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 cm-1 with a high spectral resolution of 0.0001cm-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 cm-1 is also reported.