Search results for "Nato"

Tetrasubstituted Thieno[3,2- b]thiophenes as Hole-Transporting Materials for Perovskite Solar Cells

2019

Three hole-transporting materials (HTMs) were prepared following a straightforward synthetic route by cross-linking arylamine-based ligands with a simple thieno[3,2-b]thiophene (TbT) core. The novel HTMs were fully characterized with standard techniques to gain insight into their optical and electrochemical properties and were incorporated in solution-processed mesoporous (FAPbI3)0.85(MAPbBr3)0.15 perovskite-based solar cells. The similar molecular structure of the synthesized HTMs was leveraged to investigate the role that the bridging units between the conjugated TbT core and the peripheral arylamine units plays on their properties and thereby on the photovoltaic response. A remarkable po…

4,5-Disubstituted N -Methylimidazoles as Versatile Building Blocks for Defined Side-Chain Introduction

2017

Regioselective Metal- and Reagent-Free Arylation of Benzothiophenes by Dehydrogenative Electrosynthesis.

2018

A novel strategy for the synthesis of biaryls consisting of a benzothiophene and a phenol moiety is reported. These heterobiaryls are of utmost interest for pharmaceutical, biological, and high-performance optoelectronic applications. The metal- and reagent-free, electrosynthetic, and highly efficient method enables the generation of 2- and 3-(hydroxyphenyl)benzo[b]thiophenes in a regioselective fashion. The described one-step synthesis is easy to conduct, scalable, and inherently safe. The products are afforded in high yields of up to 88 % and with exquisite selectivity. The reaction also features a broad scope and tolerates a large variety of functional groups.

Systematic Investigation of Resorcin[4]arene-Based Cavitands as Affinity Materials on Quartz Crystal Microbalances.

2017

Resorcin[4]arene cavitands are well-known supramolecular hosts, and their outstanding guest-binding abilities in solution have been studied in detail in recent decades. In a systematic approach, different resorcin[4]arene cavitands and container molecules are characterized as affinity materials for gravimetric sensing using high-fundamental-frequency quartz crystal microbalances. Analysis of their affinity toward a series of various analytes reveals a remarkable dependence of both selectivity and sensitivity on the shape, accessibility, and size of the cavity, along with their supramolecular interactions with the host molecules.

Two-Photon Absorption Properties and Structures of BODIPY and Its Dyad, Triad and Tetrad.

2018

A series consisting of a dyad, a triad and a tetrad containing either two, three and four BODIPY units, respectively, has been synthesized and fully characterized and compared to two mono-BODIPY analogs (used as references). The one- and two-photon photophysical properties have been measured and the X-ray structures of four of the BODIPY derivatives have been determined. In the 700-900 nm range, the two-photon absorption (TPA) cross sections range from 30 GM to 160 GM for these compounds.

A Decade of Electrochemical Dehydrogenative C,C-Coupling of Aryls.

2019

The importance of sustainable and green synthetic protocols for the synthesis of fine chemicals has rapidly increased during the last decades in an effort to reduce the use of fossil fuels and other finite resources. The replacement of common reagents by electricity provides a cost- and atom-efficient, environmentally friendly, and inherently safe access to novel synthetic routes. The selective formation of carbon-carbon bonds between two distinct substrates is a crucial tool in organic chemistry. This fundamental transformation enables access to a broad variety of complex molecular architectures. In particular, the aryl-aryl bond formation has high significance for the preparation of organ…

Vinyl sulfone building blocks in covalently reversible reactions with thiols

2015

In the present study we use quantum-chemical calculations to investigate how the reactivity of vinyl sulfone-based compounds can be modified from an irreversible to a reversible reaction with thiols. Based on the predictions from theory, an array of nine different vinyl sulfones with systematically varying substitution pattern was synthesized and their crystal structures were determined. Subsequent Hirshfeld surface analyses employing the principle of electrostatic complementarity aid the understanding of the crystal packing of the synthesized compounds. Reactivity studies against the nucleophile 2-phenylethanethiol mirror the properties predicted by the quantum-chemical computations in sol…

Stepwise Construction of Heterobimetallic Cages by an Extended Molecular Library Approach.

2017

Two novel heterobimetallic complexes, a trigonal-bipyramidal and a cubic one, have been synthesized and characterized using the same C3-symmetric metalloligand, prepared by a simple subcomponent self-assembly strategy. Adopting the molecular library approach, we chose a mononuclear, preorganized iron(II) complex as the metalloligand capable of self-assembly into a trigonal-bipyramidal or a cubic aggregate upon coordination to cis-protected C2-symmetric palladium(II) or unprotected tetravalent palladium(II) ions, respectively. The trigonal-bipyramidal complex was characterized by NMR and UV–vis spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and single-crystal X-ray diffrac…

Supramolecular Architectures Based on Phosphonic Acid Diesters

2014

The interest of phosphonic acid dialkyl esters for generation of metal-organic materials is discussed using derivatives of porphyrin and 1,10-phenanthroline series as representative examples.

Insights into the Mechanism of Anodic N–N Bond Formation by Dehydrogenative Coupling

2017

The electrochemical synthesis of pyrazolidine-3,5-diones and benzoxazoles by N-N bond formation and C,O linkage, respectively, represents an easy access to medicinally relevant structures. Electrochemistry as a key technology ensures a safe and sustainable approach. We gained insights in the mechanism of these reactions by combining cyclovoltammetric and synthetic studies. The electron-transfer behavior of anilides and dianilides was studied and led to the following conclusion: The N-N bond formation involves a diradical as intermediate, whereas the benzoxazole formation is based on a cationic mechanism. Besides these studies, we developed a synthetic route to mixed dianilides as starting m…