하정명 교수

Polymorph selectivity has been achieved during crystallization of anthranilic acid (AA) and 5-methyl-2-[(2-nitrophyenyl)amino]-3-thiophenecarbonitrile (ROY), both considered benchmarks of polymorphic behavior, within nanoporous glass beads and polymer monoliths. Whereas polymorph III of AA crystallizes from the melt on nonporous glass beads or within larger pores, the metastable polymorph II crystallizes in pores with diameters <23 nm, with the selectivity toward this form increasing with decrea

Controlling polymorphism, the ability of a compound to adopt more than one solid-state structure, often relies on empirical manipulations of conditions such as solvent, temperature, and mode of crystallization. Despite a growing interest in nanocrystalline formulations, however, the influence of crystal size on polymorph formation and stability is largely unexplored. Nanocrystals of pimelic acid, HO2C(CH2)n-2CO2H (n = 7), glutaric acid (n = 5), suberic acid (n = 8), and coumarin (1,2-benzopyrone

Gold nanoparticles postsynthetically modified with chiral 1,3-disubstituted diamino calix[4]arene ligands 2a and 2b are shown to exhibit a circular dichroism (CD)-active surface plasmon resonance absorption (SPR) band. Electronic communication between adsorbed ligand and the gold nanoparticle surface is evidenced in an almost 10-fold increase in the ligand molar ellipticity in the pi-pi* transition spectral range when bound to the gold surface relative to free solution. The footprint of ligand o

Use of organic ligands to partially passivate nanoparticles against sintering yet retain a degree of small molecule accessibility to the metal surface has been a lofty goal in functional materials synthesis, which in principle also enables the design of preferred electronic and steric environments on a nanoparticle surface. Catalysis using gold in particular requires donor ligands that facilitate an electron-rich metal surface and generalizable strategies for dealing with deactivation due to sin

TiO2-supported Ni catalysts are promising candidates that can be used to achieve biomass valorization following the selective hydrodeoxygenation (HDO). Their catalytic activity can be tuned and they are characterized by strong metal–support interaction (SMSI). The SMSI observed at the interfaces of Ni nanoparticles (NPs) and the TiO2 support was tuned by adding Fe and subjecting the synthesis system to hydrothermal treatment conditions. The prepared catalysts promoted the selective conversion of

Crystallization of organic compounds in nanometer-scale channels of controlled pore glass (CPG) and porous polystyrene (p-PS), the latter prepared by etching of the polylactide (PLA) component of shear-aligned PS-PLA diblock copolymers, produces crystals with dimensions that reflect the size constraints imposed by the channels. The nanoscopic dimensions of the organic crystals embedded in the channels result in a substantial melting point depression compared with the bulk, as demonstrated here f