The Gas Phase Anisole Dimer: A Combined High-Resolution Spectroscopy and Computational Study of a Stacked Molecular System†

2009 ◽  
Vol 113 (52) ◽  
pp. 14343-14351 ◽  
Author(s):  
G. Pietraperzia ◽  
M. Pasquini ◽  
N. Schiccheri ◽  
G. Piani ◽  
M. Becucci ◽  
...  
2018 ◽  
Vol 9 (7) ◽  
pp. 1497-1502 ◽  
Author(s):  
Iciar Uriarte ◽  
Sonia Melandri ◽  
Assimo Maris ◽  
Camilla Calabrese ◽  
Emilio J. Cocinero

2004 ◽  
Vol 120 (24) ◽  
pp. 11351-11354 ◽  
Author(s):  
Joseph R. Roscioli ◽  
David W. Pratt ◽  
Zorka Smedarchina ◽  
Willem Siebrand ◽  
Antonio Fernández-Ramos

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1200-1205 ◽  
Author(s):  
Mingguang Li ◽  
John A. Coxon

The [Formula: see text] (000)–(000) band of the gas-phase CaOD radical has been rotationally analyzed using high-resolution laser spectroscopy. The technique of intermodulated fluorescence was employed to resolve the small spin-rotation splittings in the ground state. The measurement accuracy of the rotational line positions was 0.003 cm−1. The measured line positions have been employed in a least-squares estimation of the molecular constrants for both electronic states. Isotope relations between the constants of CaOH and CaOD are examined, and the constants AD and γ for the Ã2Π(000) level were separated using isotope effects.


1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.


2017 ◽  
Author(s):  
Robson de Farias

<p>In the present work, a computational study is performed in order to clarify the possible magnetic nature of gold. For such purpose, gas phase Au<sub>2</sub> (zero charge) is modelled, in order to calculate its gas phase formation enthalpy. The calculated values were compared with the experimental value obtained by means of Knudsen effusion mass spectrometric studies [5]. Based on the obtained formation enthalpy values for Au<sub>2</sub>, the compound with two unpaired electrons is the most probable one. The calculated ionization energy of modelled Au<sub>2</sub> with two unpaired electrons is 8.94 eV and with zero unpaired electrons, 11.42 eV. The difference (11.42-8.94 = 2.48 eV = 239.29 kJmol<sup>-1</sup>), is in very good agreement with the experimental value of 226.2 ± 0.5 kJmol<sup>-1</sup> to the Au-Au bond<sup>7</sup>. So, as expected, in the specie with none unpaired electrons, the two 6s<sup>1</sup> (one of each gold atom) are paired, forming a chemical bond with bond order 1. On the other hand, in Au<sub>2</sub> with two unpaired electrons, the s-d hybridization prevails, because the relativistic contributions. A molecular orbital energy diagram for gas phase Au<sub>2</sub> is proposed, explaining its paramagnetism (and, by extension, the paramagnetism of gold clusters and nanoparticles).</p>


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