signals drastically depend on the DMF/MeOH ratio. Moreover, a comparison with
2D IR spectra obtained in the pure solvents, as well as spectral diffusion dynamics
thereof indicated a complex solvation environment in the mixture, which cannot be
modeled by weighted sums of the pure solvent spectra.
The achieved experimental demonstration of the combination of 2D IR
spectroscopy with microfluidic conditions is an important step forward in the
direction of broadening the applicability of the method as an analytical tool. Starting
from this point, a series of additional investigations can be envisioned. As one most
obvious point, microfluidics open a versatile route to new variants of transient 2D
IR spectroscopy by the application of rapid mixing experiments [289–291]. Such
methods are extremely valuable in chemical biology regarding studies of ligandbinding [292] or protein folding [293, 294]. The experiments allow a microsecond
temporal resolution of reaction kinetics and minimal sample volumes, which are
important for ‘‘Lab on a chip’’ applications [295, 296]. Importantly, the achievable
temporal resolution in rapid mixing experiments depends on the spot size of the
laser beam thus potentially allowing an interesting combination of 2D IR
microscopy and high time-resolution rapid mixing laser spectroscopy in future
studies. Other future implementations of 2D IR and microfluidics may involve
attacking intermolecular interactions and ultrafast dynamics of reaction intermediates as problems from a chemical engineering point of view [297–299]. Finally,
microfluidics is also a powerful method in combinatorial chemistry [289, 300]. As
such, 2D IR might be applicable for the identification of new drugs, as well as the
clarification of reaction intermediates and altered yields between small and largescale chemical synthesis.
The fact that a 100 kHz system has been used for the described studies is not
solely a side remark. In particular, such conditions allow for very high statistics and
thus a comparatively high signal-to-noise ratio. Such laser systems therefore
increase the sensitivity of the method and allow high throughput applications with
acquisition times for single spectra as low as 5 s [288]. These considerations are
particularly important for establishing 2D IR spectroscopy as an analytical tool in
chemistry, biology and chemical engineering. This is similarly important for
advanced methods such as 2D IR microscopy [301–303], which in combination with
microfluidics may be even more powerful than the currently available methods.
Finally, all envisioned applications of 2D IR spectroscopy as an analytical
method are likely to involve automated data acquisition [91, 304]. This is
particularly important since that approach reduces the work force needed to perform
laboratory experiments. As an important development in this direction, Rubtsov
et al. have recently devised a versatile and automated multi-color 2D IR
spectrometer that can operate between 800–4000 cm
-1 and thus address any
diagonal and cross peak region needed for chemical analytics [305]. Such
developments therefore represent significant technological steps forward to broaden
the applicability of 2D IR spectroscopy.
Top Curr Chem (Z) (2017) 375:86
123
181
Reprinted from the journal
2D IR spectra obtained in the pure solvents, as well as spectral diffusion dynamics
thereof indicated a complex solvation environment in the mixture, which cannot be
modeled by weighted sums of the pure solvent spectra.
The achieved experimental demonstration of the combination of 2D IR
spectroscopy with microfluidic conditions is an important step forward in the
direction of broadening the applicability of the method as an analytical tool. Starting
from this point, a series of additional investigations can be envisioned. As one most
obvious point, microfluidics open a versatile route to new variants of transient 2D
IR spectroscopy by the application of rapid mixing experiments [289–291]. Such
methods are extremely valuable in chemical biology regarding studies of ligandbinding [292] or protein folding [293, 294]. The experiments allow a microsecond
temporal resolution of reaction kinetics and minimal sample volumes, which are
important for ‘‘Lab on a chip’’ applications [295, 296]. Importantly, the achievable
temporal resolution in rapid mixing experiments depends on the spot size of the
laser beam thus potentially allowing an interesting combination of 2D IR
microscopy and high time-resolution rapid mixing laser spectroscopy in future
studies. Other future implementations of 2D IR and microfluidics may involve
attacking intermolecular interactions and ultrafast dynamics of reaction intermediates as problems from a chemical engineering point of view [297–299]. Finally,
microfluidics is also a powerful method in combinatorial chemistry [289, 300]. As
such, 2D IR might be applicable for the identification of new drugs, as well as the
clarification of reaction intermediates and altered yields between small and largescale chemical synthesis.
The fact that a 100 kHz system has been used for the described studies is not
solely a side remark. In particular, such conditions allow for very high statistics and
thus a comparatively high signal-to-noise ratio. Such laser systems therefore
increase the sensitivity of the method and allow high throughput applications with
acquisition times for single spectra as low as 5 s [288]. These considerations are
particularly important for establishing 2D IR spectroscopy as an analytical tool in
chemistry, biology and chemical engineering. This is similarly important for
advanced methods such as 2D IR microscopy [301–303], which in combination with
microfluidics may be even more powerful than the currently available methods.
Finally, all envisioned applications of 2D IR spectroscopy as an analytical
method are likely to involve automated data acquisition [91, 304]. This is
particularly important since that approach reduces the work force needed to perform
laboratory experiments. As an important development in this direction, Rubtsov
et al. have recently devised a versatile and automated multi-color 2D IR
spectrometer that can operate between 800–4000 cm
-1 and thus address any
diagonal and cross peak region needed for chemical analytics [305]. Such
developments therefore represent significant technological steps forward to broaden
the applicability of 2D IR spectroscopy.
Top Curr Chem (Z) (2017) 375:86
123
181
Reprinted from the journal