2,3,6,7,10,11-Hexahydroxytriphenylene tetrahydrate: a new form of an important starting material for supramolecular chemistry and covalent organic frameworks

Abstract

In the title compound, C18H12O6·4H2O, the 2,3,6,7,10,11‐hexahydroxytriphenylene molecule is located on a twofold axis and two water molecules occupy general positions. The compound forms (4,4) two‐dimensional nets via hydrogen bonds between neighbouring hexahydroxytriphenylene molecules, somewhat similar to the cyclopentanone solvates but distinctively different from the monohydrate form. Hydrogen bonds to water molecules connect these layers to form a complicated three‐dimensional net, supported also by strong π–π stacking.

Achieving Amorphous Ultralong Room Temperature Phosphorescence by Coassembling Planar Small Organic Molecules with Polyvinyl Alcohol

“…It is well known that carbazole molecules have planar conformation that prevents them to generate brightness emission in the solid state, while such planar molecules are easy to give strong emission in the solution state . The single crystal structures of compounds 2, 3, and 8 were determined by us, and the crystal data of other compounds were adopted from literature for the conformation analysis.…”

“…The AIE property suggests that the molecule is easy to consume the excitation energy through the vibration and rotation of the molecule in dilute film system, which is not conducive to produce the stable triplet state. For the large π conjugated planar molecule 11, it exhibited obvious green UOP emission (Figure e and Figure S19 (Supporting Information)) with the quantum yield of 0.5%. For classic AIE molecule 12 also having four benzene rings, it did not emit any UOP from the coassembly state (Figure f and Figure S20 (Supporting Information)), because its distorted conformation inevitably dissipated the triplet excitation energy in dilute state.…”

Structural investigation of a hydrogen bond order–disorder transition in a polar one-dimensional confined ice

“…As in all known HHTP cocrystals, the structure of this hydrate [shown in Fig. 1(b)] is dominated by the stacking of triphenylene cores into 1D columns; 19,20,24 indeed this motif reflects the wellknown role of triphenylene as the structural basis for a large and separate family of discotic liquid crystals. 25 The surface of these columns is decorated by hydrophilic -OH groups, and consequently the voids between columns are ideally suited to water coordination.…”

“…1]. 20 We show that 1D water-filled channels within HHTPÁ4H 2 O exhibit a well-defined polar 2 paraelectric transition; as such the material is an excellent candidate for investigation into ice-based ferroelectric responses. HHTPcontaining systems are of intense current interest in the field of molecular framework materials, where they are favoured for their thermal robustness and attractive porosity/sorption properties.…”

“…In the single previous structural study of HHTPÁ 4H 2 O, it was shown that H 2 O molecules contained within these voids form an elaborate hydrogen-bonding network. 20 Moreover, the water connectivity is one-dimensional such that the system can reasonably be considered a molecularly-confined 1D ice [ Fig. 1(c)].…”