Joseph S. Francisco

Purdue University, ウェストラファイエット, Indiana, United States

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Publications (512)1859.74 Total impact

  • Lei Li · Manoj Kumar · Chongqin Zhu · Jie Zhong · Joseph S. Francisco · Xiao Cheng Zeng
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    ABSTRACT: In the atmosphere, a well-known and conventional pathway towards the formation of ammonium sulfate is through the neutralization of sulfuric acid with ammonia (NH3) in water droplets. Here, we present direct ab initio molecular dynamics (AIMD) simulation evidence of the formation of ammonium bisulfate (NH4HSO4) from the hydrated NH3 and SO3 molecules in a water trimer as well as on the surface of a water droplet. This reaction suggests a new mechanism for the formation of ammonium sulfate in the atmosphere, especially when the concentration of NH3 is high (e.g., ~10 μg m-3) in the air. Contrary to the water monomer and dimer, the water trimer enables near-barrierless proton transfer via the formation of a unique loop structure around the reaction center. The formation of the loop structure promotes the splitting of a water molecule in the proton-transfer center, resulting in the generation a NH_4^+/HSO_4^- ion pair. The loop-structure promoted proton transfer mechanism is expected to be ubiquitous on the surface of cloud droplets with adsorbed NH3 and SO3 molecules, and thus, may play an important role in the nucleation of aerosol particles (e.g, fine particles PM2.5) in water droplets.
    No preview · Article · Jan 2016 · Journal of the American Chemical Society
  • Joseph S Francisco · Manoj Kumar
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    ABSTRACT: The role of metal free dual catalysis in the hydrogen sulfide (H2S)-induced activation of carbon dioxide (CO2) and subsequent decomposition of resulting monothiol carbonic acid has been explored. The results suggest that monofunctional amines and bifunctional acids via dual activation mechanisms promote both activation and decomposition reactions implying that the judicious selection of a dual catalyst is crucial to the efficient C-S bond formation via CO2 activation. Considering that our results also suggest a new mechanism for the formation of carbonyl sulfide from CO2 and H2S, these new insights may help in better understanding the coupling between the carbon and sulfur cycles in industry as well as in the atmosphere of Earth and Venus.
    No preview · Article · Jan 2016 · Chemistry - A European Journal
  • Kan Luo · Yingjie Qiao · Shihong He · Xian-Hu Zha · Qing Huang · Jian He · Cheng-Te Lin · Joseph S. Francisco · Shiyu Du
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    ABSTRACT: First-principles calculations are performed in this work to study the effects of M(M=Mg, Sr, Ba, La) substitution in CaB6. Both electronic structure and mechanical properties are examined. The current results indicate that the substitution of Ca by M atoms causes the lattice constants to scale linearly with the variation of x. The shear moduli of MxCa1−xB6 are found to be related to the valence d-electron Mulliken charges in the lattice. The hardnesses of M(M=Mg, Ca, Sr, Ba, La)B6 and their solid solution are calculated by analyzing the overlap populations of the B–B bonds in the solid solution system.
    No preview · Article · Jan 2016 · Ceramics International
  • Zhuang Wu · Dingqing Li · Hongmin Li · Bifeng Zhu · Hailong Sun · Joseph S Francisco · Xiaoqing Zeng
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    ABSTRACT: The dipolar oxathiazyne-like sulfinylnitrene RS(O)N, a highly reactive α-oxo nitrene, has been rarely investigated. Upon flash vacuum pyrolysis of sulfinyl azide CF3 S(O)N3 at 350 °C, an elusive sulfinylnitrene CF3 S(O)N was generated in the gas phase in its singlet ground state and was characterized by matrix-isolation IR spectroscopy. Further fragmentation of CF3 S(O)N at 600 °C produced CF3 and a novel iminyl radical OSN, an SO2 analogue, which were unambiguously identified by IR spectroscopy. Consistent with the experimental observations, DFT calculations clearly support a stepwise decomposition mechanism of CF3 S(O)N3 .
    No preview · Article · Dec 2015 · Angewandte Chemie International Edition
  • Ryan C. Fortenberry · Joseph S. Francisco
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    ABSTRACT: The SNO− and OSN− anions are shown in this work to be very stable negatively charged species in line with other recent work [T. Trabelsi et al., J. Chem. Phys. 143, 164301 (2015)]. Utilizing established quartic force field techniques, the structural and rovibrational data for these anions are produced. The SNO− anion is less linear and has weaker bonds than the corresponding neutral radical giving much smaller rotational constants. OSN− is largely unchanged in these regards with inclusion of the additional electron. The S–N bond is actually stronger, and the rotational constants of OSN− versus OSN are similar. The vibrational frequencies of SNO− are red-shifted from the radical while those in OSN− are mixed. OSN− has mixing of the stretching modes while the S–N and N–S stretches of SNO− are largely independent of one another. The ω 3 stretches are much brighter in these anions than they are in the radicals, but the ω 1 stretches are still the brightest.
    No preview · Article · Nov 2015 · The Journal of Chemical Physics
  • Manoj Kumar · Joseph S Francisco
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    ABSTRACT: The gas-phase decomposition of the α-hydroxy methylperoxy radical has been theoretically examined, and the results provide insight into a new source of the hydroperoxy radical (HO2 ) in the troposphere. Bimolecular peroxy decomposition is promoted by the red-light or near-IR radiation excitation. The calculations suggest for the first time, an important chemical role for the H2 O⋅HO2 radical complex that exist in significant abundance in the troposphere. In particular, the reaction of organic peroxy radicals with the HO2 radical and the H2 O⋅HO2 radical complex represent an autocatalytic source of atmospheric HO2 . This reaction is a new example of red-light-initiated atmospheric chemistry that may help in understanding the discrepancy between the observed and measured levels of the HOx at sunrise.
    No preview · Article · Nov 2015 · Angewandte Chemie International Edition
  • Source
    Chasity B Love-Nkansah · Lei Tan · Joseph S Francisco · Yu Xia
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    ABSTRACT: Homocysteine sulfinyl radical ((SO⋅) Hcy) is a reactive intermediate involved during oxidative damage of DNA in the presence of high concentrations of homocysteine (Hcy). The short lifetime of (SO⋅) Hcy makes its preparation, isolation, and characterization challenging using traditional chemical measurement tools. Herein, we demonstrate the first study on mass-selected protonated (SO⋅) Hcy ions in the gas phase by investigating its unimolecular dissociation pathways from low energy collision-induced dissociation (CID). Tandem mass spectrometry (MS/MS), stable-isotope labeling, and theoretical calculations were employed to rationalize the observed fragmentation pathways. The dominant dissociation channel of protonated (SO⋅) Hcy was a charge-directed H2 O loss from the protonated sulfinyl radical (-SO⋅) moiety, forming a thiyl radical (-S⋅), which further triggered sequential radical-directed ⋅SH loss through multiple pathways. Compared to cysteine sulfinyl radical ((SO⋅) Cys), the small structural change induced by one additional methylene group in the side chain of (SO⋅) Hcy significantly promotes its base property while reducing the radical reactivity of sulfinyl radical. This observation provides new insight into studying reactions of (SO⋅) Hcy with biomolecules, which are critical in understanding toxicity induced by high levels of Hcy in biological conditions.
    Preview · Article · Nov 2015 · Chemistry - A European Journal
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    ABSTRACT: A semi-global potential energy surface (PES) and quartic force field (QFF) based on fitting high-level electronic structure energies are presented to describe the structures and spectroscopic properties of NNHNN+. The equilibrium structure of NNHNN+ is linear with the proton equidistant between the two nitrogen groups and thus of D∞h symmetry. Vibrational second-order perturbation theory (VPT2) calculations based on the QFF fails to describe the proton "rattle" motion, i.e., the antisymmetric proton stretch, due to the very flat nature of PES around the global minimum, but per- forms properly for other modes with sharper potential wells. Vibrational self-consistent field/virtual state configuration interaction (VSCF/VCI) calculations using a version of MULTIMODE without angular momentum terms successfully describe this motion and predict the fundamental to be at 759 cm-1. This is in good agreement with the value of 746 cm-1 from a fixed-node diffusion Monte Carlo calculation and the experi- mental Ar-tagged result of 743 cm-1. Other VSCF/VCI energies are in good agreement with other experimentally reported ones. Both double-harmonic intensity and rigorous MULTIMODE intensity calculations show the proton-transfer fundamental has strong intensity.
    No preview · Article · Nov 2015 · The Journal of Physical Chemistry A
  • Xian-Hu Zha · Qing Huang · Jian He · Heming He · Junyi Zhai · Yue Wu · Joseph S. Francisco · Shiyu Du
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    ABSTRACT: In this work, we investigate the thermal and electrical properties of oxygen-functionalized M2CO2 (M = Ti, Zr, Hf) MXenes using first-principles calculations. Hf2CO2 is found to exhibit a thermal conductivity better than MoS2 and phosphorene. The room temperature thermal conductivity along the armchair direction is determined to be 86.25-131.2 Wm-1K-1 with a flake length of 5-100 um, and the corresponding value in the zigzag direction is approximately 42% of that in the armchair direction. Other important thermal properties of M2CO2 are also considered, including their specific heat and thermal expansion coefficients. The theoretical room temperature thermal expansion coefficient of Hf2CO2 is 6.094x10-6 K-1, which is lower than that of most metals. Moreover, Hf2CO2 is determined to be a semiconductor with a band gap of 1.657 eV and to have high and anisotropic carrier mobility. At room temperature, the Hf2CO2 hole mobility in the armchair direction (in the zigzag direction) is determined to be as high as 13.5x103 cm2V-1s-1 (17.6x103 cm2V-1s-1), which is comparable to that of phosphorene. Broader utilization of Hf2CO2 as a material for nanoelectronics is likely because of its moderate band gap, satisfactory thermal conductivity, low thermal expansion coefficient, and excellent carrier mobility. The corresponding thermal and electrical properties of Ti2CO2 and Zr2CO2 are also provided here for comparison. Notably, Ti2CO2 presents relatively low thermal conductivity and much higher carrier mobility than Hf2CO2, which is an indication that Ti2CO2 may be used as an efficient thermoelectric material.
    No preview · Article · Oct 2015
  • Source
    Tarek Trabelsi · O. Yazidi · J. S. Francisco · R. Linguerri · M. Hochlaf
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    ABSTRACT: The low-energy electronic states of NSO anion and its SNO isomeric form for the singlet, triplet, and quintet spin multiplicities have been investigated by accurate ab initio approaches and large atomic basis sets. One-dimensional cuts of the three-dimensional potential energy surfaces (PESs) along selected interatomic distances and bending angles for these states have been calculated to assess the formation and stability of NSO− and SNO− in the gas phase. Results show that these anions have two low-energy states ( X˜1A′ and 13A″) that are bound and stable with respect to electron detachment. Owing to the energetic position of the dissociating asymptotes of the neutral and anionic species, several electronic excited states are suggested to be stable with respect to the electron autodetachment process in the long-range parts of the potentials before reaching the molecular region. The nature of the PESs in these regions and their implications and effects on the formation of SNO− from atomic and molecular fragments are discussed. This information is essential for a better understanding of the potential role of these species in diverse media.
    Full-text · Article · Oct 2015 · The Journal of Chemical Physics
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    ABSTRACT: Results are presented that suggest that thiazyl hydride (HSN)/thionitrosyl hydride (sulfimide, HNS) can be used as light-sensitive compounds for NO-delivery in biological media, as well as markers for the possible detection of intermediates in nitrites + H2S reactions at the cellular level. They are expected to be more efficient than the HNO/HON isovalent species and hence they should be considered instead. A set of characteristic spectroscopic features are identified that could aid in the possible detection of these species in the gas phase or in biological environments. The possibility of intramolecular dynamical processes involving excited states that are capable of interconverting HNS and its isomeric form HSN is examined.
    Full-text · Article · Oct 2015 · The Journal of Chemical Physics
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    ABSTRACT: We use ab initio calculations to investigate the energetics and kinetics associated with carbinolamine formation resulting from the addition of dimethylamine to formaldehyde catalyzed by a single water molecule. Further, we compare the energetics for this reaction with that for the analogous reactions involving respectively, methylamine and ammonia. We find that the reaction barrier for the addition of these nitrogen containing molecules onto formaldehyde decreases along the series: ammonia, methylamine, and dimethylamine. Hence, starting with ammonia, the reaction barrier can be "tuned" by the substitution of an alkyl group in place of a hydrogen atom. The reaction involving dimethylamine has the lowest barrier with the transition state (TS) being 5.4 kcal/mol below the (CH3)2NH + H2CO + H2O separated reactants. This activation energy is significantly lower than that for the bare reaction occurring without water, H2CO + (CH3)2NH, which has a barrier of 20.1 kcal/mol. The negative barrier associated with the single-water molecule catalyzed reaction of dimethylamine with H2CO to form the carbinolamine (CH3)2NCH2OH suggests that this reaction should be energetically feasible under atmospheric conditions. This is confirmed by rate calculations which suggest that the reaction will be facile even in the gas phase. As amines and oxidized organics containing carbonyl functional groups are common components of secondary organic aerosols (SOA), the present finding has important implications for understanding how larger, less volatile organic compounds, can be generated in the atmosphere by combining readily available smaller components as required for promoting aerosol growth.
    No preview · Article · Sep 2015 · The Journal of Physical Chemistry A
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    ABSTRACT: In the present work, the behavior of He in the MAX phase Ti3AlC2 material is investigated using first-principle methods. It is found that, according to the predicted formation energies, a single He atom favors residing near the Al plane in Ti3AlC2. The results also show that Al vacancies are better able to trap He atoms than either Ti or C vacancies. The formation energies for the secondary vacancy defects near an Al vacancy or a C vacancy are strongly influenced by He impurity content. According to the present results, the existence of trapped He atoms in primary Al vacancy can promote secondary vacancy formation and the He bubble trapped by Al vacancies has a higher tendency to grow in the Al plane of Ti3AlC2. The diffusion of He in Ti3AlC2 is also investigated. The energy barriers are approximately 2.980 eV and 0.294 eV along the c-axis and in the ab plane, respectively, which means that He atoms exhibit faster migration parallel to the Al plane. Hence, the formation of platelet-like bubbles nucleated from the Al vacancies is favored both energetically and kinetically. Our calculations also show that the conventional spherical bubbles may be originated from He atoms trapped by C vacancies. Taken together, these results are able to explain the observed formation of bubbles in various shapes in recent experiments. This study is expected to provide new insight into the behaviors of MAX phases under irradiation from electronic structure level in order to improve the design of MAX phase based materials.
    Full-text · Article · Sep 2015 · The Journal of Chemical Physics
  • Bifeng Zhu · Xiaoqing Zeng · Helmut Beckers · Joseph S. Francisco · Helge Willner
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    ABSTRACT: Atmospheric Chemistry. In their Communication on page 11404 ff., H. Beckers et al. report the isolation of methylsulfonyloxyl radicals, key intermediates in the atmospheric oxidation of dimethyl sulfide.
    No preview · Article · Sep 2015 · Angewandte Chemie International Edition
  • Manoj Kumar · Joseph S Francisco
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    ABSTRACT: Quantum chemical calculations have been carried out to investigate the gas-phase structure, stability, and decomposition of the two simplest alkanediols, methanediol and 1,1-ethanediol, in the presence of various catalysts. Three different conformers for monomeric alkanediols namely cis, trans, and trans' were considered. The calculations reveal that alkanediols may exist not only as monomers but also as dimers that have high binding energies of 7-11 kcal/mol due to hydrogen bonding among the oxygenate functionalities. Some of these dimers have high dipole moments and, thus, may be more easily detected experimentally than the monomers of alkanediols. For the decomposition of alkanediols, the calculations dominantly favor dehydration over dehydrogenation. The relatively low barrier for the decomposition of 1,1-ethanediol suggests that the structure of an alkanediol plays a role in its decomposition. Though the dehydration of alkanediols with or without water catalyst involves large barriers, organic and inorganic acids, the hydroperoxyl radical catalytically influences the reaction to such an extent that the dehydration reaction either involves significantly reduced barriers or essentially becomes barrierless. Considering that alkanediols contain hydroxyl groups and their dimers have high binding energies, the gas-phase dehydration may be self-driven. Because acids are present in significant amounts in the troposphere, results suggest that diol dehydration may be facile under atmospheric conditions.
    No preview · Article · Sep 2015 · The Journal of Physical Chemistry A
  • Joseph S. Francisco
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    ABSTRACT: Interkulturelle Kooperation ist, wenn sie funktioniert, synergistisch und bringt ein Verstehen von Partnern mit sich, das jeder für sich allein wohl kaum erreichen kann. Überall auf der Welt gibt es Menschen, die etwas wissen, doch niemand weiß alles. Internationale Kooperationen bringen Wissen und Ressourcen zusammen und ziehen Nutzen aus deren weltweiter Verbreitung und dem menschlichen Streben nach mehr Wissen …” Lesen Sie mehr im Editorial von Joseph S. Francisco.
    No preview · Article · Sep 2015 · Angewandte Chemie
  • Joseph S. Francisco
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    ABSTRACT: Cross-cultural collaboration, when it works, is synergistic, and brings understanding between partners that neither is likely to be able to develop alone. There are people in the world that know something, but nobody knows everything. International collaborations in science bring together and capitalize on the dispersal of knowledge and resources across the globe, and the human desire to advance knowledge …” Read more in the Editorial by Joseph S. Francisco.
    No preview · Article · Sep 2015 · Angewandte Chemie International Edition
  • Hui Li · Joseph S Francisco · Xiao Cheng Zeng
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    ABSTRACT: Recently reported synthetic organic nanopore (SONP) can mimic a key feature of natural ion channels, i.e., selective ion transport. However, the physical mechanism underlying the K(+)/Na(+) selectivity for the SONPs is dramatically different from that of natural ion channels. To achieve a better understanding of the selective ion transport in hydrophobic subnanometer channels in general and SONPs in particular, we perform a series of ab initio molecular dynamics simulations to investigate the diffusivity of aqua Na(+) and K(+) ions in two prototype hydrophobic nanochannels: (i) an SONP with radius of 3.2 Å, and (ii) single-walled carbon nanotubes (CNTs) with radii of 3-5 Å (these radii are comparable to those of the biological potassium K(+) channels). We find that the hydration shell of aqua Na(+) ion is smaller than that of aqua K(+) ion but notably more structured and less yielding. The aqua ions do not lower the diffusivity of water molecules in CNTs, but in SONP the diffusivity of aqua ions (Na(+) in particular) is strongly suppressed due to the rugged inner surface. Moreover, the aqua Na(+) ion requires higher formation energy than aqua K(+) ion in the hydrophobic nanochannels. As such, we find that the ion (K(+) vs. Na(+)) selectivity of the (8, 8) CNT is ∼20× higher than that of SONP. Hence, the (8, 8) CNT is likely the most efficient artificial K(+) channel due in part to its special interior environment in which Na(+) can be fully solvated, whereas K(+) cannot. This work provides deeper insights into the physical chemistry behind selective ion transport in nanochannels.
    No preview · Article · Sep 2015 · Proceedings of the National Academy of Sciences
  • Jie Zhong · Yu Zhao · Lei Li · Hui Li · Joseph S Francisco · Xiao Cheng Zeng
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    ABSTRACT: We present a comprehensive computational study of NH2 (radical) solvation in a water nanodroplet. The ab initio Born-Oppenheimer molecular dynamics simulation shows that NH2 tends to accumulate at the air-water interface. The hydrogen bonding analysis shows that compared to the hydrogen bond of HNH··OH2, the hydrogen bond of HOH··NH2 is the dominant interaction between NH2 and water. Due to the loose hydrogen bonding network formed between NH2 and the droplet interface, the NH2 can easily move around on the droplet surface, which speeds up the dynamics of NH2 at the air-water interface. Moreover, the structural analysis indicates that the NH2 prefers an orientation such that both N atom and one of its H atoms interact with the water droplet while the other H atom is mostly ex-posed to the air. The exposed hydrogen becomes a more probable reactive site for reaction at the water interface. More importantly, the solvation of NH2 modifies the amplitude of vibration of the N-H bond, thereby affecting the Mulliken charges and electrophilicity of NH2. As such, reactive properties of the NH2 are altered by the droplet interface and this can either speed up reactions or allow other reactions processes to occur in the atmosphere. Hence, the solvation of NH2 on water droplets, in chemistry of the atmosphere, may not be negligible when considering the effects of clouds.
    No preview · Article · Sep 2015 · Journal of the American Chemical Society
  • Ryan C. Fortenberry · Joseph S. Francisco
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    ABSTRACT: The SNO and OSN radical isomers are likely to be of significance in atmospheric and astrochemistry, but very little is known about their gas phase spectroscopic properties. State-of-the-art ab initio composite quartic force fields are employed to analyze the rovibrational features for both systems. Comparison to condensed-phase experimental data for SNO has shown that the 1566.4 cm−1 ν 1 N–O stretch is indeed exceptionally bright and likely located in this vicinity for subsequent gas phase experimental analysis. The OSN ν 1 at 1209.4 cm−1 is better described as the antisymmetric stretch in this molecule and is also quite bright. The full vibrational, rotational, and rovibrational data are provided for SNO and OSN and their single 15N, 18O, and 34S isotopic substitutions in order to give a more complete picture as to the chemical physics of these molecules.
    No preview · Article · Aug 2015 · The Journal of Chemical Physics

Publication Stats

7k Citations
1,859.74 Total Impact Points


  • 1994-2016
    • Purdue University
      • • Department of Chemistry
      • • Department of Earth and Atmospheric Sciences
      ウェストラファイエット, Indiana, United States
    • NASA
      Вашингтон, West Virginia, United States
  • 2014-2015
    • University of Nebraska at Lincoln
      • Department of Chemistry
      Lincoln, Nebraska, United States
  • 2001-2010
    • Haverford College
      • Department of Chemistry
      Norristown, Pennsylvania, United States
  • 1987-2007
    • Wayne State University
      • Department of Chemistry
      Detroit, MI, United States
  • 2005
    • Bergische Universität Wuppertal
      • Inorganic Chemistry
      Wuppertal, North Rhine-Westphalia, Germany
  • 2002
    • Texas A&M University
      • Department of Chemistry
      College Station, Texas, United States
  • 1999
    • Williams College
      • Department of Chemistry
      Williamstown, New Jersey, United States
    • California State University, Los Angeles
      • Department of Chemistry and Biochemistry
      Los Ángeles, California, United States
  • 1998
    • University of Illinois, Urbana-Champaign
      • Department of Atmospheric Sciences
      Urbana, Illinois, United States
  • 1993-1997
    • California Institute of Technology
      • Jet Propulsion Laboratory
      Pasadena, California, United States
  • 1990-1995
    • University of Bath
      • Department of Chemistry
      Bath, ENG, United Kingdom
  • 1981-1991
    • Griffith University
      Southport, Queensland, Australia
    • University of Adelaide
      • School of Chemical Engineering
      Tarndarnya, South Australia, Australia
  • 1988
    • University of Detroit Mercy
      • Department Chemistry and Biochemistry
      Detroit, Michigan, United States
  • 1984-1985
    • University of Cambridge
      Cambridge, England, United Kingdom
  • 1981-1984
    • Massachusetts Institute of Technology
      • Department of Chemistry
      Cambridge, Massachusetts, United States