Single-Crystal to Single-Crystal Transformation of a 0D Cu(II) Metallocycle into a 1D Coordination Polymer Triggered by Spontaneous Desolvation in Mother Liquor

<p>A novel Cu(II) imidazolyl-based metallocycle, [Cu2L12(NO3)4]·2MeCN, undergoes a single-crystal to single-crystal transformation to form a 1D coordination polymer, [CuL1(NO3)2]n. This transformation is triggered by the loss of solvent in the presence of the same solvent, which is counterintuitive. Expulsion of interstitial solvent molecules occurs with concomitant rearrangement of the ligands, which concertedly recoordinate to nearby metal centers to achieve a lower energy state. This is the first imidazolyl-based metallacycle reported to undergo such a phase transformation. © 2023 The Authors. Published by American Chemical Society.</p>