NMR frequency to magnetic field converter circuit with digital readout

Tam, KS; Alani, Alaa; Cohen, E.

doi:10.1088/0022-3735/20/6/027

Cited by 2 publications

(3 citation statements)

References 3 publications

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“…10 The method of rapid deposition uses a large rate of flow (~0.2 mol h -1 ) and condensation onto a substrate maintained~2 K, achieved by pumping liquid helium. 30 The enclosed-cell method suffers from aggregation of guest molecules; concentrations of guest molecules are typically maintained below 100 parts per million (ppm) to avoid formation of clusters, whereas rapid deposition is more versatile for sample preparation but consumption of liquid helium in the continuously pumped cryostat is costly.…”

Section: Deposition Methodsmentioning

confidence: 99%

“…An additional closed-cycle refrigerator system capable of controlling the temperature in the range 10-25 K is required to convert n-H 2 to p-H 2 . The method is well established: 30,32 after passage through a trap at 77 K, H 2 (99.9999%) is passed through the p-H 2 converter before direct deposition or sample mixture preparation. The p-H 2 converter comprises a copper cell filled with APACHI (a paramagnetic nickel salt supported on particulate silica gel) or hydrated ferric (III) oxide catalyst and cooled with a closed-cycle refrigerator.…”

Section: Conversion Of P-h 2 From N-hmentioning

confidence: 99%

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Advances in Use of p‐H₂ as a Novel Host for Matrix IR Spectroscopy

Bahou¹,

Huang²,

Huang³

et al. 2010

J Chinese Chemical Soc

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A review of recent advances in IR spectroscopy using p-H 2 as a matrix host in our laboratory is presented. The softness of this novel p-H 2 matrix host not only makes high-resolution spectroscopy feasible but also provides new applications. Molecular motion, such as the rotation of C 2 H 4 , internal rotation (torsion) of CH 3 OH, and rotation of CH 3 F about a single axis are characterized in this p-H 2 matrix. In contrast, no evidence for rotation of CH 3 I and CH 3 was found. The diminution of the cage effect leads to the possibility of production of free radicals via either photolysis in situ or bimolecular reactions of molecules with atoms that are produced in situ from their molecular precursors. Taking advantage of these unique features, we identified the IR spectrum of CH 3 produced from photolysis of CH 3 I and CH 3 S produced from photolysis of CH 3 SCH 3 and CH 3 SSCH 3 . The reaction of Cl with CS 2 in solid p-H 2 yields ClSCS instead of ClCS 2 . The reaction of Cl with HCOOH in solid p-H 2 yields only a complex, Cl×HCOOH, not HCl and HOCO. The presence of o-H 2 in trace proportions turned out to be an important factor in the interpretation of IR spectra of species embedded in solid p-H 2 . Experimental techniques to minimize the amount of o-H 2 and to characterize its relative concentration with spectra of H 2 O×o-H 2 are discussed.

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Section: Deposition Methodsmentioning

confidence: 99%

Section: Conversion Of P-h 2 From N-hmentioning

confidence: 99%

Advances in Use of p‐H₂ as a Novel Host for Matrix IR Spectroscopy

Bahou¹,

Huang²,

Huang³

et al. 2010

J Chinese Chemical Soc

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“…65 A p-H 2 matrix is also an ideal medium to investigate tunneling reactions at low temperature; reactions between CH 3 and H2, and their deuterated variants have generated interesting results. 66 Two methods have commonly served to prepare a p-H 2 matrix for IR absorption spectroscopy: the enclosed-cell method utilizes condensation of a flow of a gaseous mixture containing p-H 2 and a species of interest in an enclosed cell maintained at~8 K to form transparent crystalline p-H 2 , 63 and the rapid deposition method uses a large rate of flow (~0.2 mol h -1 ) for condensation onto a target maintained~2 K. 67 The enclosed-cell method suffers from aggregation of guest molecules; concentrations of guest molecules are typically maintained below 100 parts per million (ppm) to avoid formation of clusters. Direct preparation of labile species isolated in p-H 2 is limited to photolysis in situ of matrix samples containing precursors.…”

Section: Using P-h 2 As a Matrix Hostmentioning

confidence: 99%

Preparation and Spectral Characterization of Novel Species in Matrices

Lee

2005

Jnl Chinese Chemical Soc

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A review of matrix-isolation experiments performed in this laboratory for the past thirteen years (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)) is given; the work emphasizes the preparation and spectral characterization of novel species of atmospheric interest, and the significance of detection of some species is discussed. A previous review (J. Chin. Chem. Soc. 1992, 39, 503) covers work from 1981 to 1991. Various methods for production of novel species, including reaction in the gaseous phase, laser photolysis of a single precursor in situ, reaction of a molecule with an atom or radical in a matrix cage and reaction of a molecule with an electronically excited molecule, are discussed. The effect of secondary photolysis on products is illustrated with formation of various conformers of HOONO from photolysis of HNO3. The advantage of investigating electronic transitions that are difficult to observe in the gaseous phase and the mode and site selectivity of photodissociation for species in a matrix cage are also discussed. New developments involving use of p-H2 as a matrix host, including the introduction of a pulse-deposition method for use at~5 K and the exploration of internal rotation of larger molecules in solid p-H2, are also presented.

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NMR frequency to magnetic field converter circuit with digital readout

Cited by 2 publications

References 3 publications

Advances in Use of p‐H₂ as a Novel Host for Matrix IR Spectroscopy

Advances in Use of p‐H₂ as a Novel Host for Matrix IR Spectroscopy

Preparation and Spectral Characterization of Novel Species in Matrices

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NMR frequency to magnetic field converter circuit with digital readout

Cited by 2 publications

References 3 publications

Advances in Use of p‐H2 as a Novel Host for Matrix IR Spectroscopy

Advances in Use of p‐H2 as a Novel Host for Matrix IR Spectroscopy

Preparation and Spectral Characterization of Novel Species in Matrices

Contact Info

Product

Resources

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Advances in Use of p‐H₂ as a Novel Host for Matrix IR Spectroscopy

Advances in Use of p‐H₂ as a Novel Host for Matrix IR Spectroscopy