A High Contrast Tri-state Fluorescent Switch: Properties and Applications.
A high contrast tri-state fluorescent switch (FSPTPE) with both emission color change and on/off switching is achieved in a single molecular system by fusing the aggregation-induced emissive tetraphenylethene (TPE) with a molecular switch of spiropyran (SP). In contrast to most of the reported solid-state fluorescent switches, FSPTPE only exists in the amorphous phase in the ring-closed form owing to its highly asymmetric molecular geometry and weak intermolecular interactions, which leads to its grinding-inert stable cyan emission in the solid state. Such an amorphous phase facilitates the fast response of FSPTPE to acidic gases and induces the structural transition from the ring-closed form to ring-open form, accompanied with the "Off" state of the fluorescence. The structural transition leads to a planar molecular conformation and high dipole moment, which further results in strong intermolecular interactions and good crystallinity, so when the acid is added together with a solvent, both the ring-opening reaction and re-crystallization can be triggered to result in an orange emissive state. The reversible control between any two of the three states (cyan/orange/dark) can be achieved with acid/base or mechanical force/solvent treatment. Because of the stable initial state and high color contrast (Δλ=120 nm for cyan/orange switch, dark state ΦF<0.01 %), the fluorescent switch is very promising for applications such as displays, chemical or mechanical sensing, and anti-counterfeiting.
College of Instrumentation and Electrical Engineering, Jilin University, Changchun, 130061, P. R. China.|College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Xing
X
Su
College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Yi
Y
Wang
College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Xiaofeng
X
Fang
College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Yu-Mo
YM
Zhang
College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Ting
T
Zhang
College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Minjie
M
Li
College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Yifei
Y
Liu
College of Instrumentation and Electrical Engineering, Jilin University, Changchun, 130061, P. R. China.
Tingting
T
Lin
College of Chemistry, Jilin University, 2699 Qianjin street, Changchun, 130012, P. R. China.
Sean Xiao-An
SX
Zhang
aggregation-induced emission; fluorescent molecular switch; mechanochromic behavior; spiropyran; tetraphenylethene