The Preparation of Heptacyclo[6.6.0.0.2,60.3,130.4,11 0.5,90.10,14]Tetradecane Derivatives and the Analysis of Their NMR Spectra

The title compound is functionalized by a series of reactions to yield derivatives in the forms of hydroxides, ketones, ketals, lactones, etc. Their structures are analyzed by NMR spectroscopy.     

Dipotassium maleate with boric acid

In the title compound, poly[(μ₃‐boric acid)‐μ₄‐maleato‐dipotassium], [K₂(C₄H₂O₄){B(OH)₃}]_n, there are two independent K⁺ cations, one bonded to seven O atoms (three from boric acid and four from maleate), and the other eight‐coordinate via three boric acid and four maleate O atoms and a weak η¹‐type coordination to the C=C bond of the maleate central C atoms. Hydrogen bonding links the boric acid ligands and maleate dianions, completing the packing structure.     

Helicenes as All‐in‐One Organic Materials for Application in OLEDs: Synthesis and Diverse Applications of Carbo‐ and Aza[5]helical Diamines

A set of eight helical diamines were designed and synthesized to demonstrate their relevance as all‐in‐one materials for multifarious applications in organic light‐emitting diodes (OLEDs), that is, as hole‐transporting materials (HTMs), EMs, bifunctional hole transporting + emissive materials, and host materials. Azahelical diamines function very well as HTMs. Indeed, with high T_g values (127–214 °C), they are superior alternatives to popular N,N′‐di(1‐naphthyl)‐N,N′‐diphenyl‐(1,1′‐biphenyl)‐4,4′‐diamine (NPB). All the helical diamines exhibit emissive properties when employed in nondoped as well as doped devices, the performance characteristics being superior in the latter. One of the carbohelical diamines (CHTPA) serves the dual function of hole transport as well as emission in simple double‐layer devices; the efficiencies observed were better by quite some margin than those of other emissive helicenes reported. The twisting endows helical diamines with significantly high triplet energies such that they also function as host materials for red and green phosphors, that is, [Ir(btp)₂acac] (btp=2‐(2′‐benzothienyl)pyridine; acac=acetylacetonate) and [Ir(ppy)₃] (ppy=2‐phenylpyridine), respectively. The results of device fabrications demonstrate how helicity/ helical scaffold may be diligently exploited to create molecular systems for maneuvering diverse applications in OLEDs.     

Synthesis of Stable Sulfonium Ylides from Sulfoxides and Dimethyl Acetylenedicarboxylate

Stable sulfonium ylides are readily prepared from thermolysis of dimethyl-, dibenzyl-, dibutyl-, and diphenyl- sulfoxides with dimethyl acetylenedicarboxylate in reasonable yields.     

Synthesis of Isodrin Homologues with Parallel-Aligned Double Bonds

A formal synthesis of an alcohol 6 (X = OH) possessing three parallel-aligned double bonds was accomplished starting from 7 through thirteen steps in an optimal yield of 10%.     

The Bonding Structure of Quadricyclanylidene Derivatives

The crystal structures of bisquadricyclanylidene 1 , 7‐quadricyclanylidenenorbornadienes 2 and 3 are solved by X‐ray diffraction analyses. The bond lengths of the cyclopropyl moieties of 1 , 2 and 3 are compared with several other quadricyclanylidene derivatives, and the differences are analyzed by computational models. The results showed that the variation of bond lengths in this series of compounds is related to the electronic nature of substituents.     

Photoinduced electron transfer reaction tuned by donor-acceptor pairs via the rigid, linear spacer heptacyclo[6.6.0.0.0.0.0.0]tetradecane

A new class of donor-{saturated hydrocarbon bridge}-acceptor (D-B-A) dyads were synthesized and utilized on a systematic approach to evaluate the corresponding photoinduced electron transfer (ET) process. Among these dyads heptacyclo[6.6.0.0^2,6.0^3,13.0^4,11. 0^5,9.0^10,14]tetradecane (HCTD) was used as a unique spacer, which possesses a geometry of high symmetry (D_2d), rigidity and linearity. The spectroscopy and dynamics of excited-state ET as functions of donor/acceptor electronic states, orientation as well as solvent properties were analyzed with the aid of theoretical computations. It was observed that the quenching of donor fluorescence (the F₁ band) correlated with the appearance of a broad charge-transfer (CT) emission. Both wavelength and intensity of the CT band varied with solvent-polarity, whereas its rise dynamics complied well with the decay of the F₁ band. In acetonitrile, the CT state decays much faster than the rate of ET (∼63 ps⁻¹) so that the corresponding steady-state emission cannot be resolved. An intriguing effect was observed in the case of benzene-1,2-dithioketals (3a and 3b) where the D and A π-chromophores were aligned in different orientations. The estimated ET rate of 3a (3.9×10¹⁰ s⁻¹) was substantially faster than that of 3b (7×10⁸ s⁻¹). The experimental data were tentatively fitted by a semi-log plot of ET rate constants (k_et) against free energy (ΔG⁰), yielding a value of ∼17.3 cm⁻¹ for the electron-coupling matrix (H_el).     

On Finite Model Property for Admissible Rules

Our investigation is concerned with the finite model property (fmp) with respect to admissible rules. We establish general sufficient conditions for absence of fmp w. r. t. admissibility which are applicable to modal logics containing K4: Theorem 3.1 says that no logic λ containing K4 with the co-cover property and of width > 2 has fmp w. r. t. admissibility. Surprisingly many, if not to say all, important modal logics of width > 2 are within the scope of this theorem–K4 itself, S4, GL, K4.1, K4.2, S4.1, S4.2, GL.2, etc. Thus the situation is completely opposite to the case of the ordinary fmp–the absolute majority of important logics have fmp, but not with respect to admissibility. As regards logics of width ≤ 2, there exists a zone for fmp w. r. t. admissibility. It is shown (Theorem 4.3) that all modal logics A of width ≤ 2 extending S4 which are not sub-logics of three special tabular logics (which is equipotent to all these λ extend a certain subframe logic defined over S4 by omission of four special frames) have fmp w.r.t. admissibility.     

N‐(p‐Chloro­phenyl)‐3,3‐di­phenyl‐4‐(β‐phenyl­styryl)azetidin‐2‐one

In the title compound, C₃₅H₂₆ClNO, the four‐membered β‐lactam ring is essentially planar, with a maximum deviation of 0.012 (1) Å for the N atom. The C—C bond lengths in the β‐lactam ring are 1.591 (2) and 1.549 (2) Å. The two phenyl rings attached to the β‐lactam ring are nearly perpendicular to each other [83.2 (1)°].