A helium nanodroplets isolation spectrometer for high-resolution infrared spectroscopy of cold molecules and molecular aggregates

Abstract

A helium nanodroplets isolation spectrometer has been fabricated at IIT Kanpur (HeNDI-IITK) for investigating molecules, molecular clusters and chemical reactions at ultracold temperatures. To the best of our knowledge, this is the first HeNDI spectrometer developed in India and one of only a few worldwide. The spectrometer facilitates the formation and isolation of molecular clusters within superfluid helium droplets, which can then be investigated using mass spectrometry and mass-selective infrared spectroscopy. Currently, the spectrometer can perform mass spectrometry in the range of \(m/z=\)2–510 u and infrared spectroscopy in the range of 2500–4500 \(\text{cm}^{-1}\) with a high spectral resolution of \(0.0001\,{\text{cm}}^{-1}\), offering potential for extending both measurement ranges in future developments. In this article, we discuss the design and performance of the spectrometer. Mass-selective infrared spectrum of formic acid monomer in the frequency range of ∼3568.8–3572.7 \(\text{cm}^{-1}\) is also reported.

Graphical abstract