Synthesis and Optical Properties of Axially Chiral Bibenzo[ b]carbazole Derivatives

Pure organic materials with the circularly polarized luminescence (CPL) property have attracted significant research interest over the past few decades. In this study, a series of axially chiral bibenzo[b]carbazole derivatives were synthesized by adopting palladium- and iridium-catalyzed direct C–H functionalization reactions as the key steps. These compounds exhibited CPL characteristics with considerably large dissymmetry factors up to 2.81 × 10–2 in the solid state, indicating the formation of well-ordered aggregates.Takishima R., Nishii Y., Miura M.. Synthesis and Optical Properties of Axially Chiral Bibenzo[ b]carbazole Derivatives. Organic Letters. 23(4), 1349-1354, (2021); 19 February 2021: ©2021 American Chemical Society. https://doi.org/10.1021/acs.orglett.1c00011

Synthesis and circularly polarized luminescence properties of BINOL-derived bisbenzofuro[2,3-b:3′,2′-e]pyridines (BBZFPys)

A series of optically active bisbenzofuro[2,3-b:3′,2′-e]pyridine (BBZFPy) derivatives was synthesized starting with the readily available (S)- and (R)-1,1′-bi-2-naphthols through a palladium-catalyzed multiple intramolecular C-H/C-H coupling as the key ring-closure step. The effect of terminal tert-butyl substituents on the BBZFPy skeleton was systematically investigated to uncover a unique aggregation-induced enhancement of CPL characteristics in the solid state. The crystal structures of the coupling products were also evaluated by single crystal X-ray analysis and the well-ordered intermolecular stacking arrangements appeared to be responsible for the enhanced CPL.Beilstein J. Org. Chem. 2020, 16, 325–336. doi:10.3762/bjoc.16.3

Predicting the solubilities of metal acetylacetonates in supercritical CO2: Thermodynamic approach using PC-SAFT

Solubilities of metal precursors in supercritical carbon dioxide (scCO2) are needed to effectively design the scCO2-based deposition method. Herein, a method for predicting the solubilities of metal acetylacetonate (acac) precursors in scCO2 was developed using the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state. Three PC-SAFT pure-component parameters viz., the segment diameter, segment number, and dispersion energy, for two metal acetylacetonates (Cr(acac)3 and Cu(acac)2) were determined by adjusting their values to the measured solubilities in organic solvents. The PC-SAFT parameters of Cr(acac)3 and Cu(acac)2 were then applied to predict the experimentally determined metal precursor solubilities in scCO2 from the literature. The PC-SAFT predictions accurately described the experimental solubilities in scCO2 over a wide range of pressures and temperatures even if the binary interaction parameter kij was set to 0. The isobaric solubilities in scCO2 were also calculated with the generalized kij values, which provided a successful PC-SAFT description.This work was supported by a JSPS (Japan Society for the Promotion of Science)KAKENHI Grant-in-Aid for Scientific Research [grant number 18K14045]

Synthesis and Optical Properties of Axially Chiral Bibenzo[ b]carbazole Derivatives

Takishima R., Nishii Y., Miura M.. Synthesis and Optical Properties of Axially Chiral Bibenzo[ b]carbazole Derivatives. Organic Letters. 23(4), 1349-1354, (2021); 19 February 2021: ©2021 American Chemical Society. https://doi.org/10.1021/acs.orglett.1c00011.Pure organic materials with the circularly polarized luminescence (CPL) property have attracted significant research interest over the past few decades. In this study, a series of axially chiral bibenzo[b]carbazole derivatives were synthesized by adopting palladium- and iridium-catalyzed direct C–H functionalization reactions as the key steps. These compounds exhibited CPL characteristics with considerably large dissymmetry factors up to 2.81 × 10–2 in the solid state, indicating the formation of well-ordered aggregates