A correlation between surface wettability and solvent effect on crystal growth. The N-n-octyl-D-gluconamide/methanol system

Understanding and control of nucleation, growth, habit, dissolution and structure of two- and three-dimensional crystals using `tailor-made' auxiliaries

“…7), may be assigned from the difference in wetting properties of the hydrophilic and hydrophobic faces. In CH3OH solution the polar platelike crystals of the octyl derivative (n = 8) were found to grow almost four times faster at the hydrophobic side than at the hydrophilic side (Wang, Leiserowitz & Lahav, 1992). This result is completely in keeping with the observation that water and other polar solvents wet the hydrophilic face more strongly than the opposite hydrophobic face (see §4.1).…”

Asymmetrical growth and dissolution along polar axis of α-resorcinol crystal: role of solvent and external environment

“…By using eqn (12) along with the results presented in Table 2, we deduce that the adsorption of the M1 molecule is rate limiting for the growth of (01 1) and (011) faces of α-resorcinol crystal. Similarly employing eqn (13) along with the results presented in Table 2 it is clear that the dissolution rate of (01 1) and (011) faces of resorcinol crystal are rate-limited by the detachment of M2 molecule when the neighbouring M1 molecule is already removed prior to the M2 molecule.…”

“…The inhibition model is consistent with the mechanism of action of tailor-made additives, 7,11 which has a structure very similar to that of the molecule to be crystallized, but for an altered moiety. 12 Wang et al 13 have specifically designed an experiment to differentiate between the above mentioned mechanisms for the growth of polar crystals. They have measured the growth rates of opposite and hemihedral faces of N-n-octyl-D-gluconamide crystal in methanol solution and show that the observed growth rates along the polar axis can only be explained through an inhibition model.…”

Direct assignment of the absolute configuration of molecules from crystal morphology

“…32 This information fixes the orientation of the constituent molecules along the polar b axis of the crystal specimen and consequently their chirality. These wettability experiments also led to crystal growth experiments on these systems to help determine the role of the solvent on crystal growth.…”

“…The crystals exposing the hydrophobic face grew four to five times faster in comparison to those that exposed the hydrophilic face to the same solution. 32 An attempt to assign the sense of polarity of glycine bpolymorph (b-Gly) specimen crystals, space group P 2 1 , via the Bijvoet method was unsuccessful because the atoms are weak anomalous X-ray scatterers and the molecular arrangement, when only the relevant O, N, C atoms need be considered, is nearly centrosymmetric (space group pseudo-P 2 1 /m). Growth kinetic measurements of single bGly crystals in 1:1 ethanol-water solutions revealed a fast growth at one end of the needle-like crystal (the polar baxis is along the needle direction) and a very slow growth at the opposite end.…”