Preparation of non-conjugated polymers with longwavelength emission and high quantum yield (QY) is still ahuge challenge.Herein, we report the first example of linear non-conjugated polyester exhibiting yellow-green clusteroluminescence (CL) and ah igh QY of 38 %. We discovered that the polyester P3 with balanced flexibility and rigidity showed the longest CL wavelength and highest QY.S ystematically photophysical characterization unravel the key role of ester cluster in the CL and the cluster formation via the aggregate of ester units was visualized. Moreover,P 3w as demonstrated to be ah ighly selective,q uick-responsive (ca. 1.2 min) and sensitive detector (detection limit is 0.78 mM) for irons owing to the fast disassociation of clusters by irons.T his work not only gains further mechanistic insight into CL but also provides an ew strategy to design high-efficiency and longwavelength CL, meanwhile,enlightens the glorious application prospect of luminescent polyester.

Single-molecule white-light emission (SMWLE) has many advantages in practical applications; however, the fabrication of SMWLE from nonconjugated luminescent polymers, namely, clusteroluminogens (CLgens), is still a big challenge. Herein, the first example of linear nonconjugated polyesters with SMWLE is reported. Twenty-four kinds of nonconjugated aliphatic polyesters with tunable clusteroluminescence (CL) colors and efficiency were synthesized by the copolymerization of six epoxides and four anhydrides. Experimental and calculation results prove that, at the primary structure level, the balance of structural flexibility and rigidity via adjusting the side-chain length significantly enhances the efficiency of CL without wavelength change. However, altering the chemical structures of the monomer from succinic anhydride to trans-maleic anhydride (MA), cis-MA, and citraconic anhydride (CA), secondary structures of these polyesters change from helix to straight and folding sheet accompanied by gradually red-shifted CL from 460 to 570 nm due to the increase in through-space n–π* interactions, as demonstrated by the computational and experimental results. Then, pure SMWLE with CIE coordination (0.30, 0.32) based on overlapped short-wavelength and long-wavelength CL is achieved in CA-based polyesters. This work not only provides further insights into the emission mechanism of CL but also provides a new strategy to manipulate the properties of CL by regulating the hierarchical structures of CLgens.

Clusteroluminogens (CLgens), nonconjugated structures with visible luminescence at the clustering state, have recently received remarkable attention due to their great theoretical significance and practical values. In carbonyl‐based aliphatic polymers, (n, π*) transition of carbonyl groups and the through‐space interactions have been demonstrated to play an important role in their clusteroluminescence (CL) properties, but it is still a big challenge to manipulate their CL at the molecular level. In this work, six nonconjugated carbonyl‐based polymers with different heteroatoms and steric hindrances were synthesized, and their photophysical properties were systematically studied. These polymers all showed CL but with different emission efficiency and wavelength. Experimental and theoretical studies indicated that the CL properties could be manipulated by changing the electronic structures of carbonyl groups and the rigidity of polymer chains. This work not only gains further insights into the CL mechanism but also provides reliable strategies to design and manipulate non‐conjugated luminescent materials.

Carbonized polymer dots (CPDs) have received great research interest in recent years. However, the solid-state photoluminescence quenching of CPDs is a big challenge owing to resonance energy transfer or π–π*...

Nonconjugated luminescent polymers with white light emission are promising for a wide range of applications in display and lighting devices, but their preparation remains a big challenge. Herein, a white‐light‐emitting nonconjugated poly(hydroxyurethane) microsphere (PHUM) synthesized from the crosslinking reaction of trimethylolpropane tri(cyclic carbonate) ether and 1,6‐hexanediamine in chloroform is reported. The resultant PHUMs possess uniform sizes ranging from 12.6 to 21.5 µm. It is proposed that a high crosslinking degree and various hydrogen‐bonding strengths induce the formation of carbamate clusters with different sizes and broad distributions, which result in a broad emission spectrum. The cluster‐size distribution effect leads to multiple n–π* transitions from various carbamate clusters via through‐space conjugation of carbamates, realizing white light emission. In addition, the application of PHUMs as single phosphor combined with a 365 nm UV chip is also demonstrated, with which a white‐light‐emitting diode with a high color rendering index of up to 95 is obtained. This work confirms that crosslinking can induce multiple emissions, which provides a new clusteroluminescence and polymerization‐induced emission system for tunable luminescence emission.