Über Para- und Orthowasserstoff

Bonhoeffer, K. F.; Harteck, P.

doi:10.1515/zpch-1929-0408

Cited by 132 publications

(43 citation statements)

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“…The probability distribution j y (1) (f,t) j 2 at different times is shown in Figure 4. We choose a pulse with t p = 3 fs which induces a vertical transition.…”

Section: Dynamics Of a Torsional Wavepacketmentioning

confidence: 99%

“…The experimental evidence for the existence of two different nuclear spin states in hydrogen molecules, para-and ortho-hydrogen, was a landmark in the foundation of quantum mechanics. [1] It is of both practical and conceptual importance to prepare pure nuclear spin states. From the conceptual viewpoint, the spin provides an interesting manifestation of the role of non-integer angular momenta in quantum mechanics.…”

Section: Introductionmentioning

confidence: 99%

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Toward Separation of Nuclear Spin Isomers with Coherent Light

et al. 2007

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We propose an approach for separating nuclear spin isomers with coherent light and illustrate it by numerical calculations using fulvene as a model system. The scheme employs the equivalence of torsion and interchange of equivalent H-atoms in a class of molecules of which fulvene is a simple example. The exchange symmetry couples with the rotational symmetry to produce a spatial distinction between the two photo-excited nuclear spin isomers, and wavepacket interferometry is applied to separate the species.

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“…The probability distribution j y (1) (f,t) j 2 at different times is shown in Figure 4. We choose a pulse with t p = 3 fs which induces a vertical transition.…”

Section: Dynamics Of a Torsional Wavepacketmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Toward Separation of Nuclear Spin Isomers with Coherent Light

et al. 2007

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“…This is indeed what happened with the textbook example of the Gibbs paradox situation, ortho and para hydrogen, cf. Bonhoeffer & Harteck [20], Farkas [43]. Hydrogen seemed at first to be a single substance, but then thermodynamic data forced a refined description.…”

Section: Example (The Gibbs Paradox)mentioning

confidence: 99%

Foundations of Thermodynamics

Hardy¹,

Binek²

2014

Thermodynamics and Statistical Mechanics

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Abstract. On the basis of new, concise foundations, this paper establishes the four laws of thermodynamics, the Maxwell relations, and the stability requirements for response functions, in a form applicable to global (homogeneous), local (hydrodynamic) and microlocal (kinetic) equilibrium.The present, self-contained treatment needs very little formal machinery and stays very close to the formulas as they are applied by the practicing physicist, chemist, or engineer. From a few basic assumptions, the full structure of phenomenological thermodynamics and of classical and quantum statistical mechanics is recovered.Care has been taken to keep the foundations free of subjective aspects (which traditionally creep in through information or probability). One might describe the paper as a uniform treatment of the nondynamical part of classical and quantum statistical mechanics "without statistics" (i.e., suitable for the definite descriptions of single objects) and "without mechanics" (i.e., independent of microscopic assumptions). When enriched by the traditional examples and applications, this paper may serve as the basis for a course on thermal physics.

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“…This is readily achieved by cooling H 2 in the presence of a paramagnetic species. The degree of enrichment simply depends on the temperature of the catalyst; 50% enrichment is possible at 77 K. [3,4] An important feature of parahydrogen (p-H 2 ) is that it is NMR silent. However, if it adds to a metal centre in such a way that two chemically distinct hydrides are formed, the energy level diagram shown in Figure 1 is obtained.…”

Section: Principles Behind the Parahydrogen Effectmentioning

confidence: 99%

“…[44] The reaction of phenylacetylene with hy- drogen using the colloidal palladium catalyst Pd x [N(octyl) 4 Cl] y was observed to yield enhanced signals in the product species. In another study, PHIP was used to study reversible H 2 adsorption on ZnO.…”

Section: Other Developmentsmentioning

confidence: 99%

The Study of Inorganic Systems by NMR Spectroscopy in Conjunction with Parahydrogen‐Induced Polarisation

Duckett

Blazina

2003

Eur J Inorg Chem

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The study of reaction mechanisms by NMR spectroscopy normally suffers from limitations in sensitivity that result in substantial difficulties in the detection and characterisation of reaction intermediates. One technique that can circumvent this problem is the use of para‐enriched hydrogen. Here, an overview of the developments in the study of chemical reactions using parahydrogen‐assisted NMR spectroscopy is presented, with the characterisation of a number of new hydride complexes of iridium, rhodium, ruthenium and tantalum being described. A number of studies involving transition metal clusters and catalytic applications are also considered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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Über Para- und Orthowasserstoff

Cited by 132 publications

References 0 publications

Toward Separation of Nuclear Spin Isomers with Coherent Light

Toward Separation of Nuclear Spin Isomers with Coherent Light

Foundations of Thermodynamics

The Study of Inorganic Systems by NMR Spectroscopy in Conjunction with Parahydrogen‐Induced Polarisation

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