Influence of Structure on Lifetime of the Excited State of New Heptamethinecyanines Based on Benzo[cd]Indole

Abstract

It is shown that new benzo[cd]indole-based heptamethinecyanines (HMCs) have an ultrashort lifetime τ of the photoexcited state and a high intensity of light absorption in the generation range of practically important neodymium lasers. The electronic structure and types of electronic transitions in HMCs are analyzed by the DFT and TD-DFT methods. The influence of vibronic and intermolecular interactions on τ is considered. The advantages of HMCs for passive mode locking of lasers over known dyes with ultrashort τ are demonstrated. The advantages of HMCs to implement passive mode locking of lasers over known dyes with ultrashort τ are demonstrated.