48
D. Ghosh et al.
in [Co(CN) 6 ]
3− highly symmetric molecular species [44]. 2D IR spectroscopy has
been used to investigate the dynamics in a fragile glass forming liquid [45]. Metal
ion dependent vibrational relaxation in EDTA complex using carboxylate group as
a vibrational reporter has been reported [46]. Solvation dynamics in green solvents
like ionic liquids and DES have been interrogated [47–51].
Water dynamics has gathered considerable interest in the scientific community
because water in any confined environment behaves differently from bulk water.
To understand the dynamics of confined water, scientists have been studying the
hydrogen bond dynamics of water at the interface of reverse micelles and water for
a significant amount of time using 2D IR and pump probe spectroscopy [52, 53].
Dynamics of nanoscopic water in aerosol-OT reverse micelles have been studied
and the water dynamics have been separated into two different ensembles, namely
interfacial water and bulk like core water [52]. Water dynamics at the surfactant
interfacial boundary layer in large Aerosol-OT reverse micelles has been found to be
slower than in bulk water [53]. Studies on vibrational relaxation of water interacting
with ionic surface and molecular anionic H-bond dynamics in water provided interesting insights about water dynamics [54, 55]. Confined water dynamics was further
investigated inside the nanoporous silica materials were studied using SeCN
− as a
probe [56]. The water of hydration inside the crystals defines the physical property
of that mineral. Water dynamics inside minerals like gypsum and basanite have been
interrogated [57]. In addition, reorientational relaxation in DMSO/water, an industrially relevant solvent, has been found to depend on the concentration of water in the
binary solvent mixture [58]. Using isotope dilution of water, it has been found that
the OH frequency shifts arise from the changes in molecular electric fields acting on
the proton [58]. Study of interfacial energy dynamics of D 2 O in air/water interface
has shown a sub-picosecond transfer of energy between hydrogen bonded interfacial water molecules and the OD groups pointing out from the water surface [59].
To understand the role of water in biology, dynamics of water in enzyme active
sites have been investigated on NO bound ferric haem of the catalase enzyme from
Corynebacterium glutamicum in H 2 O and D 2 O [60]. Another example of studying
water dynamics in a biological context is the work on interfacial water dynamics in
the lipid membrane. It has been found that hydrophobic fragments affect the ultrafast rotational dynamics of water [61]. The impediment has been explained using
excluded volume effects in hydration [62]. 2D IR spectroscopy has been applied to
carbonyl and phosphate vibrations intrinsically located at the lipid–water interface to
examine the effects of DMSO on the H-bond dynamics [63]. In another work (Fig. 7),
the effects of membrane peptide concentration on the picosecond interfacial H-bond
dynamics reveal a non-monotonic dependence of water orientation and dynamics as
a function of transmembrane peptide:lipid ratio [64].
There are several examples of measuring structural, conformational, and solvation
dynamics of biological molecules using 2D IR. In small molecule-DNA interactions,
a therapeutic molecule, Hoechst33258, has been found to prefer to A-tract sequence
relative to a suboptimal alternating A-T sequence [65]. This technique has been
applied to screen 2016 2D IR spectra of 12 double-stranded DNA oligonucleotides
obtained in the presence and absence of Hoechst 33,258 to efficiently retrieve the
D. Ghosh et al.
in [Co(CN) 6 ]
3− highly symmetric molecular species [44]. 2D IR spectroscopy has
been used to investigate the dynamics in a fragile glass forming liquid [45]. Metal
ion dependent vibrational relaxation in EDTA complex using carboxylate group as
a vibrational reporter has been reported [46]. Solvation dynamics in green solvents
like ionic liquids and DES have been interrogated [47–51].
Water dynamics has gathered considerable interest in the scientific community
because water in any confined environment behaves differently from bulk water.
To understand the dynamics of confined water, scientists have been studying the
hydrogen bond dynamics of water at the interface of reverse micelles and water for
a significant amount of time using 2D IR and pump probe spectroscopy [52, 53].
Dynamics of nanoscopic water in aerosol-OT reverse micelles have been studied
and the water dynamics have been separated into two different ensembles, namely
interfacial water and bulk like core water [52]. Water dynamics at the surfactant
interfacial boundary layer in large Aerosol-OT reverse micelles has been found to be
slower than in bulk water [53]. Studies on vibrational relaxation of water interacting
with ionic surface and molecular anionic H-bond dynamics in water provided interesting insights about water dynamics [54, 55]. Confined water dynamics was further
investigated inside the nanoporous silica materials were studied using SeCN
− as a
probe [56]. The water of hydration inside the crystals defines the physical property
of that mineral. Water dynamics inside minerals like gypsum and basanite have been
interrogated [57]. In addition, reorientational relaxation in DMSO/water, an industrially relevant solvent, has been found to depend on the concentration of water in the
binary solvent mixture [58]. Using isotope dilution of water, it has been found that
the OH frequency shifts arise from the changes in molecular electric fields acting on
the proton [58]. Study of interfacial energy dynamics of D 2 O in air/water interface
has shown a sub-picosecond transfer of energy between hydrogen bonded interfacial water molecules and the OD groups pointing out from the water surface [59].
To understand the role of water in biology, dynamics of water in enzyme active
sites have been investigated on NO bound ferric haem of the catalase enzyme from
Corynebacterium glutamicum in H 2 O and D 2 O [60]. Another example of studying
water dynamics in a biological context is the work on interfacial water dynamics in
the lipid membrane. It has been found that hydrophobic fragments affect the ultrafast rotational dynamics of water [61]. The impediment has been explained using
excluded volume effects in hydration [62]. 2D IR spectroscopy has been applied to
carbonyl and phosphate vibrations intrinsically located at the lipid–water interface to
examine the effects of DMSO on the H-bond dynamics [63]. In another work (Fig. 7),
the effects of membrane peptide concentration on the picosecond interfacial H-bond
dynamics reveal a non-monotonic dependence of water orientation and dynamics as
a function of transmembrane peptide:lipid ratio [64].
There are several examples of measuring structural, conformational, and solvation
dynamics of biological molecules using 2D IR. In small molecule-DNA interactions,
a therapeutic molecule, Hoechst33258, has been found to prefer to A-tract sequence
relative to a suboptimal alternating A-T sequence [65]. This technique has been
applied to screen 2016 2D IR spectra of 12 double-stranded DNA oligonucleotides
obtained in the presence and absence of Hoechst 33,258 to efficiently retrieve the