Formation of Hydroxylamine in Low-Temperature Interstellar Model Ices

Abstract

We irradiated binary ice mixtures of ammonia (NH) and oxygen (O) ices at astrophysically relevant temperatures of 5.5 K with energetic electrons to mimic the energy transfer process that occurs in the track of galactic cosmic rays. By monitoring the newly formed molecules online and in situ utilizing Fourier transform infrared spectroscopy complemented by temperature-programmed desorption studies with single-photon photoionization reflectron time-of-flight mass spectrometry, the synthesis of hydroxylamine (NHOH), water (HO), hydrogen peroxide (HO), nitrosyl hydride (HNO), and a series of nitrogen oxides (NO, NO, NO, NO, NO) was evident. The synthetic pathway of the newly formed species, along with their rate constants, is discussed exploiting the kinetic fitting of the coupled differential equations representing the decomposition steps in the irradiated ice mixtures. Our studies suggest the hydroxylamine is likely formed through an insertion mechanism of suprathermal oxygen into the nitrogen-hydrogen bond of ammonia at such low temperatures. An isotope-labeled experiment examining the electron-irradiated D3-ammonia-oxygen (ND-O) ices was also conducted, which confirmed our findings. This study provides clear, concise evidence of the formation of hydroxylamine by irradiation of interstellar analogue ices and can help explain the question how potential precursors to complex biorelevant molecules may form in the interstellar medium.

A novel and stable hydroxylamine salt generated from betaine hydrochloride and its application in the synthesis of cyclohexanone oxime

“…Apparently, the characteristic peaks of primary ammonium (minor peak at approximately 2000 cm −1 ) were observed in the spectra of NH 2 OH•HCl and BHA, showing the existence of the effect of NH 2 OH and HCl. 12,34 The broad band in the 3200-3400 cm −1 region was assigned to the ν(O H) and ν(N H) vibrations in the COOH and HNOH groups of BHA, respectively. 34 The FTIR spectrum of BHA also showed ν as (CH 3 ) and ν as (COO ) vibrations in the ca 3000 cm −1 region and 1618 cm −1 , of which the latter was taken from the red shift of that of BH.…”

“…12,34 The broad band in the 3200-3400 cm −1 region was assigned to the ν(O H) and ν(N H) vibrations in the COOH and HNOH groups of BHA, respectively. 34 The FTIR spectrum of BHA also showed ν as (CH 3 ) and ν as (COO ) vibrations in the ca 3000 cm −1 region and 1618 cm −1 , of which the latter was taken from the red shift of that of BH. The obvious shift of COO implied the proximity effect between NH 2 OH and COOH group of BH.…”

A Vacuum Ultraviolet Photoionization Study on the Formation of N-methyl Formamide (HCONHCH3) in Deep Space: A Potential Interstellar Molecule with a Peptide Bond

“…This ice growth was monitored online and in situ via an interference pattern of the HeNe laser (λ=632.8 nm; CVI Melles-Griot; 25-LHP-230) reflected from the silver wafer and the ice surface. The recorded fringes translate into an ice thickness via Equation (1), which defines the thickness (d) of an ice and the dependence on the number of interference fringes (m), the laser wavelength (λ), and the angle of incidence of the laser beam (θ = 4°): (Turner et al 2015;Förstel et al 2016bFörstel et al , 2016cTsegaw et al 2017…”

On the formation and the isomer specific detection of methylacetylene (CH3CCH), propene (CH3CHCH2), cyclopropane (c-C3H6), vinylacetylene (CH2CHCCH), and 1,3-butadiene (CH2CHCHCH2) from interstellar methane ice analogues

“…The FTIR was operated in absorption-reflection-absorption mode at a reflection angle of 451 to the substrate normal in the mid-IR region from 5000 to 500 cm À1 with a resolution of 4 cm À1 at 2 minute intervals, which allowed collection of 30 spectra during the one hour of irradiation with 5 keV electrons. [91][92][93][94] Following the irradiation phase the ice was held isothermal at 5 K for one hour. Next, the substrate was heated to 300 K through a controlled ramp rate of 0.5 K min À1 (temperature programmed desorption; TPD).…”