Towards Fundamental Understanding and Rational Control of Crystal Growth

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Towards Fundamental Understanding and Rational
Control of Crystal Growth

• Tonglei Li, University of Kentucky, DMR-0449633

The project focuses on understanding the role
played by solvents and additives in affecting
growth morphology and polymorphism of organic
crystals with density functional theory (DFT)
based concepts and Pearson's HSAB (hard and soft
acids and bases) Principle. Solvent molecules
should match crystal surfaces of a particular
polymorph or morphology with respect to their
electronic properties. As the sea of electrons on
various faces of a crystal couples with or
responds to electronic perturbations due to
contact of a solvent/additive, the difference in
responding sensitivities of the faces may be
described by DFT-based softness and hardness.
Applying these concepts to establish HSAB type
matching principles between solvents/additives
and crystals, we will create a new paradigm to
clarify the influence of solvents and additives
at the electronic level, advancing the rational
design of novel crystal materials for chemical,
pharmaceutical and biomedical applications.
Surface softness calculated by DFT of two major
faces of aspirin. There are two different cuts
of the (100) face. The inset picture is the
(001) face calculated.
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Towards Fundamental Understanding and Rational
Control of Crystal Growth
Tonglei Li, University of Kentucky, DMR-0449633
Photos Left Shaoxin Feng (1st-year graduate
student), Zhan Wang (master student), Stephanie
Wendschlag (undergraduate student, chemical
engineering) and Clare Aubrey (3rd-year graduate
student) Middle Sakib Motalib (high-school
senior) doing visualization of electron density
calculated of acetaminophen crystal Right Ellen
Savelli (undergraduate student, pre-pharmacy)
doing contact angle measurement of a crystal
surface