Construction of wavelength-tunable DSE quinoline salt derivatives by regulating the hybridization form of the nitrogen atom and intramolecular torsion angle

Dual-state emission(DSE)molecules displayed conspicuous fluorescent performance both in solid and solution states.However,the construction of DSE molecules and the regulation of their emission wavelengths remains a great challenge.Based on the structure-function relationship of quinolinonitrile-type fluorophores,this work proposed a feasible strategy for modulating their fluorescent properties into DSE via limiting the torsion angle between the quinoline ring and C=C bond in the range of 4.7°to 30°.Based on this strategy,53 compounds were obtained which displayed tunable emission wavelengths from^(3)97 nm to 740 nm in solid-state and from 360 nm to 672 nm in solution.The feasibility of the strategy was supported by a series of theoretical calculations,optical characterizations,and crystal analysis,suggesting the compounds have great potential in imaging living cells and tissues with desired wavelengths.

One-step growth of the interconnected carbon nanotubes/graphene hybrids from cuttlebone-derived bi-functional catalyst for lithium-ion batteries

Carbon nanotubes/graphene hybrid materials with excellent physicochemical properties can be widely ap-plied in the fields of energy storage,electrocatalysis,sensing,etc.Reducing the self-stacking and achiev-ing covalent interaction between carbon nanotubes and graphene are important to ensure a stable hi-erarchical architecture and effective mass transfer.Herein,we propose a one-step strategy to synthesize 3D interconnected carbon nanotubes/graphene hybrids on the easy-to-remove biomass-derived substrate.The calcined natural cuttlebone as bi-functional catalyst precursor can simultaneously grow carbon nan-otubes and graphene by one-step chemical vapor deposition without the addition of extra metal catalysts,while the interconnected structure can act as the porous template for graphene growth.The simultane-ous growth process can obtain covalent bonding between carbon nanotubes and graphene,while the crystalline quality and interlayer space can be adjusted by different carbon sources and growth parame-ters(e.g.,temperature).The one-step grown carbon nanotubes/graphene hybrids with seamless interfaces and hierarchical interconnected 3D structure can effectively enhance the electron transfer as well as the electrolyte infiltration efficiency.When utilized as lithium-ion batteries(LIBs)anode,a high specific ca-pacity(544 mAh g^(-1) at 0.1 A g^(-1)),good rate capability(200 mAh g^(-1) at 6.4 A g^(-1) with an ultrashort charge time of 113 s),and excellent cyclic stability can be achieved.This simple and one-step carbon nanotubes/graphene hybrids fabrication strategy can be easily scale-up and applied in various fields.