Chem105 , General Chemistry II
Chem250 , Physical Chemistry I
Chem250_lecture5A , Raoult and Henry
Chem251 , Physical Chemistry II
Chem360 , Quantum Chemistry
Chem360_lecture7X , Perturbation Theory
Chem360 Test 1 stuff
Chem360 Test 2 stuff
Chem360 exam stuff
Chem461 , Computational Chemistry
Chem461 estrogen nmr
Chem867 , Advanced Theoretical Chemistry
G09 on Dextrose
Solving Challenging Problems with Theoretical Chemistry
Our research interests lie in the application of quantum chemistry
methods and theoretical chemistry to solve challenging problems
and long-standing mysteries in chemistry.
In the current grant cycle (2016-2021) we have been focusing on several research projects that involve the chemistry of ions. We have made recent breakthroughs in (i) understanding carbocation rearrangment (paper 64 below), (ii) curing errors in acid-catalysis computations (papers 69 and 63), and (iii) explaining electrolyte conductivity phenomena of molten salt (papers 56,58,65,66) and protic ionic liquids (paper 70).
We discovered, in 2012, a Grotthuss conductivity mechanism involving hopping halide ions, rather than hopping H+ ions. There is an associated activation energy, Ea, for Grotthuss conductivity, which rises during thermal expansion, and this is the reason for conductivity maxima versus temperature. This affects both network (BiCl3) and molecular (HgBr2) melts, and we are currently extending this study to more molten salts. In ionic liquids (molten salts with lower melting points), many have partial ionic character, with maximum conductivity at odd mixing ratios; we have uncovered effects due to dielectric constant and ion-pairing equilibria, both of which are affected by mixing ratio. In such systems, the conductivity mechanism appears to be translation of ion complexes, not Grotthuss H+ hopping, in our simulations; research eagerly continues in this new research direction.
Ion chemistry: petroleum refining, acid catalysis, etc.
Acidic ionic liquids could replace zeolites as a material of choice in petroleum cracking, and we study the chemistry of both. While ionic liquids offer a substantial lowering of energy input (can crack at much lower temperatures), product selectivity is lost, and a hybrid technology is desired. Currently we are solving the difficult problem of zeolite modelling.
Acid catalysis of many organic reactions has been difficult to model because of large errors in traditional quantum chemistry calculations. We discovered that the problem is almost entirely to do with the modelling of H3O+ ions, and are leading the world in applying semicontinuum modelling to such problems.
Gas-phase dimers and excimers.
We have expertise in the computational prediction of structure and IR/UV spectra of weakly-bound gas-phase dimers, such as (NO)2, (NNO)2, and naphthalene dimer. We are open to assist experimentalists in projects of this kind.