Efficient electronic communication-driven photoinduced charge-separation in 2-ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded N,N-dimethylaniline-anthracene assemblies

Abstract

Four relatively rigid assemblies I–IV have been designed to understand the factor governing the photoinduced electron transfer (PET) process in 2-ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded systems. Upon excitation, PET from the N,N-dimethylaniline group to the singlet anthracene takes place giving rise to a long-lived charge-separation state up to 56μs for assembly I and 13μs for assembly II. Moreover, the introduction of CH2 group(s) to assemblies I and II can significantly influence, or even switch off the intra-assembly PET process. Spectroscopic and electrochemical studies demonstrate efficient electronic communication responsible for the PET process in 2-ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded N,N-dimethylaniline-anthracene assemblies. The fast single-step electron-transfer and slow charge-recombination, as well as the high excitation energy conversion efficiency (78%), enable the assemblies to be advantageous for high light-energy conversion.