Details

Autor(en) / Beteiligte

• Liang, Qiong-Fang
• Zheng, Han-Wen
• Yang, Dong-Dong
• Zheng, Xiang-Jun

Titel

A triphenylamine derivative and its Cd() complex with high-contrast mechanochromic luminescence and vapochromism

Ist Teil von

• CrystEngComm, 2022-01, Vol.24 (3), p.543-551

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• An acetonitrile solvate of a Schiff base molecule (HL) with acetonitrile ( HL ·2CH 3 CN) and its Cd( ii ) complex (Cd(HL) 2 Cl 2 , 1 ) was designed and synthesized. The different conformation of HL in HL ·2CH 3 CN is adjusted by the hydrogen bonding O-H O between HL molecules, together with N-H N between HL molecules and acetonitrile molecules. Meanwhile, the conformation of HL in complex 1 is adjusted by coordination interactions between Zn ions and atoms O and N, together with hydrogen bonding N-H Cl. The presence of the triphenylamine group makes HL ·2CH 3 CN and complex 1 loosely packed. Upon grinding, HL ·2CH 3 CN and complex 1 both showed high-contrast mechanochromic luminescence (MCL) change from blue to green and cyan to yellow, respectively. These changes can be eliminated by fumigation with organic vapor. The results of powder X-ray diffraction (PXRD) show that their MCL is due to the phase transformation from a crystalline state to an amorphous state. In addition, HL ·2CH 3 CN and complex 1 also exhibited high-contrast acidochromism upon exposure to HCl and NH 3 vapor. X-ray photoelectron spectroscopy (XPS) and PXRD studies show that the protonation of the -NH- group together with phase transformation from a crystalline state to an amorphous state is attributed to the fluorescence switching. For HL ·2CH 3 CN, the protonation process was accompanied by the departure of acetonitrile molecules. The emission of HL was restored to the amorphous state rather than the original crystalline state emission after further exposure to NH 3 vapor, while 1 - HCl could revert to the original crystalline state emission. In addition, HL ·2CH 3 CN and complex 1 have been successfully used to produce writable and acid-responsive test papers. A triphenylamine derivative and its Cd( ii ) complex exhibited predominant mechanochromism and vapochromism with high-contrast color and emission changes.