N-Heterotriangulene chromophores with 4-pyridyl anchors for dye-sensitized solar cells

Abstract

A series of N-heterotriangulenes decorated with 4-pyridyl anchors were synthesized and their performance in n-type TiO2- and ZnO-based dye-sensitized solar cells investigated.

Stability of Odd‐ Versus Even‐Electron Gas‐Phase (Quasi)Molecular Ions Derived from Pyridine‐Substituted N‐Heterotriangulenes

“…The four N‐heterotriangulenes under study (Figure ) are referred to as NTG and NTGPy n , with n =1–3, depending on the number of attached 4‐pyridyl groups . Figure shows their respective ESI mass spectra when sprayed from MeCN solution.…”

“…Particular applications include their use as organic dyes, for bio‐imaging and assays, catalysis and physisorption of carbon dioxide . The title compounds were recently used successfully in n‐type TiO 2 ‐ and ZnO‐based dye‐sensitised solar cells employing the 4‐pyridyl moiety as an anchor …”

“…Our previous research confirms the validity of these parameters . In the present case, the half‐wave oxidation potentials of all four compounds are low, ranging from 0.36 V for NTG to 0.56 V for NTGPy 3 as measured by cyclic voltammetry (all potentials are referenced against the ferrocene/ferrocenium (Fc/Fc + ) redox pair), and leading to the successful formation of their radical cations. However, for NTGPy 2 and NTGPy 3 , protonation prevails.…”

“…The four N‐heterotriangulenes (Figure ), which were synthesised according to the procedure published previously, were dissolved separately in acetonitrile with a concentration of 0.2 mg mL −1 . The stock solutions obtained were diluted with a mixture of dichloromethane CH 2 Cl 2 /MeCN=1:2 and CH 2 Cl 2 /MeOH=1:2 to give a concentration of 0.01 m m .…”

Bridged triarylboranes, ‐silanes, ‐amines, and ‐phosphines as minimalistic heteroatom‐containing polycyclic aromatic hydrocarbons: Progress and challenges

“…Compound 52 represents a notable exception in that it could be synthesized directly from the parent triarylamine scaffold 2 via Friedel‐Crafts‐type reaction with squaryl chloride without the need for preceding bromination. Other current examples of bridged triphenylamine sensitizers comprise 4‐pyridyl decorated compounds 53 to 55 that were specifically designed to systematically study the anchoring capabilities of pyridyl substituents in n‐type TiO 2 ‐ and ZnO‐based DSSCs. In this series, bipyridyl decorated compound 54 exhibited the best performance with a PCE of 4.5%, which was ascribed to a favorable balance between efficient binding to the metal oxide surface and suppression of the self‐aggregation once immobilized onto the electrode surface.…”