scholarly journals Synthesis and Spectroscopy of Buckminsterfullerene Cation C60+ in a Cryogenic Ion Trapping Instrument

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1119
Author(s):  
Ewen K. Campbell ◽  
Johanna Rademacher ◽  
Saida M. M. Bana
Keyword(s):  
Low Temperature ◽  
Near Infrared ◽  
Spectroscopic Properties ◽  
Ion Trapping ◽  
High Abundance ◽  
Astronomical Observations ◽  
Diffuse Interstellar Bands ◽  
Laser Vaporisation ◽  
Derivatives Of ◽  
Spectroscopic Characterisation

The assignment of several diffuse interstellar bands in the near-infrared to C60+ ions present at high abundance in space has renewed interest in the astrochemical importance of fullerenes and analogues. Many of the latter have not been produced in macroscopic quantities, and their spectroscopic properties are not available for comparison with astronomical observations. An apparatus has been constructed that combines laser vaporisation synthesis with spectroscopic characterisation at low temperature in a cryogenic trap. This instrument is used here to record the electronic absorptions of C60+ produced by laser vaporisation of graphite. These are detected by (helium tagged) messenger spectroscopy in a cryogenic trap. By comparison with spectra obtained using a sublimed sample of Buckminsterfullerene, the observed data show that this isomer is the dominant C60+ structure tagged with helium at m/z=724, indicating that the adopted approach can be used to access the spectra of other fullerenes and derivatives of astrochemical interest.

The Through-Bond Interaction of a Sulfur Lone Pair with Oxygenated Substituents in the Thiacyclohexane Framework

2005 ◽  
Vol 58 (7) ◽  
pp. 531
Author(s):  
Laura Andrau ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Crystal Structures ◽  
Bond Distance ◽  
Lone Pair ◽  
X Ray ◽  
Ester Derivative ◽  
Bond Interaction ◽  
Derivatives Of ◽  
Electron Demand

Low-temperature X-ray crystal structures were determined on a range of derivatives of 4-thiacyclohexanol 5a of varying electron demand with a view to finding evidence for a through-bond interaction between the sulfur lone pair and the oxygenated substituent. In contrast to earlier suggestions, plots of C–OR bond distance versus pKa (ROH) showed that any interaction between the sulfur and the OR group is unlikely to be of a through-bond origin. Furthermore, unimolecular solvolysis rate measurements on the nosylate ester derivative 5g showed that the sulfur actually retards the reaction slightly in comparison with the corresponding sulfur-free analogue 6.

Triazene derivatives of (1,x-)diazacycloalkanes. Part VI. 3-({5,5-Dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines — Synthesis, characterization, and X-ray crystal structure

2006 ◽  
Vol 84 (10) ◽  
pp. 1294-1300 ◽  
Author(s):  
Keith Vaughan ◽  
Shasta Lee Moser ◽  
Reid Tingley ◽  
M Brad Peori ◽  
Valerio Bertolasi
Keyword(s):  
Crystal Structure ◽  
Significant Degree ◽  
Ion Trapping ◽  
Published Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Diazonium Ion ◽  
Derivatives Of ◽  
C Nmr

Reaction of a series of diazonium salts with a mixture of formaldehyde and 1,2-diamino-2-methylpropane affords the 3-({5,5-dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines (1a–1f) in excellent yield. The products have been characterized by IR and NMR spectroscopic analysis, elemental analysis, and X-ray crystallography. The X-ray crystal structure of the p-methoxycarbonyl derivative (1c) establishes without question the connectivity of these novel molecules, which can be described as linear bicyclic oligomers with two imidazolidinyl groups linked together by a one-carbon spacer. This is indeed a rare molecular building block. The molecular structure is corroborated by 1H and 13C NMR data, which correlates with the previously published data of compounds of types 5 and 6 derived from 1,3-propanediamine. The triazene moieties in the crystal of 1c display significant π conjugation, which gives the N—N bond a significant degree of double-bond character. This in turn causes restricted rotation around the N—N bond, which leads to considerable broadening of signals in both the 1H and 13C NMR spectra. The molecular ion of the p-cyanophenyl derivative (1b) was observed using electrospray mass spectrometry (ES + Na). The mechanism of formation of molecules of type 1 is proposed to involve diazonium ion trapping of the previously unreported bisimidazolidinyl methane (13).Key words: triazene, bistriazene, imidazolidine, synthesis, X-ray crystallography, NMR spectroscopy.

scholarly journals VLT/X-Shooter survey of near-infrared diffuse interstellar bands

2014 ◽  
Vol 569 ◽  
pp. A117 ◽  
Author(s):  
N. L. J. Cox ◽  
J. Cami ◽  
L. Kaper ◽  
P. Ehrenfreund ◽  
B. H. Foing ◽  
...  
Keyword(s):  
Near Infrared ◽  
Diffuse Interstellar Bands

Carbonization in Titan Tholins: implication for low albedo on surfaces of Centaurs and trans-Neptunian objects

2015 ◽  
Vol 15 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Chaitanya Giri ◽  
Christopher P. McKay ◽  
Fred Goesmann ◽  
Nadine Schäfer ◽  
Xiang Li ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Organic Material ◽  
Near Infrared ◽  
Proof Of Concept ◽  
Astronomical Observations ◽  
Polycyclic Aromatic ◽  
Large Polycyclic Aromatic Hydrocarbons ◽  
Characteristic Features ◽  
Complex Organic ◽  
Geometric Albedo

AbstractAstronomical observations of Centaurs and trans-Neptunian objects (TNOs) yield two characteristic features – near-infrared (NIR) reflectance and low geometric albedo. The first feature apparently originates due to complex organic material on their surfaces, but the origin of the material contributing to low albedo is not well understood. Titan tholins synthesized to simulate aerosols in the atmosphere of Saturn's moon Titan have also been used for simulating the NIR reflectances of several Centaurs and TNOs. Here, we report novel detections of large polycyclic aromatic hydrocarbons, nanoscopic soot aggregates and cauliflower-like graphite within Titan tholins. We put forth a proof of concept stating the surfaces of Centaurs and TNOs may perhaps comprise of highly ‘carbonized’ complex organic material, analogous to the tholins we investigated. Such material would apparently be capable of contributing to the NIR reflectances and to the low geometric albedos simultaneously.

scholarly journals Near-infrared diffuse interstellar bands towards Her 36

2019 ◽  
Vol 485 (3) ◽  
pp. 3398-3401
Author(s):  
M G Rawlings ◽  
A J Adamson ◽  
C C M Marshall ◽  
P J Sarre
Keyword(s):  
Near Infrared ◽  
Diffuse Interstellar Bands

scholarly journals Reproduction of the Interstellar Ice Band by Grain Mantle Analogs

1980 ◽  
Vol 87 ◽  
pp. 387-388
Author(s):  
W. Hagen ◽  
A.G.G.M. Tielens ◽  
J. M. Greenberg
Keyword(s):  
Low Temperature ◽  
Interstellar Dust ◽  
Near Infrared ◽  
Absorption Feature ◽  
Band Shape ◽  
Interstellar Ice ◽  
Infrared Spectrometer ◽  
Simple Molecules ◽  
Many Sources ◽  
Dust Grain

The near-infrared spectrum of many sources associated with molecular clouds shows a broad absorption feature at 3.08 μm (e.g. Merrill et al., 1976; Harris et al., 1978). This feature has usually been attributed to absorption by H2O ice frozen on grains, but it has been impossible to satisfactorily reproduce the observed band shape (Merrill et al., 1976; Mukai et al., 1978). We have been able to obtain a complete fit of this absorption feature in the laboratory using very low temperature mixtures of H2O with other polar molecules. The preparation of these interstellar dust grain-mantle analogs has been described elsewhere (Greenberg, 1979; Hagen et al., 1979). They are prepared by allowing a gas mixture of simple molecules (e.g. CO, H2O, NH3, CH4 etc.) to condense on a low temperature (10 K) substrate. This frozen mixture can be heated and recooled. The samples are analyzed with an infrared spectrometer.

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