High-pressure and temperature dependence of the spontaneous resolution of 1,1′-binaphthyl enantiomers

Abstract

High pressure increases the temperature of the spontaneous resolution of 1,1'-binaphthyl conformational enantiomers in the crystalline state, which confirms that the enantiomers and racemates are stabilized in the molecular environments in compressed structures. The established pressure-temperature (p-T) preference diagram for the racemate-enantiomer spontaneous crystallization corresponds to a boundary between solid phases, as it is consistent with the Clausius-Clapeyron equation, however, the hysteresis of such a solid-state transformation extends to very high pressure, to 3 GPa, at least according to this study. High-pressure X-ray diffraction study on single crystals of 1,1'-binaphthyl racemate and enantiomer reveals their monotonic compression and structural changes up to 3 GPa. It also reveals the increasing role of intermolecular interactions for stabilizing the structures, despite the exceptionally large density difference between the racemate (1.277 g cm) and enantiomers (1.183 g cm).

Iron-Catalyzed Synthesis, Structure, and Photophysical Properties of Tetraarylnaphthidines

“…The structural assignment for N,N,N',N'-tetraphenylnaphthidine (4) was confirmed by an X-ray crystal structure determination ( Figure 3). The molecule of compound 4 adopts a trans conformation around the central biaryl bond (C1-C11) with a torsional angle of 99.4(2)° ( Figure 4) according to the notation accepted for binaphthyl derivatives [27,28]. The geometry of the naphtho fragments exhibiting large variations of the bond lengths is in agreement with the crystal structure of naphthalene [29,30] and its structure obtained by quantum chemical calculations [31].…”

“…The distances between the hydrogen atoms and the sp 2 -carbon atoms range from 2.7 to 2.8 Å and the angles are typical for these weak hydrogen bonds [32]. This sort of packing with face-to-edge interactions has been observed also in naphthalene itself [29,30] and in binaphthyl derivatives [27,28]. It is noteworthy that the naphtho groups interact mostly with each other and the phenyl groups interact predominantly with phenyl groups, whereas naphtho-phenyl contacts are rare.…”

Two Unexpected Temperature-Induced Supermolecular Isomers from Multi-Topic Carboxylic Acid: Hydrogen Bonding Layer or Helix Tube

“…It has been confirmed in a kinetic model that an achiral artificial assembly system could spontaneously produce chirality [33]. However, without inducing the chiral chemical regents (as reactants or template), the coordinated or covalent enantiomers are commonly observed in the spontaneous resolution system [34][35][36][37]. Although 1-H should contain two different enantiomer single crystals, unfortunately, the attempt to pick out and solve the left-helix structure of single-crystal X-ray crystallography failed.…”

Does Pressure Break Mirror‐Image Symmetry? A Perspective and New Insights

“…The system exhibits a high-density difference between the denser racemic compound (1.28 g cm À 1 ) and either enantiomer (1.18 g cm À 1 ), although both racemates show monotonic compression and structural changes up to 3 GPa. [42] Up to this point, the examples highlighted involve crystals and/or solid phases, where pressure could incidentally lead to structural changes in racemates leading to a metastable conglomerate. An intermediate situation can occur in chiral liquid crystals, which show different temperature-dependent phase transitions.…”