Introduction
X-ray quality single crystals have to exhibits a high degree of internal order as evidence by the presence of an X-ray diffraction pattern and reaches in size between 0.1 - 0.4 mm in at least two of the three dimensions. The CrystalBreeder helps you set up crystallization experiments in parallel using different conditions and maximize your chance of success in a relatively short time. For growing single crystals, avoid solvents in which your compound forms supersaturated solutions and too many nucleation sites will implicitly lower the crystal size, and therefore working with clean glassware is important. The 0.3 mL glass vials of the CrystalBreeder have the same diameter and aspect as standard NMR tubes and helps you to perform the experiments in a disruption free environment.
Thermal crystallization for growing single crystal with the CrystalBreeder
Crystal of carbamazepine (CBZ) and p-aminobenzoic acid were grown by thermal crystallization at 0.1 ml scale.
Excellent quality crystals were obtained for two forms of carbamazepine. The anhydrate of carbamazepine (CBZ) crystallizes as thin needles (monoclinc P21/n). The hydrated form of carbamazepine (CBZ·0.25H2O) crystallizes as prismatic crystals (trigonal R-3). Whereas, P-aminobenzoic acid crystals showed to have a monoclinic symmetry crystallizing in P21/n space group (Figure 1).
Figure 1: Crystallization results of carbamazepine in 0.1 mL 2-propanol (left) and in THF (right)
Sublimation for growing single crystal with the CrystalBreeder
Single crystals of diphenic acid were grown by sublimation. Approx. 1 mg of the compound was transferred into a 0.3 ml vial and heated to 150°C. Vapour deposition of diphenic acid in the form of single crystals occurred within few hours, resulting in crystals suitable for single crystal structure determination. By applying vacuum (150 mbar) the process was not only accelerated, but also better-quality crystals were obtained (Figure 2). Similarly, sublimation experiments lead to single crystals of salicylamide and salicylic acid (Figure 3).
Figure 2: Sublimation experiment results of diphenic acid: (left) performed at 150°C using vacuum (150 mbar), (right) the same experiment without vacuum.
Figure 3: Sublimation experiment results of (left) salicylamide and (right) salicylic acid.
Curious to learn more?
Read the full application note "Growing X-ray quality single crystals".