Intermolecular interactions-photophysical properties relationships in phenanthrene-9,10-dicarbonitrile assemblies

Phenanthrene-9,10-dicarbonitriles show various luminescence behaviour in solution and in the solid state. Aggregation patterns of phenanthrene-9,10-dicarbonitriles govern their luminescent properties in the solid state. Single crystal structures of phenanthrene-9,10-dicarbonitriles showed head-to-tail intraplane (or quasi-intraplane) intermolecular interactions and π-stacking patterns with eclipsing of molecules when viewed orthogonal to the stacking plane. The π-stacking interactions were detected in the X-ray structures of phenanthrene-9,10-dicarbonitriles and studied by DFT calculations at the M06–2X/6–311++G(d,p) level of theory and topological analysis of the electron density distribution within the framework of QTAIM method. The estimated strength of the C⋯C contacts responsible for the π-stacking interactions is 0.6–1.1 kcal/mol. The orientation of molecules in crystals depends on the substituents in phenanthrene-9,10-dicarbonitriles. Distinct molecular orientation and packing arrangements in crystalline phenanthrene-9,10-dicarbonitriles ensured perturbed electronic communication among the nearest and non-nearest molecules through an interplay of excimer and dipole couplings. As a result, the intermolecular interactions govern the solid state luminescence of molecules

C,N-chelated diaminocarbene platinum(II) complexes derived from 3,4-diaryl-1H-pyrrol-2,5-diimines and cis-dichlorobis(isonitrile)platinum(II):Synthesis, cytotoxicity, and catalytic activity in hydrosilylation reactions

The reaction of 3,4-diaryl-1H-pyrrol-2,5-diimines with cis-dichlorobis(isonitrile)platinum(II) affords the C,N-chelated diaminocarbene platinum(II) complexes, which have been fully characterized including molecular spectroscopy, single crystal X-ray diffraction and DFT calculations. The obtained platinum(II) complexes are effective catalysts for the hydrosilylation of alkynes and alkenes. Thus, the reaction of phenylacetylene with triethoxysilane leads to the formation of α- and β-(E)-vinylsilanes, generating TON's in the range of 103 to 104 and TOF's in the range of 102 to 103 h−1. Also, the cross-linked silicones, possessing the luminescence properties, were obtained by the hydrosilylation reaction of vinyl- and hydride-containing polysiloxanes. Additionally, the efficiency of diaminocarbene platinum(II) complexes against CH1/PA-1, SW480, and A549 cancer cell lines has been demonstrated by in vitro cytotoxicity studies.peerReviewe

Structural data of phenanthrene-9,10-dicarbonitriles

In this data article, we present the single-crystal XRD data of phenanthrene-9,10-dicarbonitriles. Detailed structure analysis and photophysical properties were discussed in our previous study, "Intermolecular interactions-photophysical properties relationships in phenanthrene-9,10-dicarbonitrile assemblies" (Afanasenko et al., 2020). The data include the intra- and intermolecular bond lengths and angles. (c) 2019 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Structures and photophysical properties of 3,4-diaryl-1H-pyrrol-2,5-diimines and 2,3-diarylmaleimides

Structural features of 3,4-diaryl-1H-pyrrol-2,5-diimines and their derivatives have been studied by molecular spectroscopy techniques, single-crystal X-ray diffraction, and DFT calculations. According to the theoretical calculations, the diimino tautomeric form of 3,4-diaryl-1H-pyrrol-2,5-diimines is more stable in solution than the imino-enamino form. We also found that the structurally related 2,3 exist in the solid state in the dimeric diketo form. 3,4-Diary1-1H-pyrrol-2,5-diimines and 2,3-diarylmaleimides exhibit fluorescence in the blue region of the visible spectrum. The fluorescence spectra have large Stokes shifts. Aryl substituents at the 3,4-positions of 1H-pyrrol-2,5-diimine do not significantly affect fluorescence properties. The insertion of donor substituents into 2,3diarylmaleimides leads to bathochromic shift of emission bands with hyperchromic effect. (C) 2017 Elsevier B.V. All rights reserved

Thermal Rearrangement of 5-(2-Hydroxy-6-oxocyclohexyl)-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridines

Some of the most important transformations in organic chemistry are rearrangement reactions, which play a crucial role in increasing synthetic efficiency and molecular complexity. The development of synthetic strategies involving rearrangement reactions, which can accomplish synthetic goals in a very efficient manner, has been an evergreen topic in the synthetic chemistry community. Xanthenes, pyridin-2(1H)-ones, and 1,6-naphthyridines have a wide range of biological activities. In this work, we propose the thermal rearrangement of 7,9-dihalogen-substituted 5-(2-hydroxy-6-oxocyclohexyl)-5H-chromeno[2,3-b]pyridines in DMSO. Previously unknown 5,7-dihalogenated 5-(2,3,4,9-tetrahydro-1H-xanthen-9-yl)-6-oxo-1,6-dihydropyridines and 10-(3,5-dihalogen-2-hydroxyphenyl)-5,6,7,8,9,10-hexahydrobenzo[b][1,6]naphthyridines were synthesized with excellent yields (90–99%). The investigation of the transformation using 1H-NMR monitoring made it possible to confirm the ANRORC mechanism. The structures of synthesized compounds were confirmed by 2D-NMR spectroscopy

Quaternary Ammonium Compounds (QACs) and Ionic Liquids (ILs) as Biocides: From Simple Antiseptics to Tunable Antimicrobials

Quaternary ammonium compounds (QACs) belong to a well-known class of cationic biocides with a broad spectrum of antimicrobial activity. They are used as essential components in surfactants, personal hygiene products, cosmetics, softeners, dyes, biological dyes, antiseptics, and disinfectants. Simple but varied in their structure, QACs are divided into several subclasses: Mono-, bis-, multi-, and poly-derivatives. Since the beginning of the 20th century, a significant amount of work has been dedicated to the advancement of this class of biocides. Thus, more than 700 articles on QACs were published only in 2020, according to the modern literature. The structural variability and diverse biological activity of ionic liquids (ILs) make them highly prospective for developing new types of biocides. QACs and ILs bear a common key element in the molecular structure–quaternary positively charged nitrogen atoms within a cyclic or acyclic structural framework. The state-of-the-art research level and paramount demand in modern society recall the rapid development of a new generation of tunable antimicrobials. This review focuses on the main QACs exhibiting antimicrobial and antifungal properties, commercial products based on QACs, and the latest discoveries in QACs and ILs connected with biocide development