Semicontinuous Temperature Cycle-Induced Deracemization Using an Axially Chiral Naphthamide

This study outlines a practical, semicontinuous method for temperature cycle-induced deracemization (TCID) using a batch-mode crystallizer. We employed an axially chiral naphthamide derivative as a model compound and deracemized the crystalline phase by conventional TCID. To achieve continuity of deracemization, we harvested a part of the suspension after the conventional TCID, and then we fed a new racemic suspension into the enriched suspension and applied temperature cycles. By leaving a highly enriched crystalline phase as seed crystals to direct the chirality of the following enrichment, the enrichment process was significantly accelerated, verifying a stable and high production efficiency. Furthermore, from the perspective of process productivity, the moderate suspension density is optimal for efficient deracemization. In the naphthamide system, up to 7.71 g·L–1·h–1 of productivity was achieved. Thanks to the simple operation, the method described here is applicable for most batch-mode deracemizations reported to date. In terms of industrial applications, semicontinuous deracemization could be a good option to utilize the existing batch-mode crystallizers

Synthesis of Directly and Doubly Linked Dioxoisobacteriochlorin Dimers

Synthesis of Directly and Doubly Linked Dioxoisobacteriochlorin Dimer

Synthesis of Directly and Doubly Linked Dioxoisobacteriochlorin Dimers

Synthesis of Directly and Doubly Linked Dioxoisobacteriochlorin Dimer

Synthesis of Directly and Doubly Linked Dioxoisobacteriochlorin Dimers

Synthesis of Directly and Doubly Linked Dioxoisobacteriochlorin Dimer

Conformational Polymorphism of Octadehydrodibenzo[12]annulene with Dimethyl Phthalate Moieties

In this study, we found that an octadehydrodibenzo[12]annulene derivative with two dimethyl phthalate moieties yielded three polymorphic crystals I, II, and III, in which the annulene core arranges in herringbone, parallel-π-stacked, and zigzag-π-stacked fashion, respectively. This is the first example for dehydroannulenes to show polymorphic crystal structures. These polymorphs are brought from varied conformations of the dimethyl phthalate moieties because the direction of the carbonyl oxygen atoms in the phthalate affects the manner of CH/O interaction abundantly observed in the present systems. It is also revealed that the decomposition temperature of the polymorphic crystals varied over a wide range of values (112−163 °C), even though the crystals are composed of an identical molecule. This indicates that the molecular arrangement might have significant influence on the thermal stability and/or intermolecular reactivity of the annulene

Conformational Polymorphism of Octadehydrodibenzo[12]annulene with Dimethyl Phthalate Moieties

In this study, we found that an octadehydrodibenzo[12]annulene derivative with two dimethyl phthalate moieties yielded three polymorphic crystals I, II, and III, in which the annulene core arranges in herringbone, parallel-π-stacked, and zigzag-π-stacked fashion, respectively. This is the first example for dehydroannulenes to show polymorphic crystal structures. These polymorphs are brought from varied conformations of the dimethyl phthalate moieties because the direction of the carbonyl oxygen atoms in the phthalate affects the manner of CH/O interaction abundantly observed in the present systems. It is also revealed that the decomposition temperature of the polymorphic crystals varied over a wide range of values (112−163 °C), even though the crystals are composed of an identical molecule. This indicates that the molecular arrangement might have significant influence on the thermal stability and/or intermolecular reactivity of the annulene

Conformational Polymorphism of Octadehydrodibenzo[12]annulene with Dimethyl Phthalate Moieties

In this study, we found that an octadehydrodibenzo[12]annulene derivative with two dimethyl phthalate moieties yielded three polymorphic crystals I, II, and III, in which the annulene core arranges in herringbone, parallel-π-stacked, and zigzag-π-stacked fashion, respectively. This is the first example for dehydroannulenes to show polymorphic crystal structures. These polymorphs are brought from varied conformations of the dimethyl phthalate moieties because the direction of the carbonyl oxygen atoms in the phthalate affects the manner of CH/O interaction abundantly observed in the present systems. It is also revealed that the decomposition temperature of the polymorphic crystals varied over a wide range of values (112−163 °C), even though the crystals are composed of an identical molecule. This indicates that the molecular arrangement might have significant influence on the thermal stability and/or intermolecular reactivity of the annulene

A Hydrogen-Bonded, Hexagonally Networked, Layered Framework with Large Aperture Designed by Structural Synchronization of a Macrocycle and Supramolecular Synthon

To develop porous organic frameworks, precise control of the stacking manner of two-dimensional porous motifs and structural characterization of the resultant framework are important. From these points of view, porous molecular crystals formed through reversible intermolecular hydrogen bonds, such as hydrogen-bonded organic frameworks (HOFs), can provide deep insight because of their high crystallinity, affording single-crystalline X-ray diffraction analysis. In this study, we demonstrate that the stacking manner of hydrogen-bonded hexagonal network (HexNet) sheets can be controlled by synchronizing a homological triangular macrocyclic tecton and a hydrogen-bonded cyclic supramolecular synthon called the phenylene triangle. A structure of the resultant HOF was crystallographically characterized and revealed to have a large channel aperture of 2.4 nm. The HOF also shows thermal stability up to 290 °C, which is higher than that of the conventional HexNet frameworks

Anomalous Anthracene Arrangement and Rare Excimer Emission in the Solid State: Transcription and Translation of Molecular Information

A novel molecular arrangement of anthracene moieties and the corresponding rare solid-state excimer emission is obtained by utilization of a ternary system. The system consists of ammonium anthracene disulfonate and adducts, and shows the modulation of the solid-state emission mode depending on the adducts. The adducts act as molecular information sources that are transcribed to the arrangement, and the arrangement is translated into the emission mode. This series of processes might be mimicry of central dogma