Controlled Reversible Crystal Transformation of Cu(I) Supramolecular Isomers

Abstract

Four copper(I) coordination polymers (CPs), {[CuIL]·CH3CN]} n (1), {[CuIL]·CHCl3} n (2), {[CuIL]·CH2Cl2} n (3), and [CuIL] n (4), were prepared by self-assembly reactions between CuI and (2-pyrazinylcarbonyl)thiomorpholine (L). CPs 1–4 are interconnected by rhomboid Cu–I2–Cu units. CPs 1 and 4 have one-dimensional loop-chain structures, and 2 and 3 adopt two-dimensional network structures. CPs 1–4 are pseudopolymorphic supramolecular isomers. CPs 2′ and 3′ are prepared by removal of solvate molecules from CPs 2 and 3, which are polymorphic supramolecular isomers with CP 4. Reversible crystal-to-crystal transformations were observed under appropriate conditions such as solvent or heat.

Exploring the crystallization landscape of cadmium bis(N-hydroxyethyl, N-isopropyldithiocarbamate), Cd[S2CN(iPr)CH2CH2OH]2

“…Examples exist whereby reversible single crystal single crystal transformations mediated by solvent guests [90,91], recrystallization [92] and microwave irradiation/rehydration [93,94]. (7) it was concluded that adventitious water mediated the in situ transformation of 6 to 7 [50].…”

Photoluminescent Copper(I) Complex Based on 3‐(2‐(Cyclohexylthio)ethoxy)pyridine: Synthesis, Structure, and Physical Properties

“…[10][11][12] Luminescence thermochromism 13 and mechanochromism 14 of copper(I) complexes have been studied. Recently, we have concentrated on our research about Cu(I) coordination polymers based on dithioether ligands [15][16][17] and reported on luminescence thermochromism, 15 preparation of γ-CuI nanoparticle, 18 crystal-to-crystal transformation, 19 and so on. During our investigation on the copper(I) complexes of dithioether ligands, no photoluminescence was observed from rhomboid Cu 2 I 2 complexes.…”

Reversible Luminescence Vapochromism and Crystal-to-Amorphous-to-Crystal Transformations of Pseudopolymorphic Cu(I) Coordination Polymers

“…Acetonitrile played a key role in solvent exchange by opening the space inside the CP framework, and although reversible transformation was seen, crystal transformation based on solvent vapor was not observed. 16 We therefore chose to investigate the possibility of reversible crystal transformations induced by volatile organic compound (VOC) vapors by employing ligand conformation change and crystal-to-amorphous-to-crystal (CAC) transformations, according to stepwise stimulation by heat and solvent vapors. 18−21 A dithioether ligand, N,N′-bis [2-(cyclohexylthio)ethyl] pyromellitic diimide (L), bearing an electron-deficient pyromellitic diimide spacer was synthesized by reacting pyromellitic dianhydride with 2-(cyclohexylthio)ethylamine according to a previous literature method.…”

“…As shown in Figure 2b, CPs 1−3 showed reversible solvent exchange according to the specific ratios of VOC vapors, and as a result, transformation between the crystals occurred more readily. 16,23 We investigated whether powdered specimens of CPs 1−3 exhibited vapochromism when coated on a glass slide (left to right) and exposed to a mixed solvent vapor with a specific ratio at room temperature ( Figure S9 in the SI). 24,25 When the prepared specimens were exposed to the vapor of a dichloromethane/acetonitrile 5:1 mixture, CPs 2 and 3 exhibited comparable luminescence with CP 1, thus being in accord with solvent exchange using dichloromethane and structural transformation from CPs 2 and 3 to CP 1.…”