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A series of heterobimetallic (Au⋯Ag interlocking and Au⋯Cu interlocking) [2]catenanes were studied using DFT and TD-DFT methods to explore the relationship between their structures and properties. In order to fully investigate the influence of metal type in these [2]catenanes and compare the similarities and differences between these heterobimetallic and homometallic catenanes, the results were also compared with our previously studied homometallic Au⋯Au interlocking [2]catenane molecules. The results display that the steric hindrance increases with the increase of the number of monomers, and thus the distances between the center and the edge of the rings become longer, demonstrating a trend of outward expansion. As the size of the ring becomes larger, the total weak interaction increases and shows increasingly dispersed distribution. The value of the dispersion interaction energy increases with the overgrowth of the size of molecular systems and correspondingly the energy level of the frontier orbital decreases and the energy gap becomes bigger when two hexamers interlock. Compared with the Au⋯Ag interlocking [2]catenanes, the Au⋯Cu interlocking [2]catenanes present red-shifted absorption spectra, which is consistent with their smaller energy gap. The hole–electron analysis results indicate that the S0 → S1 excitations are almost unidirectional charge transfer excitations due to the significant separation of holes and electrons, while for the high-energy excited states, local excitations occupy a dominant position. Through the study of the specific proportion of charge transfer on each fragment in the main transition process, we found that for heterometallic [2]catenanes, the Cu atom in the Au⋯Cu interlocking [2]catenanes has a greater influence on the electronic structure. As for homometallic [2]catenanes, the effects of Au atoms in the two rings are equivalent on the electronic structure. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Stability against oxygen is an important factor affecting the performance of organic semiconductor devices. Improving photooxidation stability can prolong the service life of the device and maintain the mechanical and photoelectric properties of the device. Generally, various encapsulation methods from molecular structure to macroscopic device level are used to improve photooxidation stability. Here, we adopted a crystallization strategy to allow 14H‐spiro[dibenzo[c,h]acridine‐7,9′‐fluorene] (SFDBA) to pack tightly to resist fluorescence decay caused by oxidation. In this case, the inert group of SFDBA acts as a "steric armor", protecting the photosensitive group from being attacked by oxygen. Therefore, compared with the fluorescence quenching of SFDBA powder under 2 h of sunlight, SFDBA crystal can maintain its fluorescence emission for more than 8 h under the same conditions. Furthermore, the photoluminescence quantum yields (PLQYs) of the crystalline film is 327% higher than that of the amorphous film. It shows that the crystallization strategy is an effective method to resist oxidation. [ABSTRACT FROM AUTHOR]

6-(4-chlorophenoxy)-tetrazolo[5,1-a]phthalazine is a national class I innovative antiepileptic drug candidate in clinical trials with independent intellectual property rights. The 1H, 13C and 15N NMR spectra of the compound were acquired at 500 MHz. Aided by GIAO (Gauge-Independent Atomic Orbital)-NMR quantum chemistry calculation, the chemical shifts of the compound were assigned, providing elaborate structural information of the compound. Linear regression comparison results showed good consistency between the theoretical predictions and the experimental data for structural elucidations.

Crystallization of organic steric molecules often leads to multiple polyhedral crystal morphologies. However, the relationships among the molecular structure, supramolecular interaction, aggregation mode and crystal morphology are still unclear. In this work, we elaborate two model crystals formed by spiro[fluorene‐9,9′‐xanthene] (SFX) and spiro[cyclopenta[1,2‐b : 5,4‐b′]dipyridine‐5,9′‐xanthene] (SDAFX) to demonstrate the feasibility of morphology prediction by periodic bond chain (PBC) theory based on interaction energy (IE) values in terms of single point energy. With non‐directional van der Waals forces, only one PBC direction is found in SFX crystal, leading to the irregular 1D rod‐like structure. Compared with SFX, the extra N heteroatoms in SDAFX can bring additional hydrogen bonds and some other interactions into the bulky molecular skeletons, inducing 3‐dimensionally oriented PBCs to form the explicit F‐face network in SDAFX which leads to the final octahedral structure. A simple and accurate method has been provided to quantify PBC vector on the supramolecular level in the organic molecular system, and the PBC theory has also been further demonstrated and developed in the morphology prediction of organic spiro‐molecules. [ABSTRACT FROM AUTHOR]

A novel barium(II) coordination polymer (CP), [Ba3(L)2(H2O)4]n1, has been firstly isolated based on organic ligand 1‐[(2′‐carboxybiphenyl‐4‐yl)methyl]‐2‐propylimidazole‐4,5‐dicarboxylic acid (H3L=(HO2C)2(C3N2)(C3H7)CH2(C6H4)(C6H3)CO2H) by hydrothermal technique, and determined by single‐crystal X‐ray diffractions, elemental analysis, IR, powder X‐ray diffractions (PXRD). The Ba(II)‐CP 1 belongs to a novel 2‐D layer structure created from 1‐D serrated chain containing secondary building unit (SBU) [Ba(1)Ba(2)Ba(3)] via carboxylate group linkage. In 1, the ligand L3− gives a variety of coordinated styles, nonadentate: μ2:(η1η1), μ2:(η1η1), μ3:(η2η2) and decadentate: μ1:(η1η1), μ3:(η2η2), μ3:(η1η2), μ3:(η1η2), which is the first reported example. Moreover, the room‐temperature fluorescent measurements show that the Ba(II)‐CP 1 has specific ability to recognize copper(II) ion in aqueous solution by means of fluorescence quenching effect, corresponding obtained quenching constant Ksv=1.18×102 M−1 and the limit of detection LOD=0.274 μM. Fluorescence titration experiment reveals that there is a good linear relationship between copper ion concentration and fluorescence intensity in the concentration range of 2.0×10−6∼5.3×10−6 mol ⋅ L−1. The corresponding linear equation: y=402.41897–0.70486x, and linear correlation coefficient: R2=0.99866 (λex=310 nm and λem=412 nm). [ABSTRACT FROM AUTHOR]