Preparation and Photochemistry of Hydroxy Isocyanate

Area of Science:

• Astrochemistry
• Physical Chemistry
• Spectroscopy

Background:

• The chemical composition of the interstellar medium (ISM) is crucial for understanding star formation and the origins of life.
• Prebiotic chemistry explores the chemical reactions that could have led to the emergence of life on early Earth.
• Experimental identification of novel molecules provides foundational data for astrochemical models.

Purpose of the Study:

• To report the first spectroscopic identification of the hydroxy isocyanate (HONCO) molecule.
• To investigate the properties and reactivity of HONCO under laboratory conditions.
• To assess the potential relevance of HONCO in interstellar and prebiotic chemistry.

Main Methods:

• Gas-phase synthesis of HONCO via flash vacuum pyrolysis of phenyl N-hydroxycarbamate at 650 °C.
• Trapping of the synthesized HONCO in argon matrices at 3.5 K for stabilization.
• Characterization using matrix isolation infrared (IR) and UV/visible (UV/vis) spectroscopy.
• Supportive analysis through quantum chemical computations.

Main Results:

• Successful spectroscopic identification of the planar chain molecule HONCO.
• Detailed characterization of HONCO's vibrational and electronic transitions.
• Observation of HONCO decomposition into HON and HNO complexes with CO upon 313 nm UV irradiation.

Conclusions:

• The experimental synthesis and spectroscopic characterization of HONCO are achieved.
• HONCO is confirmed as a molecule of potential significance for interstellar and prebiotic chemical pathways.
• The photochemical reactivity of HONCO provides insights into its potential transformation in extraterrestrial environments.