Connecting the Dots: Building Spectroscopic Blocks

Published in Chemistry
       Connecting the Dots: Building Spectroscopic Blocks
Like

Share this post

Choose a social network to share with, or copy the URL to share elsewhere

This is a representation of how your post may appear on social media. The actual post will vary between social networks

The arrival of LASER has ushered a new revolution in the field of spectroscopy. Several nonlinear spectroscopic experiments based on multiple pulse irradiation have been designed and successfully implemented. Nevertheless, the interest of chemists lies predominantly in understanding chemical reactions in bulk and at interfaces. At Paderborn university, we had been working on to provide a thorough understanding of the ‘On-water catalysis’. As theoretical chemists, we were posed with the question if we could provide a simple computational spectroscopic design to study chemical reactions on the interfaces.

This task involved merging two independent models or in the layman’s terminology ‘connecting the dots’. We had recently established a simple linear relationship between the hydrogen bond strength and the stretching mode of water molecules (Ojha et al. 2018). These linear relations let us selectively pick water molecules with a specific stretching frequency or in other words, "pump" water molecules to a given vibrational level. They also let us design the pulse with the width of our choice corresponding to both the broadband and narrow pulse excitation. We used this model in combination with the surface-specific velocity based sum-frequency generation spectroscopy (SFG) method (Ohto et al. 2015) to develop an elegant pulse sequence. The pulse sequence can be summarized as IR-pump SFG-probe spectroscopy. This combination lets us take a leap from conventional time-averaged SFG to a paradigm of time-dependent SFG at no extra computational cost. Moreover, it also lets you circumvent the tedious response functions calculation which is needed to obtain time-resolved two-dimensional SFG. In a nutshell, our model of time-dependent SFG could be used to study the dynamics of generic surface-specific chemical processes.



On the one hand,  the water molecules orientated towards the surface which are not hydrogen bonded have a greater propensity to form a hydrogen bond. On the other hand, a hydrogen-bonded water molecule pointing towards bulk takes more time to break a hydrogen bond. We used our computational time-dependent SFG to quantitatively establish this conventional wisdom.  The computational implementation of time-dependent SFG opens the avenues for the development of new and more complex pulse sequences. As future work, we are looking forward to studying prototype reactions at the aqueous-organic interface using this method. While we have only connected two dots, a lot remains to be explored! Read the complete story at Communication Chemistry.



References:

1. Ojha et al.  Sci. Rep. 8, 16888 (2018)

 2. Ohto et al.  J. Chem. Phys. 143, 124702 (2015)

   

Please sign in or register for FREE

If you are a registered user on Research Communities by Springer Nature, please sign in

Follow the Topic

Chemistry
Physical Sciences > Chemistry

Related Collections

With collections, you can get published faster and increase your visibility.

Mass spectrometry method development

Mass spectrometry is a cornerstone technique across various scientific disciplines, enabling precise analysis of complex samples, characterization of atom clusters and molecules, and elucidation of reaction mechanisms. This cross-journal Collection brings together advances in method development for mass spectrometry, including but not limited to advances in sample preparation, instrumentation, automation and integration, computational data analysis and prediction.

Publishing Model: Open Access

Deadline: Apr 30, 2025

Self-Assembled Soft Matter

In this cross-journal Collection, across Nature Communications, Communications Chemistry, Communications Materials and Scientific Reports, we focus on different forms of self-assembled soft matter, from fundamental studies to applied systems. This includes, for example, coacervation and liquid-liquid phase separation, chiral systems and polymer assemblies.

Publishing Model: Open Access

Deadline: Apr 30, 2025