 10.1063/1.440991. M. A. Duncan, T. G. Dietz, M. G. Liverman, R. E. Smalley, "Two-Color Photoionization of Naphthalene and Benzene at Threshold," J. Chem. Phys. 75, 2118-2125 (1981). DOI: 10.1063/1.442315. Of note: Fellow of the American Physical Society Fellow of the American Association for the Advancement of Science Fellow of the American Chemical Society Alexander von Humboldt Senior Fellow Courses Regularly Taught: CHEM 3211 CHEM 8960 CHEM 8940
