4,6-Bis((E)-2-(4′-N,N-diphenylamino-[1,1′-biphenyl]-4-yl)vinyl)-2-phenylpyrimidine

Lacina Diarra,Françoise Robin-Le Guen,Sylvain Achelle

doi:10.3390/m1278

Abstract

In this contribution, we designed a 4,6-distyrylpyrimidine chromophore with diphenylamino electron-donating groups and biphenylenevinylene extended π-conjugated linkers. This compound has been synthesized in two steps from 4,6-dimethyl-2-phenylpyrimidine by a double Knoevenagel reaction with 4-bromobenzaldehyde followed by a double Suzuki–Miyaura cross coupling reaction with 4-(N,N-diphenylamino)phenylboronic acid. This compound exhibits intense emission in moderately polar solvents as well as in solid state. This compound is characterized by an intense emission solvatochromism with emission ranging from blue in non polar n-heptane to orange in dichloromethane. This chromophore is also sensible to the presence of acid with a bathochromic shift of the charge transfer absorption band and emission quenching.

Highlights

During the past two decades, there has been an important interest in the design of pyrimidine-based emissive materials [1,2]
Pyrimidine chromophores have been extensively used as fluorescent sensors for acidity [4], polarity [5], metal cations [6] or nitro-aromatic explosives [7]
Pyrimidine derivatives have been used with success as emitters for organic light emitting diodes (OLEDs), in particular for third generation OLEDs based on thermally activated delayed fluorescence [8,9]

Summary

Introduction

During the past two decades, there has been an important interest in the design of pyrimidine-based emissive materials [1,2]. The pyrimidine heterocycle is a six-membered aromatic ring with two nitrogen atoms in positions 1 and 3. 4,6-distyrylpyrimidine derivatives are well-known for their two-photon absorption properties and numerous structures have been developed for bio-imaging in particular [11]. In this short note we describe a new 4,6-distyrylpyrimidine emissive material combining diphenylamino strong electrondonating groups that is known to induce strong emission [12] and biphenylenevinylene extended π-conjugated linkers that should induce strong emission solvatochromism [13]. The presence of a phenyl ring in position 2 of the pyrimidine core may influence the photophysical and protonation properties of the chromophores

Synthesis

Photophysical

Materials and Methods

Methods