J/ApJ/820/117 Energies & IR intensities of amide polymers (Forstel+, 2016)
On the formation of amide polymers via carbonyl-amino group linkages in
energetically processed ices of astrophysical relevance.
Forstel M., Maksyutenko P., Jones B.M., Sun B.J., Lee H.C., Chang A.H.H.,
Kaiser R.I.
<Astrophys. J., 820, 117 (2016)>
=2016ApJ...820..117F 2016ApJ...820..117F (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Interstellar medium
Keywords: astrobiology; astrochemistry; ISM: molecules;
methods: laboratory: molecular; molecular processes
Abstract:
We report on the formation of organic amide polymers via
carbonyl-amino group linkages in carbon monoxide and ammonia bearing
energetically processed ices of astrophysical relevance. The first
group comprises molecules with one carboxyl group and an increasing
number of amine moieties starting with formamide (45 u), urea (60 u),
and hydrazine carboxamide (75 u). The second group consists of species
with two carboxyl (58 u) and up to three amine groups (73 u, 88 u, and
103 u). The formation and polymerization of these linkages from simple
inorganic molecules via formamide und urea toward amide polymers is
discussed in an astrophysical and astrobiological context. Our results
show that long chain molecules, which are closely related to
polypeptides, easily form by energetically processing simple,
inorganic ices at very low temperatures and can be released into the
gas phase by sublimation of the ices in star-forming regions. Our
experimental results were obtained by employing reflectron
time-of-flight mass spectroscopy, coupled with soft, single photon
vacuum ultraviolet photoionization; they are complemented by
theoretical calculations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 98 74 Calculated minimum energy structures and energies of
the molecules under discussion
table4.dat 65 772 Geometries underlying the calculated energies
shown in table 3
table5.dat 67 1860 Calculated infrared band positions and intensities
of the molecules under discussion
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See also:
J/MNRAS/448/1704 : ExoMol line lists for formaldehyde H2CO (Al-Refaie+, 2015)
J/ApJ/783/77 : Transition line list for interstellar urea (Remijan+, 2014)
J/A+A/549/A128 : Singly deuterated isotopologues of formamide (Kutsenko+, 2013)
J/A+A/548/A71 : Spectroscopy and ISM detection of formamide (Motiyenko+, 2012)
J/ApJ/717/674 : Ionization energies of CnN(n=4-12) (Kostko+, 2010)
J/A+A/493/687 : Rotational excitation of formaldehyde by H2 (Faure+, 2009)
J/ApJ/678/985 : c2d Spitzer survey of interstellar ices. I. (Boogert+, 2008)
J/ApJS/86/713 : IR spectroscopy of ices (Hudgins+, 1993)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 33 A33 --- Mol Molecular identifier
35 A1 --- f_Mol [e] e: Geometry optimization by MP2/cc-pVTZ
37- 39 I3 --- Mass [30/103] Molecular mass (in u)
41- 51 F11.6 --- UB3LYP [-394/-114.1] B3LYP/cc-pVTZ energy with
zero-point energy correction in hartree (1)
53- 60 F8.6 --- ZPE [0.023/0.091] Zero-point energy by
B3LYP/cc-pVTZ in hartree (1)
62- 73 F12.7 --- CCSD(T) [-393.4/-113.9] CCSD(T)/cc-pVTZ energy (1)
75- 86 F12.7 --- CCSD(T)/CBS [-393.6/-113.9] CCSD(T)/CBS energy (1)
88- 92 F5.2 eV IP1 [0/10.8] Relative ionization potential by
CCSD(T)/cc-pVTZ with B3LYP/cc-pVTZ
zero-point energy correction
94- 98 F5.2 eV IP2 [0/10.9] Relative ionization potential by
CCSD(T)/CBS with B3LYP/cc-pVTZ
zero-point energy correction
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Note (1): The optimized geometries and harmonic frequencies of the molecules
(and its cations) are predicted by the hybrid density functional
B3LYP (Lee et al. 1988PhRvB..37..785L 1988PhRvB..37..785L; Becke 1992JChPh..96.2155B 1992JChPh..96.2155B,
1992JChPh..97.9173B 1992JChPh..97.9173B, 1993JChPh..98.5648B 1993JChPh..98.5648B) level of theory with
the cc-pVTZ basis set. The energies of these species were refined
employing the CCSD(T)/cc-pVTZ with B3LYP/cc-pVTZ zero-point energy
corrections (Purvis & Bartlett 1982JChPh..76.1910P 1982JChPh..76.1910P;
Hampel et al. 1992CPL...190....1H 1992CPL...190....1H; Knowles et al. 1993JChPh..99.5219K 1993JChPh..99.5219K;
Deegan & Knowles 1994CPL...227..321D 1994CPL...227..321D). The energies extrapolated to
complete basis set CCSD(T)/CBS limit were obtained from
Zhu & Lin (2009CPL...478...11Z 2009CPL...478...11Z).
See section 2.2 for further explanations.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 33 A33 --- Mol Molecular identifier
35 A1 --- Atom [CHNO] Atom identifier
37- 45 F9.6 0.1nm X [-3.66/3.57] The X value in Angstroms
47- 55 F9.6 0.1nm Y [-2.79/2.83] The Y value in Angstroms
57- 65 F9.6 0.1nm Z [-3.25/3.25] The Z value in Angstroms
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 33 A33 --- Mol Molecular identifier
35- 42 A8 --- NMode Normal mode (ν1 to ν30)
44- 54 F11.6 cm-1 Freq [23.3/3718.5] Frequency
56- 67 F12.6 --- IRInt [0/27947.5] Infrared intensity
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Jun-2016