Two Dimensional Infrared Spectroscopy …
51
of the room temperature ionic liquid with controlled nanometer thicknesses have
been observed to be slower than the dynamics of the bulk liquid [93]. 2D IR spectroscopy demonstrated that the metal-polymer structure formed in paint films adopt
either a coordination chain or an oxo-type cluster and the presence of water governs
the relative concentration of these coordination structures [94]. The solvation structure and dynamics of lithium ions in carbonate electrolytes has revealed chemical
exchanges between carbonate solvent molecules in the first and outer solvation shells
[95]. Two-dimensional infrared (2D IR) spectroscopy used to study a thin film of
the Pb-I-SCN layered perovskite using near Brewster’s angle reflection pump−probe
geometry demonstrates that the lattice structure is dynamically disordered in contrast
to structurally isolated layer [96]. 2D IR spectroscopy in combination with ab-initio
molecular dynamics simulations revealed different rotational processes of the organic
cations within the methylammonium (MA) lead iodide [97]. The sensitivity of a silane
probe to the spectral diffusion on the nanometer length scale within the porous silica
nanoparticle with different pore size has shown slower solvent dynamics near the
surface-bound probe than that of the bulk solvent [98]. The process of gelation and
aging in silica sol-gel has been observed through monitoring the change in the peak
shape of a surface-bound Si–H vibration [98].
Covalently bound silicon hydride has been used to measure the structural
dynamics of an oligomeric cross-linker and a cross-linked elastomer in the solvent
and solvent free condition. The observed structural dynamics of polymer in similar
timescale of solvent dynamics has indicated the contribution of structural motion
of the polymer to the dynamics in its state swollen with solvent [99]. 2D-IR spectroscopy has observed a condition of decreased charge carrier mobilities in poly(3hexylthiophene-2,5-diyl) (P3HT) films. The solvent vapor annealing causes increase
in hole mobility which also consistent with the loss of dynamics in the 2D IR
measurement that suggest the damping of ring torsion vibrational modes in the
100–200 cm
−1 regime [100]. 2D-IR measurement on the structural dynamics of
polyaniline in its semiconducting undoped and conducting doped forms has revealed
ultrafast dynamics only for the undoped semiconducting films [101]. To investigate
solvent dynamics adjacent to the surface of a confined volume, a pore within a porous
silica gel has been measured using a 2D-IR spectroscopy [102]. Water dynamics in
the hydrated Nafion-212 with sodium counter ion has demonstrated that water in
the Nafion core acts essentially like bulk water, and the interfacial water dynamics
are the result of interactions with an interface of sulfonate anions [103]. Ultrafast
infrared spectroscopy has been used to measure the vibrational dynamics of Pt–H on
a nano-structured platinum surface. The vibrational lifetime and anharmonic shift is
larger for the Pt–H than that of the Pt–CO which indicates the coupling of H and CO
with metal [104].
51
of the room temperature ionic liquid with controlled nanometer thicknesses have
been observed to be slower than the dynamics of the bulk liquid [93]. 2D IR spectroscopy demonstrated that the metal-polymer structure formed in paint films adopt
either a coordination chain or an oxo-type cluster and the presence of water governs
the relative concentration of these coordination structures [94]. The solvation structure and dynamics of lithium ions in carbonate electrolytes has revealed chemical
exchanges between carbonate solvent molecules in the first and outer solvation shells
[95]. Two-dimensional infrared (2D IR) spectroscopy used to study a thin film of
the Pb-I-SCN layered perovskite using near Brewster’s angle reflection pump−probe
geometry demonstrates that the lattice structure is dynamically disordered in contrast
to structurally isolated layer [96]. 2D IR spectroscopy in combination with ab-initio
molecular dynamics simulations revealed different rotational processes of the organic
cations within the methylammonium (MA) lead iodide [97]. The sensitivity of a silane
probe to the spectral diffusion on the nanometer length scale within the porous silica
nanoparticle with different pore size has shown slower solvent dynamics near the
surface-bound probe than that of the bulk solvent [98]. The process of gelation and
aging in silica sol-gel has been observed through monitoring the change in the peak
shape of a surface-bound Si–H vibration [98].
Covalently bound silicon hydride has been used to measure the structural
dynamics of an oligomeric cross-linker and a cross-linked elastomer in the solvent
and solvent free condition. The observed structural dynamics of polymer in similar
timescale of solvent dynamics has indicated the contribution of structural motion
of the polymer to the dynamics in its state swollen with solvent [99]. 2D-IR spectroscopy has observed a condition of decreased charge carrier mobilities in poly(3hexylthiophene-2,5-diyl) (P3HT) films. The solvent vapor annealing causes increase
in hole mobility which also consistent with the loss of dynamics in the 2D IR
measurement that suggest the damping of ring torsion vibrational modes in the
100–200 cm
−1 regime [100]. 2D-IR measurement on the structural dynamics of
polyaniline in its semiconducting undoped and conducting doped forms has revealed
ultrafast dynamics only for the undoped semiconducting films [101]. To investigate
solvent dynamics adjacent to the surface of a confined volume, a pore within a porous
silica gel has been measured using a 2D-IR spectroscopy [102]. Water dynamics in
the hydrated Nafion-212 with sodium counter ion has demonstrated that water in
the Nafion core acts essentially like bulk water, and the interfacial water dynamics
are the result of interactions with an interface of sulfonate anions [103]. Ultrafast
infrared spectroscopy has been used to measure the vibrational dynamics of Pt–H on
a nano-structured platinum surface. The vibrational lifetime and anharmonic shift is
larger for the Pt–H than that of the Pt–CO which indicates the coupling of H and CO
with metal [104].