People - [ Faculty ]
Charles Pittman has a B.S. in Chemical Engineering from Lafayette College and a Ph.D. in Organic Chemistry from Pennsylvania State University. He completed postdoctoral studies with G. A. Olah, and served on active duty at the U.S. Army Solid Propulsion Laboratory. In 1967, he joined the faculty at the University of Alabama. He was appointed Full Professor in 1975 and University Research Professor in 1977.
Dr. Pittman came to Mississippi State in 1983 as Professor of Industrial Chemistry and Catalysis. He is also Research Director of the University/Industry Chemical Research Center. He has published over 750 research papers, chapters and patents; presented over 420 invited lectures; and has been supported by NSF, ARO, ONR, PRF, EPA, DOE and numerous private sources. For 10 years, he was editor of the Journal of Molecular Catalysis. He is a contributing editor to Polymer News and has been on the editorial boards of Journal of Macromolecular Science, Inorganic Chimica Acta, Reactive Polymers and Journal of Inorganic and Organometallic Polymers.
Our research has spanned the fields of organic, organometallic, polymer, inorganic chemistry, and composite materials. For example, the synthesis of organotransition metal monomers and the kinetics of their homo- and copolymerization has been an area we have pioneered. Here organic, polymer, and inorganic chemistry merge. We have been active in studying the catalysis of organic reactions using metal cluster catalysts as well as mononuclear and dinuclear organometallic complexes. We have also employed ab initio quantum mechanical calculations (HF and DFT) to a variety of organic and inorganic systems.
Investigations are carried out on the effect of ligands on rates and selectivity of these reactions, the use of asymmetric ligands to achieve asymmetric catalysis, and the photogeneration of catalytically active intermediates. In these studies organic reactions of commercial importance such as alkoxycarbonylations, hydroformylations, hydrogenations, methanol homologation, and diene oligomerizations have been studied using catalysts from the world of inorganic chemistry. Such techniques as HPLC, GC, TLC, GPC, GCMS, NMR, IR, UV polarimetry and photochemical methods are employed.
Our group was previously involved in developing new generations of electron-beam, x-ray and chemically amplified resist polymers for use in sub-micron lithography. Novel polymers, copolymers and terpolymers have been constructed; their radiation degradation behavior and sensitivity as resists studies and their thermal stabilities were characterized. Cationic polymerizations of cyclic ketene acetals and their N and S analogs are currently being examined.
Novel organic compounds such as tetrathiafulvalene (TTF) form conducting salts when reacted with such electron acceptors as tetracyanoquinodimethane (TCNQ). Organic synthetic approaches to a variety of TTF/TCNQ analogs and to their incorporation into polymers have been carried out.
The interface between homogeneous and heterogeneous catalysis was one area of our interests. For example, we have employed organic polymers and resins as supports for "normally" homogeneous organometallic catalysts. Thus, the "homogeneous" catalyst is now anchored to the polymer where it can function in a fixed polymer bed from an engineering standpoint.
Dehalogenation reactions using Ni2+- promoted alkoxyborohydrides, solvated electrons (Na/NH3 or Ca/NH3) and other strongly basic media are developed for detoxification of PCBs, CAHs and pesticides in the environment. Remediations of soils and sludges from superfund sites using Na/NH3 was studied and the Na consumption per dehalogenation event as a function of contaminant concentration and water was studied.
Research on fiberous composite materials development is focused on fiber surface functionalization followed by the designed synthesis of a polymeric elastomer interphase layer chemically bonded to the fiber. This is then chemically bound into the matrix so that a totally bonded three phase composite system is constructed. The surface analysis of treated carbon fibers and designed organic chemistry on these surfaces has been studied. Vapor grown carbon fibers in composites are currently being studied.
Nanocomposites made from polyhedral oligomeric silsesquioxanes (POSS), carbon nanofibers or nanodispersed clays are under current study. We combined small angle neutron scattering (SANS), ultrasmall angle neutron scattering (USANS) and TEM to provide the most complete description of tactoid sizes yet obtained. This shed light on the manner in which clay exfoliates. POSS, clay and nanofibers composites are being studied in thermoset matrices including cyanate esters, phenolics, epoxies, dicyclopentadiene, vinyl esters, sty/DVB and acrylic systems. Carbon nanofibers/phenolic composites were shown to have enoromous high temperature erosion resistance in plasma torch tests. POSS derivatives which chemically react with the matrix (and those which don't) have been investigated and the mechanism of phase separation into nano- and micro particles has been studied. Dispered nanophase effects on microcracking is under study. Molecular dynamics calculations on POSS-containing thermoplastics (styrenes and methacrylates) have been employed to predict Tg, moduli and a variety of other properties. Wood fiber/plastic composites which also contain nanometer-range sized particles or fibers are a recent focus of new work.
Conversion of biomass to bio-oil by fast pyrolysis is a recent, research theme. Joint with our Forest Products Laboratory, we have converted wood, sawdust, bark to bio-oil in an auger-fed reactor. Solvent fractionation of bio-oil to isolate the pyrolytic lignin-rich fraction is being studied as a wood preservative and its polymerization is being explored. With the increase in petroleum prices and the need to reduce greenhouse gas emissions, the production of fuels from biomass is becoming an increasingly important topic. If this occurs on a large scale in the future, one can predict that biorefineries will emerge from which chemical product streams will result. Thus, catalytic chemical transformations from biomass to chemicals are an interest we have.
Synthetic polymer topics under study include polymerizations of cyclic ketene acetals, olefins (Ziegler Natta Catalysis) and ring opening polymerizations. We have also studied gas phase reactions over shape-selective zeolite catalysts in a gas phase flow reactor.
Cyclic ketene-O,O (and N,O and N,S)-acetals are highly nucleophic functions combining two vinyl ether groups or a vinyl ether and an enamine moiety in the same functional group, simultaneously. We have developed a series of novel cyclizations with dielectrophiles leading to a variety of fused heterocyclic ring systems. The development of new reaction chemistry from all classes of cyclic ketene acetals is being studied.
Ab Initio quantum mechanical calculations have been employed to characterize the response surfaces of B, N, C ring and linear systems including C2H2BN, C2H2N2, B2N2 etc. POSS systems including optimized structures of the T8-, T10- and T12- cages have and are being investigated along with their endohedral complexes with metal ions (alkali, alkaline, transition metals), halides and noble gases. Alkali metal and halide exohedral complexes are also being studied. Silicon clusters SinM, where n = 10-20, containing a transition metal M and a variety of other metal clusters such as Au32, containing an endohedral Au12W, are being investigated. We have applied high level calculations to a series of [1.1.1] propellanes and their heteroatom analogs as well as substituted B2N2 four-membered ring cyclobutadiene analogs with an emphasis on studying and predicting strain.
We are also interested in the transfer of basic research into the private sector for commercial development to aid economic growth in the state of Mississippi. As research director of the University/Industry Chemical Research Center I work to bring in industrial contract research to support graduate students. This research can range from applied to fundamental basic research. The common theme is that Research Assistantships will be generated to support student positions.
Recent work on the synthesis of 5-, 6-, 7-, and 8-membered ring sulfams has been performed and library syntheses have been developed. This emphasizes the use of vinylsulfonamides and cascade reactions. New extensions to radical cascade reaction sequences on electron deficient methacrylates, methacrylamides, vinylsulfonamides are being explored.
“Arsenate adsorption on three types of granular schwertmannite,” X. Dou, D. Mohan and C.U. Pittman, Jr., submitted May 25, 2012, Water Research.
“Statistical Characterization of the Impact Strengths of Vapor-Grown Carbon Nanofiber/Vinyl Ester. Nanocomposites using a central composite Design,” G.W. Torres, S. Nouranian, T.E. Lacy, H.Toghiami, C.U. Pittman, Jr., J.L. DuBien, J. Applied Polymer Science, 2012, doi: 10.1002/APP.38190
“Synthesis of Functionalized fused-ring heterocycles from tautomers of 2-(thiazole, oxazole, benzothiazole and benzoxazole)-1-phenylethenols and 1,3-diacid chlorides and N-(chlorocabonyl) isocyamate: Synthesis of fused-ring heterocycles,” H.I. De Silva, W.P. Henry and C.U. Pittman, Jr., Synthesis, revision accepted Aug. 2012.
“Effects of Formulation, Processing and Temperature on the Viscoelastic Properties of Vapor-Grown Carbon Nanofiber/Vinyl Ester Nanocomposites,” S. Nouranian, T.E. Lacy, H. Toghiami, C.U. Pittman, Jr., J.L. DuBien, submitted J. Applied Polymer Science, July 30, 2012.
“Enantiomeric separation of racemic 4-aryl-1,4-dihyropyridines and 4-aryl-1,2,3,4-tetrahydropyrimidines on a chiral tetraproline stationary phase,” Z. Dai, C.U. Pittman, Jr. and T. Li, submitted Aug 16, 2012 Chirality.
“Enantiomeric Recognition of Racemic 4-Aryl-1,4-dihydropyridine Derivatives via Chiralpak AD-H Stationary Phases, Z. Dai, C.U. Pittman, Jr. and T. Li, Chirality 10 July 2012, doi:10.1002/chir.22083
“Reactions of keto-enol tautomers of 2-(thiazole, oxazole, benzoxazole and benzothiazole)-1-phenylethends with α,β-alkynylesters: Synthesis of highly functionized fused-ring heterocylces,” H.I. De Silva, W.P. Henry, C.U. Pittman, Jr., Synthesis, accepted, Sept. 2012.
“Selective Synthesis of Seven and Eight-membered Ring Sultams via Two Tandem Reaction Protocols from One Starting Material,” M. Wang, Y. Wang, X. Qi, G. Xia, K. Tong, J. Tu, C.U. Pittman, Jr., and A. Zhou, Organic Letters.
“Catalytic upgrading of bio-oil model compounds via olefin addition over silica sulfuric acid,” Z. Zhang, S. Sui, J. Sun, Q. Wang and C.U. Pittman, Jr., Submitted June 26, 2012, Biomass and Bioenergy.
“A coupled-cluster approach to the relative strains in [1.1.1] propellane, its derivatives and hetro [1.1.1] propellanes, H.Xu, S. Saebo, and C.U. Pittman, Jr., Molecular Physics, 1-9 (2012), doi:10.1080/00268976.2012.680517
“Versatile and Biomass Synthesis of Iron-based Nanopanticles Supported on Carbon Matrix That Has High Iron Content and Tunable Reactivity,” D. Zhang, S. Shi, C.U. Pittman, Jr., D. Jiang, W. Che, Z. Gai, J.Y. Howe, K.L. More and A. Antonyrai, Journal of Nanopanticle Research (NANO), 14, 1023-1034 (2012).
“Remediating Flouride from Water Using Hydrous Zirconium Oxide,” X. Dou, D. Mohan, C.U. Pittman Jr., and S. Yang, Chemical Eng. J., Vol. 198-199, 236-245, (2012).
“Ring Size and Sustitutent Steric Effects in Cyclic Ketene-N,O/S-acetal Trifluoroacetylations,” H.I. De Silva, Y. Song, W.P. Henry, and C.U. Pittman Jr., Tetrahedron Letters, 53, 2965-2970, (2012), doi: 10.1016/j.tetlet.2012.03.068.
“A Relative Reactivity Volume Criterion for Crosslinking: Application to Vinyl Ester Resin Dynamics Simulations,” C. Jang, T.E. Lacy, S.R. Gwaltney, H. Toghiani, and C.U. Pittman Jr., Macromolecules, 45, 4876-4885, (2012).
“Solution-Phase Synthesis and Evaluation of Tetraproline Chiral Stationary Phases,” Z. Dai, C.U. Pittman Jr., and T. Li, Chirality, 24(4), 329-338, (2012).
“Effective Property Estimates for Composites Containing Multiple Nanoheterogeneities: Part II Nanofibers and Voids,” J. Yu, T.E. Lacy, H. Toghiani, and C.U. Pittman Jr., J. Composite Materials, doi: 10:117/0021998312446824 (2012).
“Effective Property Estimates for Composites Containing Multiple Nanoheterogeneities: Part I Nanospheres, Nanoplatelets and Voids,” J. Yu, T.E. Lacy, H. Toghiani, and C.U. Pittman Jr., J. Composite Materials, published online March 27, (2012), doi: 10.1177/0021998312442557.
“Characterization of Bio-Oils Produced from Fast Pyrolysis of Corn Stalks in an Auger Reactor,” C.U. Pittman Jr., D. Mohan, A. Eseyin, L. Ingram, E.B.M. Hassan, Q. Li, B. Mitchell, H. Guo, and P.H. Steele, Energy and Fuels, 26, 3816-3825 (2012).
“A Coupled-Cluster Approach to Relative Strains in [1.1.1] Propellane, its’ Derivatives and Hetero [1.1.1] Propellanes,” H. Xu, S. Saebo, and, C.U. Pittman Jr., Molecular Physics, accepted (2012).
“Four-membered Ring Cyclic Ketene-O,O-, -O,S-, -O,N-, -S,S-, -S,N-, and -N,N- acetals and Their Corresponding Cations: A Computational Study, D.J. Beard, S.A. Barakat, N.B. Lockhart, C.R. Pace, C.U. Pittman Jr., B.W. Hamil, and, S. Saebo, Structural Chemistry, 23(8), 351-357, (2012).
“Flouride Removal from Water Using Bio-Char, a Green Waste, Low-Cost Adsorbent: Equilibrium Uptake and Sorption Dynamics Modeling,” D. Mohan, R. Sharma, V.K. Singh, P. Steele, and, C.U. Pittman Jr., Industrial and Engineering Chemistry-Research, 51(2), 900-914, (2012).
“Classical Micromechanics Modeling of Nanocomposites with Carbon Nanofibers and Interphase,” J. Yu, T.E. Lacy, H. Toghiani, and, C.U. Pittman Jr., Journal of Composite Materials, 45(23), 2401-2414, (2012).
“Molecular Dynamics Simulations of Oxidized Vapor-grown Carbon Nanofiber Surface Interactions with Vinyl Ester Resin Monomers,” C. Jang, S. Nouranian, T.C. Lacy, S.R. Gwaltney, H. Toghiani, and, C.U. Pittman Jr., Carbon, 50, 748-760, (2012).