Nonplanar Organic Sensitizers Featuring a Tetraphenylethene Structure and Double Electron-Withdrawing Anchoring Groups

Two metal-free organic sensitizers containing two <i>N</i>,<i>N</i>-diethylaniline (DEA) moieties and a twisted 1,1,2,2-tetraphenylethene (TPE) structure, dye <b>SD</b> with one anchoring group and dye <b>DD</b> with two anchoring groups, were synthesized and applied in dye-sensitized solar cells (DSSCs). The introduction of a nonplanar TPE structure was used to form a series of propeller-like structures and reduce the tendency of dyes to randomly aggregate on TiO₂ surface, but without importing an aggregation-induced emission (AIE) property. The thermal stabilities, UV–vis absorption spectra, electrochemical properties, and photovoltaic parameters of DSSCs with these two dyes were systematically studied and compared with each other. The overall conversion efficiencies (η) of 4.56% for dye <b>SD</b> and 6.08% for dye <b>DD</b> were obtained under AM 1.5 G irradiation

Near-Infrared Luminescent PMMA-Supported Metallopolymers Based on Zn–Nd Schiff-Base Complexes

On the basis of self-assembly from the divinylphenyl-modified Salen-type Schiff-base ligands <b>H</b>_<b>2</b><b>L</b>^<b>1</b> (<i>N</i>,<i>N</i>′-bis­(5-(3′-vinylphenyl)-3-methoxy-salicylidene)­ethylene-1,2-diamine) or <b>H</b>_<b>2</b><b>L</b>^<b>2</b> (<i>N</i>,<i>N</i>′-bis­(5-(3′-vinylphenyl)-3-methoxy-salicylidene)­phenylene-1,2-diamine) with Zn­(OAc)₂·2H₂O and Ln­(NO₃)₃·6H₂O in the presence of pyridine (Py), two series of heterobinuclear Zn–Ln complexes [Zn­(L^<i>n</i>)­(Py)­Ln­(NO₃)₃] (<i>n</i> = 1, Ln = La, <b>1</b>; Ln = Nd, <b>2</b>; or Ln = Gd, <b>3</b> and <i>n</i> = 2, Ln = La, <b>4</b>; Ln = Nd, <b>5</b>; or Ln = Gd, <b>6</b>) are obtained, respectively. Further, through the physical doping and the controlled copolymerization with methyl methacrylate (MMA), two kinds of PMMA-supported hybrid materials, doped <b>PMMA/[Zn­(L</b>^{<b><i>n</i></b>}<b>)­(Py)­Ln­(NO</b>_<b>3</b><b>)</b>_<b>3</b><b>]</b> and Wolf Type II Zn²⁺–Ln³⁺-containing metallopolymers <b>Poly­(MMA-<i>co</i>-[Zn­(L</b>^{<b><i>n</i></b>}<b>)­(Py)­Ln­(NO</b>_<b>3</b><b>)</b>_<b>3</b><b>])</b>, are obtained, respectively. The result of their solid photophysical properties shows the strong and characteristic near-infrared (NIR) luminescent Nd³⁺-centered emissions for both <b>PMMA/[Zn­(L</b>^{<b><i>n</i></b>}<b>)­(Py)­Nd­(NO</b>_<b>3</b><b>)</b>_<b>3</b><b>]</b> and <b>Poly­(MMA-<i>co</i>-[Zn­(L</b>^{<b><i>n</i></b>}<b>)­(Py)­Nd­(NO</b>_<b>3</b><b>)</b>_<b>3</b><b>])</b>, where ethylene-linked hybrid materials endow relatively higher intrinsic quantum yields due to the sensitization from both ¹LC and ³LC of the chromorphore than those from only ¹LC in phenylene-linked hybrid materials, and the concentration self-quenching of Nd³⁺-based NIR luminescence could be effectively prevented for the copolymerized hybrid materials in comparison with the doped hybrid materials