Hyperbranched Polyborate: A Non‐conjugated Fluorescent Polymer with Unanticipated High Quantum Yield and Multicolor Emission

Abstract

Non-conjugated fluorescent polymers have attracted great attention due to their excellent biocompatibility and environmental friendliness. However, it remains a huge challenge to obtain a polymer with high fluorescence quantum yield (QY) and multicolor emission simultaneously. Herein, we reported three kinds of nonaromatic hyperbranched polyborates (P1-P3) with multicolor emission, surprisingly, P2 also exhibits an unanticipated high QY (54.1 %). The natural bond orbital (NBO) analysis and density functional theory (DFT) calculation results revealed that the synergistic effect of rigid BO 3 planar and flexible carbon chain, as well as the through-space dative bond in supramolecular aggregate, were the key factors contributing to the ultrahigh QY of P2. Moreover, the applications of P2 in Fe 3 + ions detection and cell imaging were also investigated. This work provides a new perspective for designing non-conjugated fluorescent polymers with both high QY and multicolor emission.

Barbier single-atom polymerization induced emission as a one-pot approach towards stimuli-responsive luminescent polymers

“…These results indicate that the nonconjugated luminescence of these Barbier SAP polymers is attributed to the throughspace conjugation effect between the N,N-dimethylaminotriphenylmethanol moieties and the intramolecular charge transfer caused by polymer chain entanglement, which is similar to previous reports on PIE and nonconjugated emission. 38,40,47,[50][51][52][53][54][55][56] Upon comparing the calculation results of the HOMO, the LUMO and the band gap of polymer with and without the N,N-dimethyl moiety, the polymer with the N, N-dimethyl moiety has the higher HOMO and LUMO and the narrower band gap at the same degree of polymerization, resulting in the red-shifted nonconjugated emission (Fig. S22-24 †), which will be discussed further.…”

High-Efficiency Long-Wavelength Fluorescent Hyperbranched Polysiloxanes: Synthesis, Emission Mechanism, Information Encryption, and Film Preparation

“…Unconventional fluorescent polymers are gaining increasing attention due to their good water solubility, excellent biocompatibility, facile preparation, and potential applications in cell imaging, drug delivery, biosensors, and data security. These polymers usually contain electron-rich atoms, such as oxygen (O), nitrogen (N), sulfur (S), phosphor (P), and halogen atoms (F and Cl) and functional groups containing π and lone pair (n) electrons, such as hydroxy (OH), amino (NH 2 ), carbonyl (CO), sulfhydryl (−SH), and disulfide bond (S–S). − Poly­(amino amide)­s, polyborate, polyacrylonitrile, poly­(vinylidene fluoride), poly­(amino ester)­s, polysiloxane, and polyester are the most investigated polymers.…”

“…These polymers usually contain electron-rich atoms, such as oxygen (O), nitrogen (N), sulfur (S), phosphor (P), and halogen atoms (F and Cl) and functional groups containing π and lone pair (n) electrons, such as hydroxy (OH), amino (NH 2 ), carbonyl (C�O), sulfhydryl (−SH), and disulfide bond (S−S). 1−3 Poly(amino amide)s, 4 polyborate, 5 polyacrylonitrile, 6 poly(vinylidene fluoride), 7 poly(amino ester)s, 8 polysiloxane, 9 and polyester 10 are the most investigated polymers.…”

Nonconventional Fluorescent Hyperbranched Polymer Dots as Skin Nanocarriers Constructed from an Olefinic Aliphatic AB2-Type Monomer

“…Nonconventional fluorescent hyperbranched polymers (HBPs) are highly branched macromolecules that produce strong fluorescence emissions in the absence of π-conjugated systems, the result of spatial conjugation appearing within globular molecule confinement. − The spatial conjugation systems within HBPs generate various energy band gaps from electron-rich atoms (N, O, P, and S) and the clustering of CO, CN, NH 2 , and OH functional groups. − Moreover, the inter- and intramolecular chains of HBPs cause intrinsic emissions to occur through hydrogen bonding, dipole–dipole interactions, the interactions of n−π* and π–π* systems, and oxygen–oxygen short contacts. − These types of nonconventional fluorescence arise from clustering-induced emission (CIE) and cross-link-enhanced emission (CEE). ,,− Conventional fluorescent polymers contain π-conjugated systems that undergo π–π stacking to induce fluorescence quenching. Nonconventional fluorescent polymers display the fluorescence of nonphotobleaching due to their nonconjugated structures producing spatial conjugation systems of aliphatic polar functional groups. ,, …”