Supervisor’s Foreword
Near a decade, research on solid-state luminescent molecular materials exhibiting
alterations of photo-physical properties by external stimuli, such as heat, vapor, and
mechanical stress, has attracted many interests because of its high potential not only
to generate new functional sensor or security materials but also to have fundamental
scientific insight on solid-state physical chemistry. Generally, solid-state luminescence has many differences to luminescence properties in solution phase. For
example, excited state of luminophore will experience large steric effect in solid
state comparing to those in solution, resulting in different luminescence pathways.
Furthermore, luminophores are densely packed in solid state, which can form
intermolecular interactions, such as p-p stacking, generating different electronic
environments comparing to those in solution phase. In other words, photoluminescent properties in solid state are strongly affected by intermolecular packing
mode and/or molecular conformation, as well known as “crystal structure.” Thus,
exploring a rational design to control the crystal structure of luminescent materials
correlating the external stimulation would highly contribute to develop novel
stimuli-responsive luminescent properties. For development of the
stimulus-responsive solid-state materials, generating multiple phases and interconversion between the phases via stimulations should be designed. In the case of
molecular crystals, molecular structure is highly correlated with physical properties
of the crystals, as well as molecular arrangement and electronic environment.
The Ph.D. thesis of Mingoo Jin explores several molecular designs of luminophore which can form luminescent crystals exhibiting mechanical, vapor, or thermal
stimuli-responsive properties. The main strategy is hybrid of luminescent properties
of gold(I) complex and structural factors of biaryl moiety or dumbbell-shaped
molecule which could afford high chance to control molecular arrangement and/or
conformation in solid state.
In general, luminescence properties of gold(I) complexes originate from ligands,
especially their geometry around the gold atom, or from the presence of metal–
metal interaction, so-called aurophilic interaction. According to these features, the
electronic environment of gold(I) complex can easily be influenced by internal or
external changes, molecular conformations, the dipole moment of neighboring
v
Near a decade, research on solid-state luminescent molecular materials exhibiting
alterations of photo-physical properties by external stimuli, such as heat, vapor, and
mechanical stress, has attracted many interests because of its high potential not only
to generate new functional sensor or security materials but also to have fundamental
scientific insight on solid-state physical chemistry. Generally, solid-state luminescence has many differences to luminescence properties in solution phase. For
example, excited state of luminophore will experience large steric effect in solid
state comparing to those in solution, resulting in different luminescence pathways.
Furthermore, luminophores are densely packed in solid state, which can form
intermolecular interactions, such as p-p stacking, generating different electronic
environments comparing to those in solution phase. In other words, photoluminescent properties in solid state are strongly affected by intermolecular packing
mode and/or molecular conformation, as well known as “crystal structure.” Thus,
exploring a rational design to control the crystal structure of luminescent materials
correlating the external stimulation would highly contribute to develop novel
stimuli-responsive luminescent properties. For development of the
stimulus-responsive solid-state materials, generating multiple phases and interconversion between the phases via stimulations should be designed. In the case of
molecular crystals, molecular structure is highly correlated with physical properties
of the crystals, as well as molecular arrangement and electronic environment.
The Ph.D. thesis of Mingoo Jin explores several molecular designs of luminophore which can form luminescent crystals exhibiting mechanical, vapor, or thermal
stimuli-responsive properties. The main strategy is hybrid of luminescent properties
of gold(I) complex and structural factors of biaryl moiety or dumbbell-shaped
molecule which could afford high chance to control molecular arrangement and/or
conformation in solid state.
In general, luminescence properties of gold(I) complexes originate from ligands,
especially their geometry around the gold atom, or from the presence of metal–
metal interaction, so-called aurophilic interaction. According to these features, the
electronic environment of gold(I) complex can easily be influenced by internal or
external changes, molecular conformations, the dipole moment of neighboring
v