ABSTRACT
The mol-ecule of the title compound, C16H14N2O, contains an essentially planar indole ring system and a phenyl ring. In the crystal, the mol-ecules are linked by a weak inter-molecular C-Hâ¯O hydrogen bond and C-Hâ¯π inter-actions, forming a one-dimensional column structure along the b-axis direction. These columns are linked by other C-Hâ¯π inter-actions, forming a two-dimensional network structure.
ABSTRACT
Partially overlapped dicarbazolophanes exhibit a planar chirality. In this study, C2-symmetrical [3.3](3,9)dicarbazolophane derivatives (CZ1-CZ3) have been optically resolved by preparative chiral high-performance liquid chromatography for the first time. In their circular dichroism (CD) spectra, moderate Cotton effects (CEs) were observed for their 1Lb and 1La transitions (|Δε| = 10-12 and 51-57 M-1 cm-1, respectively), while intense CEs were notified in their 1B transitions (|Δε| = 156-216 M-1 cm-1), absorption dissymmetry (gabs) factors being in orders of 10-2. Circularly polarized luminescence spectrum was also obtained for cyanamide derivative CZ1, with a comparative luminescence dissymmetry (glum) factor of 0.013. A computational investigation was applied to address the factors for such remarkable chiroptical responses in these dicarbazolophanes of planar chirality. Absolute configurations were unambiguously determined by the comparison of experimental and theoretical CD spectra, which was affirmed by the X-ray crystal structural analysis of enantiomerically pure sulfonamide derivative CZ2.
ABSTRACT
In the title compound, C27H29BrN2, the carbazole ring system is essentially planar, with an r.m.s. deviation of 0.0781â (16)â Å. An intra-molecular N-Hâ¯N hydrogen bond forms an S(6) ring motif. One of the tert-butyl substituents shows rotational disorder over two sites with occupancies of 0.592â (3) and 0.408â (3). In the crystal, two mol-ecules are associated into an inversion dimer through a pair of C-Hâ¯π inter-actions. The dimers are further linked by another pair of C-Hâ¯π inter-actions, forming a ribbon along the c-axis direction. A C-Hâ¯π inter-action involving the minor disordered component and the carbazole ring system links the ribbons, generating a network sheet parallel to (100).
ABSTRACT
A trigonal donor-acceptor molecule of 1,3,5-tris(4-(diphenylamino)phenyl)-2,4,6-tricyanobenzene (3DPA3CN) was synthesized to exhibit efficient thermally activated delayed fluorescence. By doping 3DPA3CN into a wide energy gap host, the film had a photoluminescence quantum efficiency of 100% with the reverse intersystem crossing efficiency of 100%. An OLED including the emitter exhibited a very high external quantum efficiency (η(EQE)) of 21.4%.
ABSTRACT
4,4[prime or minute]-Methylenebis(N-salicylidene-2,6-dialkylaniline) derivatives were prepared and their structures were determined by (1)H NMR, IR, DSC and X-ray crystallographic analyses. The 2,6-diisopropylaniline derivative yielded definite polymorphic crystals: the space groups of the crystals were C2/c and P2(1)/n, respectively. It was found that both polymorphs were similarly photochromic but the thermal stability of the photochrome was different due to the variance of the shape of molecule and cavity in each crystal.