Single crystal to single crystal polymorphic phase transition of a silver nitrate 24-crown-8 complex and its pseudo-polymorphism

Abstract

A silver nitrate 24-crown-8 complex [Ag₄(24-crown-8)(NO₃)₄] (1) was synthesized, showing a single crystal to single crystal polymorphic phase transition induced by temperature and leading to polymorph [Ag₄(24-crown-8)(NO₃)₄] 1′. When this complex (1) is exposed to humidity or directly crystallized from a water containing solvent, a pseudo polymorph [Ag₄(24-crown-8)(NO₃)₄(H₂O)₂] (2) with two additional water molecules is obtained. When this pseudo polymorph is heated above 100° C, it may be transformed back into the first structure (1).