Delayed γ-ray cascades, originating from the decay of (6⁺) isomeric states, in the very neutron-rich, semimagic isotopes (136,138)Sn have been observed following the projectile fission of a ²³⁸U beam at RIBF, RIKEN. The wave functions of these isomeric states are proposed to be predominantly a fully aligned pair of f(7/2) neutrons. Shell-model calculations, performed using a realistic effective interaction, reproduce well the energies of the excited states of these nuclei and the measured transition rates, with the exception of the B(E2;6⁺→4⁺) rate of ¹³⁶Sn, which deviates from a simple seniority scheme. Empirically reducing the νf(7/2)(2) orbit matrix elements produces a 4₁⁺ state with almost equal seniority 2 and 4 components, correctly reproducing the experimental B(E2;6⁺→4⁺) rate of ¹³⁶Sn. These data provide a key benchmark for shell-model interactions far from stability.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.113.132502 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
From Beam Damage to Massive Reaction Amplification under the Electron Microscope: An Ionization-Induced Chain Reaction in Crystals of a Dewar Benzene.
ACS Cent Sci
December 2024
Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90095, United States.
Electron microscopy in its various forms is one of the most powerful imaging and structural elucidation methods in nanotechnology where sample information is generally limited by random chemical and structural damage. Here we show how a well-selected chemical probe can be used to transform indiscriminate chemical damage into clean chemical processes that can be used to characterize some aspects of the interactions between high-energy electron beams and soft organic matter. Crystals of a Dewar benzene exposed to a 300 keV electron beam facilitate a clean valence-bond isomerization radical-cation chain reaction where the number of chemical events per incident electron is amplified by a factor of up to ca.
View Article and Find Full Text PDFHighly Efficient Analysis on Biomass Carbohydrate Mixtures by DREAMTIME NMR Spectroscopy.
Anal Chem
December 2024
Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Siming South Road 422, Xiamen 361005, China.
Proton (H) NMR spectroscopy presents a powerful tool for biomass mixture studies by revealing the involved chemical compounds with identified ingredients and molecular structures. However, conventional H NMR generally suffers from spectral congestion when measuring biomass mixtures, particularly biomass carbohydrate samples, that contain various physically and chemically similar compounds. In this study, a targeted detection NMR approach, DREAMTIME, is exploited for studying biomass carbohydrate mixtures by spectroscopically targeting the desired compounds in separate 1D NMR spectra.
View Article and Find Full Text PDFCompartmentalizing Donor-Acceptor Stenhouse Adducts for Structure-Property Relationship Analysis.
J Am Chem Soc
December 2024
Department of Chemistry, Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, California 90089, United States.
The development of photoswitches that absorb low energy light is of notable interest due to the growing demand for smart materials and therapeutics necessitating benign stimuli. Donor-acceptor Stenhouse adducts (DASAs) are molecular photoswitches that respond to light in the visible to near-infrared spectrum. As a result of their modular assembly, DASAs can be modified at the donor, acceptor, triene, and backbone heteroatom molecular compartments for the tuning of optical and photoswitching properties.
View Article and Find Full Text PDFPhotoinduced Reductive C-O Couplings from Unsymmetrical Bis-Cyclometalated Pt(IV) Dicarboxylato Complexes.
Inorg Chem
December 2024
Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo 19, Murcia 30100, Spain.
Unsymmetrical bis-cyclometalated dicarboxylato complexes (-6-32)-[Pt(tpy)(OCR)] [tpy = cyclometalated 2-(-tolyl)pyridine, R = -Bu (), Me (), Ph (), CF ()], are obtained from the reaction of -[Pt(tpy)] with the appropriate PhI(OCR) reagent. Treatment of complexes of this type with different carboxylates (R'CO) results in the formation of mixed-carboxylato derivatives, namely (-6-43)-[Pt(tpy)(OCMe)(OCR')] [R' = -Bu (), CF (), Ph ()], (-6-34)-[Pt(tpy)(OCCF)(OCR')] [R' = -Bu (), Me (), Ph ()], and (-6-34)-[Pt(tpy)(OC--Bu)(OCMe)] (). Irradiation of - and - with UV light (365 nm) in MeCN gives 5-methyl-2-(2-pyridyl)phenyl pivalate (), 5-methyl-2-(2-pyridyl)phenyl acetate () or 5-methyl-2-(2-pyridyl)phenyl benzoate () as the major photoproduct from most complexes, resulting from a reductive C-O coupling between a tpy ligand and a carboxylato ligand.
View Article and Find Full Text PDFAssembly of Pyrenes through a Quadruple Photochemical Cascade: Blocking Groups Allow Diversion from the Double Mallory Path to Photocyclization at the Bay Region.
J Am Chem Soc
December 2024
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.
We present a six-step cascade that converts 1,3-distyrylbenzenes (-stilbenes) into nonsymmetric pyrenes in 40-60% yields. This sequence merges photochemical steps, ,-alkene isomerization, a 6π photochemical electrocyclization (Mallory photocyclization); the new bay region cyclization, with two radical iodine-mediated aromatization steps; and an optional aryl migration. This work illustrates how the inherent challenges of engineering excited state reactivity can be addressed by logical design.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!