systems, and alternative molecular arrangements, resulting that the luminescence
properties can be altered by such a change of external or internal environment of the
gold(I) complex.
Biaryl group possessing two aryl plans connected by C–C bonding can form
various geometries via rotatable aryl plan. Such a structure feature may enable to
realize structural variation of molecule in a crystalline phase. Furthermore, biaryl
structure can exhibit “axial chirality.” For instance, 2,2′-disubstituted binaphthyl
compounds can exhibit stable axial chirality as (R) and (S) conformations. And,
2-mono-substituted biphenyl compounds can adopt (M) or (P) conformations based
on their helical chirality. In solution phase, these conformers rapidly interconvert
between each other, but in the solid state, the conformers should be trapped in some
conformation by the intermolecular packed environment, resulting in molecular or
crystalline chirality. This chirality in the solid state should guide to design concept
for controlling molecular arrangement and/or conformations in solid phase.
Generally, molecular crystals are assembled into close packing arrangements
that minimize the amount of empty space; consequently, molecules are forced to
decrease their individual degrees of freedom in the crystals. On the other hand, it
has been revealed that dumbbell-shaped molecules designed for having gyroscope
properties could form many types of crystalline phase having both highly ordered
molecular packing mode and fast molecular rotation dynamics, known as amphidynamic crystal.
This Ph.D. thesis describes several succeed examples of external stimuliresponsive luminescent solid-state materials via hybrid luminescent gold(I) complex and structural engineering approach based on chirality and/or molecular
rotation in solid state. These results afford frontier concepts to understand and
engineer the photo-physical properties in molecular crystals and those external
stimuli-responsive properties.
Sapporo, Hokkaido, Japan
February 2020
Prof. Hajime Ito
vi
Supervisor’s Foreword
properties can be altered by such a change of external or internal environment of the
gold(I) complex.
Biaryl group possessing two aryl plans connected by C–C bonding can form
various geometries via rotatable aryl plan. Such a structure feature may enable to
realize structural variation of molecule in a crystalline phase. Furthermore, biaryl
structure can exhibit “axial chirality.” For instance, 2,2′-disubstituted binaphthyl
compounds can exhibit stable axial chirality as (R) and (S) conformations. And,
2-mono-substituted biphenyl compounds can adopt (M) or (P) conformations based
on their helical chirality. In solution phase, these conformers rapidly interconvert
between each other, but in the solid state, the conformers should be trapped in some
conformation by the intermolecular packed environment, resulting in molecular or
crystalline chirality. This chirality in the solid state should guide to design concept
for controlling molecular arrangement and/or conformations in solid phase.
Generally, molecular crystals are assembled into close packing arrangements
that minimize the amount of empty space; consequently, molecules are forced to
decrease their individual degrees of freedom in the crystals. On the other hand, it
has been revealed that dumbbell-shaped molecules designed for having gyroscope
properties could form many types of crystalline phase having both highly ordered
molecular packing mode and fast molecular rotation dynamics, known as amphidynamic crystal.
This Ph.D. thesis describes several succeed examples of external stimuliresponsive luminescent solid-state materials via hybrid luminescent gold(I) complex and structural engineering approach based on chirality and/or molecular
rotation in solid state. These results afford frontier concepts to understand and
engineer the photo-physical properties in molecular crystals and those external
stimuli-responsive properties.
Sapporo, Hokkaido, Japan
February 2020
Prof. Hajime Ito
vi
Supervisor’s Foreword