Dimensionality Changes in Crystalline Complexes Induced by Exposure to Air: Solid-State Studies Using Single Crystal and Powder X-ray Diffraction Methods

Abstract

When they come into contact with air, coordination compounds can often change their appearance. For instance, the colour of the compound can change as transparent crystals become opaque microcrystalline solids. This visible transformation of the compound is frequently accompanied by structural modifications due to loss of solvent molecules or in the reverse case, the reaction with water from the air. Often, the dimensionality of the structures also varies and this aspect is demonstrated for three pairs of copper(II) complexes (1D ? 0D, 1D ? 2D and 3D ? 2D). The complementary use of single crystal and powder X-ray diffraction methods is indispensable for the evaluation of these structural changes.

Keywords

• Coordination polymers
• Solid-state transformations
• X-ray powder diffraction