Unusual strong fluorescence of a hyperbranched phosphate: discovery and explanations

Abstract

The unusual strong fluorescence of a hyperbranched molecule (3-hydroxyphenyl) phosphate (HHPP), which does not possess a rigid planar structure or obvious large p system, was discovered for the first time.The effects of the solvent polarity, pH value, concentration, and end group modification on the absorption and the fluorescence spectra of HHPP solutions were investigated. The terminal phenol groups and triphenyl phosphate (TPP) structures in HHPP were found to be responsible for two strong fluorescence peaks. The greatly enhanced fluorescence is explained by three factors. In particular, the special bridging effects of the phosphate groups in the hyperbranched molecules, which can form extended p electron systems, play an important role. It is suggested that the phosphate groups in the hyperbranched molecule could serve as effective bridging groups to connect various other fluorescence groups to form a new type of fluorescence molecule which does not have a rigid planar structure. In addition, the systematic colour changes with changing solvent polarity, mass concentration, and pH value make it a new potential probe in various applications.

Nonconventional macromolecular luminogens with aggregation‐induced emission characteristics

“…Conventional luminogens normally contain bulky aromatic or conjugated units with remarkable conjugation in individual molecules, which ensure them emissive . Besides these traditional luminogens, more recently, the observation of intrinsic photoluminescence (PL) from nonconventional luminogens in absence of any type of proverbial chromophores, some even free of any (hetero)cyclic aromatic building blocks has been reported . Among these emerging luminophors, nonconjugated polymers with chain flexibility and structure tunability have aroused great interests because of their significant fundamental importance and promising technical applications .…”

“…Among these emerging luminophors, nonconjugated polymers with chain flexibility and structure tunability have aroused great interests because of their significant fundamental importance and promising technical applications . Generally, these polymers involve electron‐rich heteroatoms, such as nitrogen (N), oxygen (O), sulfur (S), phosphorus (P), and/or unsaturated C = C and C≡N subgroups. Apart from the most intensively investigated archetypal poly(amidoamine)s (PAMAM), other macromolecular nonconventional luminogens, such as poly(amino ester)s (PAE), poly(ether amide)s (PEA), polyacrylonitrile (PAN), poly( N ‐vinylpyrrolidone) (PVP), polyethylenimines (PEI), polyureas (PU), sulfonated acetone–formaldehyde (SAF) condensates and derivatives, poly( N ‐hydroxysuccinimide methacrylate) (PNHSMA), polysiloxanes, and even supramolecular assemblies have been becoming increasingly eye‐catching owing to their unique intrinsic emissions.…”

A multifunctional silicon-containing hyperbranched epoxy: controlled synthesis, toughening bismaleimide and fluorescent properties

“…[37][38][39] From the traditional point of view, chromogenfree compounds rarely exhibit strong fluorescence; a few exceptions, however, have been covered recently, and they are those possessing dendritic or hyperbranched architecture, such as poly(amidoamine) (PAMAM), [40][41][42][43] polyureas (PURE), 44 hyperbranched phosphate (HBPP), 45 poly(ether amide)s (PEA), 46 poly-(propyleneimine) (PPI) 47 and poly(amino ester) (PAE). This is obviously different from the general organics bearing conventional fluorophores, which are usually emissive in their dilute solutions, but get weakly luminous or even non-luminescent in condensed solutions or solids.…”

Emission‐Color Control in Polymer Films by Memorized Fluorescence Solvatochromism in a New Class of Totally Organic Fluorescent Nanogel Particles

“…The quantum yield (QY) was calculated from the UV absorbance and the area of fluorescence spectra according to the following equation:…”