Co‐assembly of Polyoxometalates and Zwitterionic Amphiphiles into Supramolecular Hydrogels: From Crystalline Fibrillar to Amorphous Micellar Networks

Abstract

Gelation mechanism is of utmost importance to the rational design of supramolecular hydrogelators.A lthough both kinetic and thermodynamic controlled self-assembly processes have been widely studied in hydrogels,the formation relationship between crystalline and amorphous gel networks still remains ambiguous.H erein, ag elation transformation from ak inetic to at hermodynamic process was achieved by balancing the rigidity and flexibility of the inorganic-organic co-assemblies.B yu sing polyoxometalates and zwitterionic amphiphiles,t he transition morphologies between crystalline and amorphous hydrogel networks were evidenced for the first time,a so rdered wormlike micelles.G iven the versatile applications of hydrogels in biological systems and materials science,these findings may highlight the potential of inorganicorganic binary supramolecular hydrogelators and fill in the blank between kinetic and thermodynamic controlled gelation processes.

Five concomitant polymorphs of a green fluorescent protein chromophore (GFPc) analogue: understanding variations in photoluminescence with π-stacking interactions

“…The chromophore of green fluorescent protein (GFPc) has attracted exceptional attention in the literature due to its remarkable photophysical and photochemical properties (Wu & Burgess, 2008;Deng & Zhu, 2017). Investigation of the bioluminescence principles of GFP has advanced the development of fluorescent materials and also yielded another approach towards unconventional fluorescent materials.…”

“…However, in the excited state, the internal E/Z isomerization of GFPc (Fig. S1 in the supporting information) makes it weakly emissive in solution (Wu & Burgess, 2008;Puthuvakkal & Manoj, 2019). Naumov et al correlated the photomechanical properties, dimerization and dimorphic modifications of various GFPc crystals with hydrogen bonding and -stacking interactions (Naumov et al, 2010).…”

Crystal structure and spectral studies of green fluorescent protein (GFP) chromophore analogue ethyl 2-[(4Z)-(6-hydroxy naphthalen-2-yl) methylene)-2-methyl-5-oxo-4,5-di hydro-1H-imidazol-1-yl] acetate

“…Baldridge et al investigated a reversible locking of BI moiety by pyridyl substitution, which produces selective 'turn on' fluorescence in the presence of Zn 2+ or Cd 2+ ions [16]. Wu and Burgess developed another approach by using a Lewis acid (BF2 group), which connect the benzylidine and imidazolinone ring to restrain the twisting, resulted a strong fluorescence in solutions [17]. Chen et al synthesized various ortho-hydroxylated GFP derivatives, which gave high emission in the solid state through intramolecular excited-state proton transfer (ESPT) pathways [18].…”

Emission enhancement of GFP chromophore in aggregated state via combination of self-restricted effect and supramolecular host–guest complexation

“…An effective strategy is to develop conformational locked chromophores via chemically locking strategy, which greatly suppresses the chromophores' free torsional rotations and results in highly luminescent chromophores. 33,34 Recently, our research group has constructed a family of unlocked self-restricted GFP chromophore analogues with dramatic emission enhancement in uid solutions. 35 Considering the non-emissive and ACQ nature of HBI, it is a great challenge to enhance its emission response in aggregated state in solutions.…”