A variety of arylamines are shown to undergo oxidative C-C bond formation using quinone-based chloranil/H+ reagent as the recyclable organic (metal-free) oxidant system to afford benzidines/naphthidines. Arylamines (3°/2°) designed with various substituents were employed to understand the steric as well as electronic preferences of oxidative dimerization, and a mechanism involving amine radical cation has been proposed. The tetraphenylbenzidine derivative obtained via oxidative C-C coupling has been further converted to blue-emissive hole-transporting material via a simple chemical transformation. This study highlights the preparation of novel HTMs in a simple, economic, and efficient manner. © 2017 American Chemical Society.

Parthasarathy Venkatakrishnan

Department Of Chemistry

Sudhakar Maddala

Sudesh Mallick

Chemical bonds

ARYL AMINES

C-C bond formation

C-C coupling

Chemical transformations

HOLE-TRANSPORTING MATERIALS

Metal free

OXIDATIVE DIMERIZATION

Radical cations

Oxidants

alkyl group

Amine

aromatic amine

carbon

cation

CHLORANIL

oxidizing agent

quinone derivative

radical

TETRAPHENYLBENZIDINE DERIVATIVE

unclassified drug

Absorption spectroscopy

article

chemical bond

chemical structure

cross coupling reaction

dimerization

oxidation reduction potential

oxidative coupling

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Organic Chemistry

In this study, we synthesized three simple and inexpensive (34-120 USD/g) 3,3′-bicarbazole-based hole transporting materials (BC-HTMs; NP-BC, NBP-BC and PNP-BC) through a metal-free oxidative coupling, in excellent yields (≥95%). These bicarbazoles contain phenylene or biphenylene substituents on the carbazole N atom, with extended Ï€-conjugation achieved through phenylene units at the 6,6′-positions of the bicarbazole. When using NBP-BC as a dopant-free HTM in a p-i-n perovskite solar cell (PSC), we achieved a power conversion efficiency (PCEs) of 12.22 ± 0.54% under AM 1.5G conditions (100 mW cm-2); this PCE was comparable to that obtained when using PEDOT:PSS as the HTM (11.23 ± 1.02%). BC-HTMs showed the large grain size (μm) of perovskite than PEDOT:PSS-based, due to defect passivation on indium tin oxide (ITO) substrate and good hydrophobicity. Furthermore, we realized highly efficient and stable PSCs when using the p-i-n device structure ITO/NiOx/NP-BC/perovskite/PC61BM/BCP/Ag. The bifacial defect passivation effect of the interfacial layer improved the grain size of the perovskite layer and also enhanced the performance; the best performance of the NiOx/NP-BC device was characterized by a short-circuit current density (Jsc) of 22.38 mA cm-2, an open-circuit voltage (Voc) of 1.09 V, and a fill factor (FF) of 79.9%, corresponding to an overall PCE of almost 20%. This device structure has competitive potential because its performance is comparable to that of the record-high-efficiency PSCs. Under an Ar atmosphere, the PCE of the NiOx/NP-BC PSC device decayed by only 4.55% after 168 h; it retained 90.80% of its original PCE after 1000 h. A morphological study revealed that the films of the BC-HTMs were indeed smooth and hydrophobic and that the perovskite films spin-coated upon them were uniform and featured large grains (micrometer scale). Time-resolved photoluminescence (TRPL) spectra of the perovskite films suggested that the hole extraction capabilities of the NiOx/BC-HTMs were better than that of the bare NiOx. The superior film morphologies of the NiOx/BC-HTMs were responsible for the performances of their devices being comparable to those of bare NiOx-based PSCs. © 2019 American Chemical Society.

Chemistry of Materials

Forming a Metal-Free Oxidatively Coupled Agent, Bicarbazole, as a Defect Passivation for HTM and an Interfacial Layer in a p-i-n Perovskite Solar Cell Exhibits Nearly 20% Efficiency

Oxidative C-C coupling of carbazoles possessing various substituents is demonstrated in the presence of organic (metal-free) recyclable oxidants, such as DDQ or CA/H + , for accessing bicarbazole regioisomers. Differently substituted carbazoles are examined to showcase regioselective discrimination (3,3′-versus 1,3′-bicarbazoles) and preferences based on sterics and electronics in oxidative coupling. Finally, a mechanism that involves the carbazole radical cation has been traced (evidenced) and proposed on the basis of the UV-vis-NIR absorption and EPR spectroscopy results. This study underlines the strategic chemical preparation of a series of bicarbazoles in an efficient manner. © 2018 American Chemical Society.

Oxidative Coupling of Carbazoles: A Substituent-Governed Regioselectivity Profile

Metal-Free Oxidative C-C Coupling of Arylamines Using a Quinone-Based Organic Oxidant

Antioxidants

Protective Effects of Dendropanax morbifera against Cisplatin-Induced Nephrotoxicity without Altering Chemotherapeutic Efficacy

PeerJ

Figure 8: The MIPS curves were plotted before injury and 0 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min after injury in the frequency of 50 MHz to 70 MHz.

Crystal Growth & Design

Molecular Engineering of Triphenylamine Based Aggregation Enhanced Emissive Fluorophore: Structure-Dependent Mechanochromism and Self-Reversible Fluorescence Switching

Organic & Biomolecular Chemistry

Pd-indenyl-diphosphine: an effective catalyst for the preparation of triarylamines

Journal	Data powered by TypesetJournal of Organic Chemistry
Publisher	Data powered by TypesetAmerican Chemical Society
ISSN	00223263
Open Access	No