单晶培养讲义 Growing Crystals That Will Make Your Crystallographer Happy.pdf

Growing Crystals That Will Make Your Crystallographer Happy Paul D. Boyle Department of Chemistry North Carolina State University Box 8204 Raleigh, NC, 27695 (NOTE: This article is also accessible on the World Wide Web at /GrowXtal.html) with contributions from: Clarence Pfluger (cpfluger@); Anthony Linden (alinden@oci.unizh.ch); Chuck Barnes (chemclb@); Andrea Sella (a.sella@ucl.ac.uk) Contents • The Goal • General Considerations ❏ Solvent ❏ Nucleation ❏ Mechanics ❏ Time • Techniques ❏ Slow Evaporation ❏ Slow Cooling ❏ Variations on Slow Evaporation and Slow Cooling ❏ Vapor Diffusion ❏ Solvent Diffusion ❏ Reactant Diffusion ❏ Sublimation ❏ Convection ❏ Co-crystallants ❏ Counterions ❏ Ionization of Neutral Compounds • References Growing Crystals That Will Make Your Crystallographer Happy 2 Practically every chemist knows the necessity of recrystallization as a method of purification. What is less well known, however, is methods by which “X-ray quality” crystals may be obtained. The purpose of this monograph is to briefly and informally outline some of the methods which can be used to obtain single crystals suitable for X-ray diffraction studies. This monograph is meant neither to be rigorous nor exhaustive, but rather, a sort of practical “how to” cookbook. A good general reference which covers similar material can be found in “Crystal Growing”, Chemistry in Britain 1981, 17, 222–225 by Peter G. Jones. The Goal The goal in growing crystals for a single crystal X-ray diffraction experiment is to grow single crystals (obviously) of suitable size. The optimum size for a crystal is one which