Spectroscopic Identification of Carbenium and Ammonium Isomers of Protonated Aniline (AnH+):  IR Spectra of Weakly Bound AnH+−LnClusters (L = Ar, N2)

2006 ◽  
Vol 110 (47) ◽  
pp. 12793-12804 ◽  
Author(s):  
Felix M. Pasker ◽  
Nicola Solcà ◽  
Otto Dopfer
Keyword(s):  
Ir Spectra ◽  
Weakly Bound ◽  
Spectroscopic Identification ◽  
Protonated Aniline

Evolution of IR spectra of a weakly-bound OCO⋯HCl complex with increasing CO2 density from the gas to liquid phase

2001 ◽  
Vol 598 (2-3) ◽  
pp. 205-211 ◽  
Author(s):  
K.S Rutkowski ◽  
K.G Tokhadze ◽  
P Lipkowski ◽  
A Koll ◽  
R Ahmedjonov ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Ir Spectra ◽  
Weakly Bound ◽  
Gas To Liquid ◽  
Co2 Density

Infrared spectra of carbocations and CH4+ in helium

2021 ◽  
Author(s):  
Julia Ann Davies ◽  
Shengfu Yang ◽  
Andrew M Ellis
Keyword(s):  
Ir Spectra ◽  
Infrared Spectra ◽  
Electron Ionization ◽  
Weakly Bound ◽  
Cation Complexes

Infrared (IR) spectra of several hydrocarbon cations are reported, namely CH3+, CH4+, CH5+, CH5+(CH4) and C2H5+. The spectra were generated from weakly-bound helium-cation complexes formed by electron ionization of helium...

scholarly journals Production of Carbamic Acid Dimer from Ammonia-Carbon Dioxide Ices: Matching Observed and Computed IR Spectra

Life ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 34 ◽  
Author(s):  
Altun ◽  
Bleda ◽  
Trindle
Keyword(s):  
Carbon Dioxide ◽  
Ir Spectra ◽  
Vibrational Spectra ◽  
Carbamic Acid ◽  
Weakly Bound ◽  
Complex Molecules ◽  
Ammonium Carbamate ◽  
Ammonia Complex ◽  
Pass Through ◽  
Spectrum Matching

The production of complex molecules in ammonia–carbon dioxide ices is presumed to pass through species of formula H3N:CO2 with further addition of ammonia and carbon dioxide. One possible landmark, carbamic acid, H2NCOOH, has been implicated among the products of warming and irradiation of such ices. Experimental study of the IR spectra of residues has suggested the presence of related species, including weakly bound 1:1 and 2:1 complexes of ammonia with carbon dioxide, zwitterionic carbamic acid, ammonium carbamate, and the dimer of carbamic acid. We computed the energetics and vibrational spectra of these species as well as the complex between ammonia and carbamic acid for gas and condensed phases. By means of a new spectrum-matching scoring between computed and observed vibrational spectra, we infer species that are most probably present. The leading candidates are ammonium carbamate, the carbamic acid–ammonia complex, and the carbamic acid dimer.

Long-path equilibrium IR spectra of weakly bound complexes at low temperatures

1994 ◽  
Vol 97 ◽  
pp. 69 ◽  
Author(s):  
A. Robert W. McKellar
Keyword(s):  
Ir Spectra ◽  
Low Temperatures ◽  
Weakly Bound ◽  
Weakly Bound Complexes

CRYO-Electron Microscopy of the Acto-Myosin-ATP Complex

1990 ◽  
Vol 48 (1) ◽  
pp. 248-249
Author(s):  
John Trinickt ◽  
Howard White
Keyword(s):  
Electron Microscopy ◽  
Atp Hydrolysis ◽  
Myosin Head ◽  
Bound State ◽  
Cross Linking ◽  
Weakly Bound ◽  
Cryo Electron Microscopy ◽  
Myosin Subfragment 1 ◽  
Attached State ◽  
High Fraction

The primary force of muscle contraction is thought to involve a change in the myosin head whilst attached to actin, the energy coming from ATP hydrolysis. This change in attached state could either be a conformational change in the head or an alteration in the binding angle made with actin. A considerable amount is known about one bound state, the so-called strongly attached state, which occurs in the presence of ADP or in the absence of nucleotide. In this state, which probably corresponds to the last attached state of the force-producing cycle, the angle between the long axis myosin head and the actin filament is roughly 45°. Details of other attached states before and during power production have been difficult to obtain because, even at very high protein concentration, the complex is almost completely dissociated by ATP. Electron micrographs of the complex in the presence of ATP have therefore been obtained only after chemically cross-linking myosin subfragment-1 (S1) to actin filaments to prevent dissociation. But it is unclear then whether the variability in attachment angle observed is due merely to the cross-link acting as a hinge.We have recently found low ionic-strength conditions under which, without resorting to cross-linking, a high fraction of S1 is bound to actin during steady state ATP hydrolysis. The structure of this complex is being studied by cryo-electron microscopy of hydrated specimens. Most advantages of frozen specimens over ambient temperature methods such as negative staining have already been documented. These include improved preservation and fixation rates and the ability to observe protein directly rather than a surrounding stain envelope. In the present experiments, hydrated specimens have the additional benefit that it is feasible to use protein concentrations roughly two orders of magnitude higher than in conventional specimens, thereby reducing dissociation of weakly bound complexes.

Spectral characteristics of the weakly bound electron species in methanol as determined from a hybrid solvation model

1996 ◽  
Vol 93 ◽  
pp. 182-187 ◽  
Author(s):  
C Pépin ◽  
T Goulet ◽  
D Houde ◽  
JP Jay-Gerin
Keyword(s):  
Spectral Characteristics ◽  
Solvation Model ◽  
Weakly Bound ◽  
Bound Electron
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