Chapter 5
Mechanical-Stimulation-Triggered
and Solvent-Vapor-Induced Reverse
Single-Crystal-to-Single-Crystal Phase
Transitions with Alterations
of the Luminescence Color
Herein, the first example of reversible change of the luminescence based on two
SCSC phase transitions via mechanical cutting and solvent-vapor adsorption is
described. Crystallization of a gold(I) complex that bears CF 3 and biaryl moieties
from CH 2 Cl 2 /MeOH afforded a green-emitting single crystal packed in a polar space
group (Pna2 1 ). The green-emitting single crystals included MeOH molecules. Upon
cutting the crystal under MeOH vapor at 22 °C, the green-emitting single crystal
spontaneously changed into a centrosymmetric orange-emitting single crystal (P ¯
1)
under concomitant release of MeOH. Remarkably, the initial green-emitting crystal
could be recovered from the orange-emitting crystal by a solvent-induced SCSC transition under saturated MeOH vapor. The combination of two different types of SCSC
phase transitions enables the reversible structural and photoluminescent alternations.
5.1 Introduction
Luminescent solids that undergo solid-state structural changes upon external stimuli
under subsequent modification of their emission properties constitute an attractive
research subject owing to their potential applications for highly functional devices
or sensors [1]. Reversible emission change is also an important property for the
development of further compound functionalities [1g, 2]. In rare cases, certain
luminescent crystalline compounds undergo single-crystal-to-single-crystal (SCSC)
phase transitions upon temperature changes, irradiation with light, or exposure to
small-molecule vapors [3]. Although SCSC transitions are generally difficult, they
can provide detailed information on the molecular level pertaining to changes of
the structure and/or the emission properties [1g, 3–5]. One intriguing example of
such structural transitions in molecular crystals are mechanical-stimulation-triggered
© Springer Nature Singapore Pte Ltd. 2020
M. Jin, Novel Luminescent Crystalline Materials of Gold(I) Complexes
with Stimuli-Responsive Properties, Springer Theses,
https://doi.org/10.1007/978-981-15-4063-9_5
127
Mechanical-Stimulation-Triggered
and Solvent-Vapor-Induced Reverse
Single-Crystal-to-Single-Crystal Phase
Transitions with Alterations
of the Luminescence Color
Herein, the first example of reversible change of the luminescence based on two
SCSC phase transitions via mechanical cutting and solvent-vapor adsorption is
described. Crystallization of a gold(I) complex that bears CF 3 and biaryl moieties
from CH 2 Cl 2 /MeOH afforded a green-emitting single crystal packed in a polar space
group (Pna2 1 ). The green-emitting single crystals included MeOH molecules. Upon
cutting the crystal under MeOH vapor at 22 °C, the green-emitting single crystal
spontaneously changed into a centrosymmetric orange-emitting single crystal (P ¯
1)
under concomitant release of MeOH. Remarkably, the initial green-emitting crystal
could be recovered from the orange-emitting crystal by a solvent-induced SCSC transition under saturated MeOH vapor. The combination of two different types of SCSC
phase transitions enables the reversible structural and photoluminescent alternations.
5.1 Introduction
Luminescent solids that undergo solid-state structural changes upon external stimuli
under subsequent modification of their emission properties constitute an attractive
research subject owing to their potential applications for highly functional devices
or sensors [1]. Reversible emission change is also an important property for the
development of further compound functionalities [1g, 2]. In rare cases, certain
luminescent crystalline compounds undergo single-crystal-to-single-crystal (SCSC)
phase transitions upon temperature changes, irradiation with light, or exposure to
small-molecule vapors [3]. Although SCSC transitions are generally difficult, they
can provide detailed information on the molecular level pertaining to changes of
the structure and/or the emission properties [1g, 3–5]. One intriguing example of
such structural transitions in molecular crystals are mechanical-stimulation-triggered
© Springer Nature Singapore Pte Ltd. 2020
M. Jin, Novel Luminescent Crystalline Materials of Gold(I) Complexes
with Stimuli-Responsive Properties, Springer Theses,
https://doi.org/10.1007/978-981-15-4063-9_5
127