Table 3.1.1.1

Lindley, P. F.

doi:10.1107/97809553602060000585

International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

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International Tables for Crystallography (2006). Vol. C. ch. 3.1, p. 149

Table 3.1.1.1

P. F. Lindley^a

^a ESRF, Avenue des Martyrs, BP 220, F-38043 Grenoble CEDEX, France

Table 3.1.1.1 | top | pdf |
Survey of crystallization techniques suitable for the crystallization of low-molecular-weight organic compounds for X-ray crystallography (adapted from van der Sluis, Hezemans & Kroon, 1989)

Technique	Advantage(s)	Limitation(s)
Evaporation from a single solvent	Simple Inexpensive	Limitation to solvents with adequate vapour pressure Crust formation on tube walls Crystals that are dried are less suitable as seeds, may lose included solvent and become tightly adhered to the crystallization vessel Difficult to reproduce Limited number of solvents give concentration 5–200 mg ml⁻¹ for a particular compound
Evaporation from a binary mixture of solvents (volatile solvent and non-volatile precipitant)	No crust formation on the tube walls Crystals are not dried	Stringent demands on solubility, miscibility and volatility of the two solvents Difficult to reproduce
Batch crystallization	No demands on the volatility of the solvent or precipitant Repeated seeding by thermal treatment is easy	Metastable zone with regard to supersaturation must be large High and almost uncontrollable crystallization rate Solvents must be miscible
Liquid–liquid diffusion	Favourable change in supersaturation at the interface during crystallization Repeated seeding by thermal treatment is easy	Density differences required for the two liquids (less stringent if capillaries are used) Viscosity of the liquids greater than water Solvents must be miscible High and almost uncontrollable crystallization rate
Sitting-drop vapour-phase diffusion	Crystallization rate can easily be controlled by changing the diffusion path, solvent, precipitant, or pH Repeated seeding easily implemented Highest number of independent variables to obtain wide variety of conditions	Solvents must be miscible Solvent preferably less volatile than precipitant
Hanging-drop vapour-phase diffusion	Crystallization rate can easily be controlled by changing solvent, precipitant, or pH Easy examination of crystallization outcome in array-like set-up	Only applicable in case of water-based solvents Diffusion rate is fast and difficult to control See previous method
Temperature change	Easily controllable parameter Repeated seeding extremely easily and accurately carried out With Dewar flask inexpensive and simple	Limited to thermally stable compounds and (pseudo)polymorphs
Gel crystallization	Suited for sparingly soluble or easily nucleating compounds	Limited variety of solvents possible Sampling of crystals difficult Laborious
Sublimation	No inclusion of solvent of crystallization	Limited to small hydrophobic molecules Laborious
Solidification	For liquids and gases the only applicable method	Limited to thermostable compounds High change of amorphicity Laborious