Allan L. L. East
and the
Regina Computational Chemistry Laboratory

photo of Allan Professor
Dept. of Chemistry and Biochemistry
University of Regina
Regina, Sask. S4S 0A2, Canada

Office: Room RI312, Research and Innovation Centre
Phone: 306-585-4003
Dept. Fax: 306-337-2409
e-mail:  allan.east@uregina.ca

B.Sc.(Hons) 1989, Brock University, St. Catharines, Ontario (Stuart Rothstein)
Ph.D. 1994, Stanford University, Stanford, California (Wesley Allen)

Postdoctoral Fellow, 1994-1995, Australian National University, Canberra, Australia (Leo Radom)
Research Associate, 1996-1998, National Research Council, Ottawa, Ontario (Philip Bunker)
Postdoctoral Fellow, 1999-2000, University of Akron, Akron, Ohio (Edward Lim)

Course outlines:
Chem105 , General Chemistry II
Chem250 , Physical Chemistry I
Chem251 , Physical Chemistry II
Chem360 , Quantum Chemistry
Chem360 Test 2 stuff
Chem360 exam stuff
Chem461 , Computational Chemistry
Chem461 estrogen nmr
Chem867 , Advanced Theoretical Chemistry
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Regina Computational Chemistry Laboratory:

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.
Recent breakthroughs. 
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).
Ionic conductivity. 
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.

Publications

74.   “Improving yield and rate of acid-catalyzed deconstruction of lignin by mechanochemical activation,” D. Patel, D. Marx, and A. L. L. East, Chem. Phys. Chem., published online Aug 26, 2020.

73.   “Comment on ‘Local, solvation pressures and conformational changes in ethylenediamine aqueous solutions probed using Raman spectroscopy’ by M. Caceres, A. Lobato, N. J. Mendoza, L. J. Bonales and V. G. Baonza, Phys. Chem. Chem. Phys., 2016, 18, 26192,” A. A. Mukadam, N. P. Aravindakshan, and A. L. L. East, Phys. Chem. Chem. Phys. 22 (2020), pp. 7119-7125.

72.   “The origin of the conductivity maximum in molten salts. III. Zinc halides,” N. P. Aravindakshan, K. E. Johnson, and A. L. L. East, J. Chem. Phys. 151 (2019), 034507 (10p).

71.   “Mechanical activation drastically accelerates amide bond hydrolysis, matching enzyme activity, ” M. F. Pill, A. L. L. East, D. Marx, M. K. Beyer, and H. Clausen-Schaumann, Angew. Chem. Int. Ed. 58 (2019), pp. 9787-9790. SuppInfo

70.   “The origin of the conductivity maximum vs. mixing ratio in pyridine/acetic acid and water/acetic acid, ” N. P. Aravindakshan, K. E. Gemmell, K. E. Johnson, and A. L. L. East, J. Chem. Phys. 149 (2018), 094505 (9p).

69.   “Challenges in predicting ΔrxnG in solution: Hydronium, hydroxide, and water autoionization, ” S. Dhillon and A. L. L. East, Int. J. Quantum Chem. 118 (2018), e27503.

68.   “On the hydrolysis mechanisms of amides and peptides, ” A. L. L. East, Int. J. Chem. Kinet. 50 (2018), pp. 705-709.

67.   “What causes the nonclassical structure of 2-norbornyl ion? ” R. A. Patel and A. L. L. East, Can. J. Chem. 94 (2016), pp. 1044-1048.

66.   “The origin of the conductivity maximum in molten salts. II. SnCl2 and HgBr2,” N. P. Aravindakshan, C. M. Kuntz, K. E. Gemmell, K. E. Johnson, and A. L. L. East, J. Chem. Phys. 145 (2016), 094504 (12p).

65.   “Conductivity maxima vs. temperature: Grotthuss conductivity in aprotic molten salts,” N. P. Aravindakshan, C. M. Kuntz, K. E. Gemmell, K. E. Johnson, and A. L. L. East, Electrochem. Soc. Trans. 75, no. 15 (2016), pp. 575-583.

64.   “The carbocation rearrangment mechanism, clarified,” D. J. S. Sandbeck, D. J. Markewich, and A. L. L. East, J. Org. Chem. 81 (2016), pp. 1410-1415.

63.   “Semicontinuum solvation modeling improves predictions of carbamate stability in the CO2 + aqueous amine reaction,” K. Z. Sumon, C. H. Bains, D. J. Markewich, A. Henni, and A. L. L. East, J. Phys. Chem. B 119 (2015), pp. 12256-12264.

62.   “Challenges in predicting ΔrxnG in Solution: The mechanism of ether-catalyzed hydroboration of alkenes,” D. J. S. Sandbeck, C. M. Kuntz, C. Luu, R. A. Mondor, J. G. Ottaviano, A. V. Rayer, K. Z. Sumon, and A. L. L. East, J. Phys. Chem. A 118 (2014), pp. 11768-11779.

61.   “Molecular dynamics simulations of proposed intermediates in the CO2 + aqueous amine reaction,” K. Z. Sumon, A. Henni, and A. L. L. East, J. Phys. Chem. Lett. 5 (2014), pp. 1151-1156.

60.   “Bite angle effects of dppm vs dppe in seven-coordinate complexes: a DFT case study,” A. Chacko, U. R. Idem, C. H. Bains, L. M. Mihichuk, and A. L. L. East, Organometallics 32 (2013), pp. 5374-5383.

59.   “Predicting pKa of amines for CO2 capture: computer versus pencil-and-paper,” K. Z. Sumon, A. Henni, and A. L. L. East, Ind. Eng. Chem. Res. 51 (2012) pp. 11924-11930.

58.   “An Arrhenius argument to explain electrical conductivity maxima versus temperature,” C. M. Kuntz and A. L. L. East, Electrochem. Soc. Trans. 50, no. 11 (2012), pp. 71-78.

57.   “Kinetics and Dissociation Constants (pKa) of Polyamines of Importance in Post-Combustion Carbon Dioxide (CO2) Capture Studies,” F. Khalili, A. V. Rayer, A. Henni, A. L. L. East and P. Tontiwachwuthikul, in Recent Advances in Post-Combustion CO2 Capture Chemistry, M. I. Attalla ed., ACS Symposium Series; American Chemical Society (Washington DC), 2012.

56.   “The origin of the conductivity maximum in molten salts. I. Bismuth chloride,” A. T. Clay, C. M. Kuntz, K. E. Johnson, and A. L. L. East, J. Chem. Phys. 136 (2012), 124504 (11p).

55.   “The mechanism of permanganate oxidation of sulfides and sulfoxides,” A. Jayaraman and A. L. L. East, J. Org. Chem. 77 (2012) pp. 351-356.

54.   “Tungsten(II)-catalyzed rearrangements of norbornadiene: Effects of alternative complexation stages,” A. Jayaraman, G. M. Berner, L. M. Mihichuk, and A. L. L. East, J. Mol. Catal. A: Chemical 351 (2011) pp. 143-153.

53.   “Supra-supra, supra-antara, and stepwise-diradical pathways for an observed 16-electron double-[4+4] cycloaddition within metal-templated dialkyne dimers (PtX2)2(μ-R2PCCCCPR2)2,” A. Chacko, B. T. Sterenberg, and A. L. L. East, J. Phys. Chem. A 115 (2011), pp. 4951-4958.

52.   “Si-H bond activation by electrophilic phosphinidene complexes,” K. Vaheesar, T. M. Bolton, A. L. L. East,and B. T. Sterenberg, Organometallics 29 (2010), pp. 484-490.

51.   “Entropy contributions in pKa computation: Application to alkanolamines and piperazines,” F. Khalili, A. Henni, and A. L. L. East, J. Mol. Struc. THEOCHEM 916 (2009) pp. 1-9.

50.   “Catalyzed beta scission of a carbenium ion III - Scission observed in ab initio molecular dynamics simulations,” G. M. Berner and A. L. L. East, Can. J. Chem. 87 (2009), pp. 1512-1520.

49.   “pKa values of some piperazines at (298, 303, 313, and 323) K,” F. Khalili, A. Henni, and A. L. L. East, J. Chem. Eng. Data 54 (2009), pp. 2914-2917.

48.   “On the structure and dynamics of secondary n-alkyl cations,” A. L. L. East, T. Bucko, and J. Hafner, J. Chem. Phys. 131 (2009), 104314 (10p).

47.   “Nitrous oxide dimer: An ab initio coupled-cluster study of isomers, interconversions, and infrared fundamental bands, and experimental observation of a new fundamental for the polar isomer, ” G. M. Berner, A. L. L. East, M. Afshari, M. Dehghany, N. Moazzen-Ahmadi, and A. R. W. McKellar, J. Chem. Phys. 130 (2009), 164305 (8p).

46.   “Computational study of tungsten(II)-catalyzed rearrangements of norbornadiene, ” A. L. L. East, G. M. Berner, A. D. Morcom, and L. Mihichuk, J. Chem. Theory Comput. 4 (2008), pp. 1274-1282.

45.   “Photochemistry studied with ab initio orbital-correlation and state-correlation plots: Classic cyclobutene ring opening, and the reaction of N2 with photoexcited O2, ” H. Shi, D. C. Roettger, and A. L. L. East, J. Comp. Chem. 29 (2008), pp. 883-891. (Accepted Aug. 2007, published online Oct. 2007, but not in print until April 2008!)

44.   “Carbocation branching observed in a simulation, ” A. L. L. East, T. Bucko, and J. Hafner, J. Phys. Chem. A 111 (2007), pp. 5945-5947.

43.   “Short-range order in liquid aluminum chloride: ab initio molecular dynamics simulations and quantum-chemical calculations, ” A. L. L. East and J. Hafner, J. Phys. Chem. B 111 (2007), pp. 5316-5321.

42.   “Catalyzed beta scission of a carbenium ion II -- Variations leading to a general mechanism,” Q. Li and A. L. L. East, Can. J. Chem. 84 (2006), pp. 1159-1166.

41.   “Improved results for the excited states of nitric oxide, including the B/C avoided crossing,” H. Shi and A. L. L. East, J. Chem. Phys. 125 (2006), 104311 (7p).

40.   “Photodissociation dynamics of the NO dimer: 1. Theoretical overview of the ultraviolet singlet excited states,” S. V. Levchenko, H. Reisler, A. I. Krylov, O. Gessner, A. Stolow, H. Shi, and A. L. L. East, J. Chem. Phys. 125 (2006), 084301 (12p).

39.   “Competing isomerizations: a combined experimental/theoretical study of phenylpentenone isomerism,” Z. Wang, A. G. H. Wee, S. S. Hepperle, R. G. Treble, and A. L. L. East, J. Phys. Chem. A 110 (2006), pp. 5985-5989.

38.   “Femtosecond multidimensional imaging of a molecular dissociation,” O. Gessner, A. M. D. Lee, J. P. Shaffer, H. Reisler, S. V. Levchenko, A. I. Krylov, J. G. Underwood, H. Shi, A. L. L. East, D. M. Wardlaw, E. t. H. Chrysostom, C. C. Hayden, and A. Stolow, Science 311 (2006), pp. 219-222.

37.   “Length and substituent-scrambling energies of parent and halogen-substituted conjugated polyynes,” A. L. L. East, K. L. Grittner, A. I. Afzal, A. G. Simpson, and J. F. Liebman, J. Phys. Chem. A 109 (2005), pp. 11424-11428.

36.   “Mechanism of cis/trans equilibration of alkenes via iodine catalysis,” S. S. Hepperle, Q. Li, and A. L. L. East, J. Phys. Chem. A 109 (2005), pp. 10975-10981.

35.   “Catalyzed beta scission of a carbenium ion -- mechanistic differences from varying catalyst basicity,” Q. Li and A. L. L. East, Can. J. Chem. 83 (2005), pp. 1146-1157.

34.   “A theoretical comparison of Lewis-acid versus Bronsted-acid catalysis for n-hexane to propane + propene,” Q. Li, K. C. Hunter, and A. L. L. East, J. Phys. Chem. A 109 (2005), pp. 6223-6231.

33.   “Entropy from quantum chemical computations,” A. L. L. East, Encyclopedia of Computational Chemistry (online), Wiley Interscience, 2004.

32.   “Geometry and torsional energies of a C-C-protonated n-alkane,” Q. Li, K. C. Hunter, C. Seitz, and A. L. L. East, J. Chem. Phys. 119 (2003), pp. 7148-7155.

31.   “Polyyne bending frequencies:  Why they vary with the square of the harmonic in the infinite limit,” C. Seitz and A. L. L. East, Mol. Phys. 101 (2003), pp. 1267-1271.

30.   “A mechanistic study of the Bronsted-acid catalysis of n-hexane to propane + propene, featuring carbonium ions,” K. C. Hunter, C. Seitz, and A. L. L. East, J. Phys. Chem. A 107 (2003), pp. 159-168.

29.   “The isomers of protonated octane, C8H19+,” C. Seitz and A. L. L. East, J. Phys. Chem. A 106 (2002), pp. 11653-11662.

28.   “Properties of C-C bonds in n-alkanes: Relevance to cracking mechanisms,” K. C. Hunter and A. L. L. East, J. Phys. Chem. A 106 (2002), pp. 1346-1356.

27.   “Interlocking triplet electronic states of isocyanic acid: Sources of nonadiabatic photofragmentation dynamics,” E. F. Valeev, W. D. Allen, H. F. Schaefer III, A. G. Csaszar, and A. L. L. East, J. Phys. Chem. A 105 (2001), pp. 2716-2730.

26.   “Naphthalene dimer: electronic states, excimers, and triplet decay,” A. L. L. East and E. C. Lim, J. Chem. Phys. 113 (2000), pp. 8981-8994.

25.   “Conformational geometries and conformation-dependent photophysics of jet-cooled 1,3-diphenylpropane,” A. L. L. East, P. Cid-Aguero, H. Liu, R. H. Judge, and E. C. Lim, J. Phys. Chem. A 104 (2000), pp. 1456-1460.

24.   “Comment on ‘High level ab initio and density functional study of the CH + NO reaction product branching’,” A. L. L. East and W. D. Allen, J. Phys. Chem. A 104 (2000), p. 1362.

23.   “Toluene internal-rotation:  Measurement and simulation of the high-resolution S1-S0 fluorescence excitation spectrum at 0.5 K,” A. L. L. East, H. Liu, E. C. Lim, P. Jensen, I. Dechene, M. Zgierski, W. Siebrand, and P. R. Bunker, J. Chem. Phys. 112 (2000), pp. 167-175.

22.   “On the photoelectron spectrum of the NO dimer, and ground state of (NO)2+,” A. L. L. East and J. K. G. Watson, J. Chem. Phys. 110 (1999), pp. 6099-6102.

21.   “The three isomers of protonated ethane, C2H7+,” A. L. L. East, Z. F. Liu, C. McCague, K. Cheng, and J. S. Tse, J. Phys. Chem. A 102 (1998), pp. 10903-10911.

20.   “The intermolecular vibrations of the NO dimer,” A. L. L. East, A. R. W. McKellar, and J. K. G. Watson, J. Chem. Phys. 109 (1998), pp. 4378-4383.

19.   “The 16 valence electronic states of nitric oxide dimer, (NO)2,” A. L. L. East, J. Chem. Phys. 109 (1998), pp. 2185-2193.

18.   “The kinkiness of cumulenones:  H2C3O, H2C4O, and H2C5O,” A. L. L. East, J. Chem. Phys. 108 (1998), pp. 3574-3584.

17.   “An ab initio calculation of the rotation and internal-rotation energy levels of the ethyl radical,” A. L. L. East and P. R. Bunker, Chem. Phys. Lett. 282 (1998), pp. 49-53

16.   “Entropies and free energies of protonation and proton transfer reactions,” A. L. L. East, B. J. Smith, and L. Radom, J. Am. Chem. Soc. 119 (1997), pp. 9014-9020.

15.   “An ab initio calculation of the rotational spectrum of CH5+ and CD5+,” A. L. L. East, M. Kolbuszewski, and P. R. Bunker, J. Phys. Chem. A 101 (1997), pp. 6746-6752.

14.   “The potential surface for the three methyl rotations in the tertiary-butyl cation, (CH3)3C+,” A. L. L. East, J. Chem. Phys. 107 (1997), pp. 3914-3920.

13.   “A general rotation-contortion hamiltonian with structure relaxation:  application to the precessing internal rotor model,” A. L. L. East and P. R. Bunker, J. Mol. Spectrosc. 183 (1997), pp. 157-162.

12.   “Ab initio statistical thermodynamical models for the computation of third-law entropies,” A. L. L. East and L. Radom, J. Chem. Phys. 106 (1997), pp. 6655-6674.

11.   “A high level ab initio map and direct statistical treatment of the fragmentation of singlet ketene,” S. J. Klippenstein, A. L. L. East, and W. D. Allen, J. Chem. Phys. 105 (1996), pp. 118-140.

10.   “A comparison of high-quality ab initio basis sets:  the inversion barrier in ammonia,” A. L. L. East and L. Radom, J. Mol. Struct. 376 (1996), pp. 437-447.

9.   “The anharmonic force field and equilibrium molecular structure of ketene,” A. L. L. East, W. D. Allen, and S. J. Klippenstein, J. Chem. Phys. 102 (1995), pp. 8506-8532.

8.   “A first principles theoretical determination of the rate constant for the dissociation of singlet ketene,” S. J. Klippenstein, A. L. L. East, and W. D. Allen, J. Chem. Phys. 101 (1994), pp. 9198-9201.

7.   “The proton-transfer surface of CH3OHF–,” B. D. Wladkowski, A. L. L. East, J. E. Mihalick, W. D. Allen, and J. I. Brauman, J. Chem. Phys. 100 (1994), pp. 2058-2088.

6.   “The heat of formation of NCO,” A. L. L. East and W. D. Allen, J. Chem. Phys. 99 (1993), pp. 4638-4650.

5.   “The [FHCl]– molecular anion:  structural aspects, global surface, and vibrational eigenspectrum,” N. E. Klepeis, A. L. L. East , A. G. Császár, W. D. Allen, T. J. Lee, and D. W. Schwenke, J. Chem. Phys. 99 (1993), pp. 3865-3897.

4.   “Ab Initio Anharmonic Vibrational Analyses of Non-Rigid Molecules,” W. D. Allen, A. L. L. East, and A. G. Császár, in Structures and Conformations of Non-Rigid Molecules, edited by J. Lanne, M. Dakkouri, B. van der Veken, and H. Oberhammer (Kluwer, Dordrecht,1993).

3.   “Characterization of the X1A' state of isocyanic acid,” A. L. L. East, C. S. Johnson, and W. D. Allen, J. Chem. Phys. 98 (1993), pp. 1299-1328.

2.   “Reply to 'Comment on “Sampling the exact electron distribution by diffusion quantum Monte Carlo,”'” A. L. L. East, S. M. Rothstein, and J. Vrbik, J. Chem. Phys. 92 (1990), pp. 2120.

1.   “Sampling the exact electron distribution by diffusion quantum Monte Carlo,” A. L. L. East, S. M. Rothstein, and J. Vrbik, J. Chem. Phys. 89 (1988), pp. 4880-4884.

This page was last updated August 28, 2020 (Allan East).