Near-infrared clusteroluminescence in amine-capped polyesters

Near-infrared (NIR) luminophores has many advantages in practical applications, however, the fabrication of NIR clusteroluminogens (CLgens) from nonconjugated luminescent polymers is still a big challenge owing to uncontrollable structures and photophysical properties. Herein, the first example of amine-capped aliphatic polyesters with full-spectrum CL from blue to NIR region based on amine-ester complexes is reported. Experimental and theoretical calculation results prove that, in addition to the blue CL (~470 nm) generated by n−π* transitions of isolated ester groups, the new red-to-NIR CL (600~780 nm) originate from short-range and long-range amine-ester complexes based on through-space charge transfer (TSCT), respectively. Compared with small molecules, the unique and abundant microstructures of polymer chains directly generate long-range complexes and induces NIR CL. Meanwhile, the intensity ratios of these CL peaks are easily manipulated by molar contents and types of amines, chain structures of polyesters. This work not only constructs a novel platform to design high-efficiency, controllable, full-spectrum CLgens and breaks though the wavelength limitation of CLgens for the first time, but also enriches the relationship of polymer structures and CL properties.