Isomeric State Detection
Isomeric State Detection - Related Videos
02:34
Structural Isomerism
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2020
Isomerism in Complexes Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers. Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:43
Isomerism
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2023
Isomers are molecules with the same molecular formula but different structural arrangements. Isomers can be further classified into constitutional isomers and stereoisomers. Constitutional isomers differ in the connectivity of their constituent atoms. For example, 2-butanol and diethyl ether are constitutional isomers, as they have the same chemical formula, C4H10O, but differ in the connectivity of the carbon and oxygen atoms. Constitutional isomers have different physical and chemical...
02:01
Isomerism in Alkenes
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2025
Alkenes like 1-butene and 2-butene exhibit constitutional isomerism, as they differ in the position of the double bond. Further, 2-butene exhibits stereoisomerism and exists as two distinct compounds differing in spatial arrangement. An isomer is called cis-2-butene when the methyl groups are on the same side of the double bond, and the other stereoisomer, in which methyl groups are on the opposite side of the double bond, is called trans-2-butene. The cis and trans stereoisomers are not...
02:37
Disubstituted Cyclohexanes: cis-trans Isomerism
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2023
Depending upon the different spatial orientation of the substituents, the disubstituted cycloalkanes exhibit two types of stereoisomers. The cis isomers have the substituents on the same side of the ring, whereas the trans isomers have the substituents on the opposite sides. These stereoisomers exhibit different physical properties and cannot be interconverted without breaking the carbon-carbon bonds. In cyclohexane, the substituents can occupy different positions generating distinct isomers.
09:10
Combination of Adhesive-tape-based Sampling and Fluorescence in situ Hybridization for Rapid Detection of Salmonella on Fresh Produce
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Cited by 17 •
2010
This protocol describes a simple adhesive-tape-based approach for sampling of tomato and other fresh produce surfaces, followed by rapid whole cell detection of Salmonella using fluorescence in situ hybridization (FISH).
FAQs
The method relies on two linked measurements: the energy of emitted radiation and its arrival time relative to the preceding nuclear event. A delayed gamma ray or internal-conversion electron can be associated with a metastable state when its timing is consistent with the state’s half-life. This correlation separates the transition from radiation produced immediately during the reaction or decay.
Gamma rays and internal-conversion electrons provide different observable signatures of an isomeric transition. Recording either type of radiation can identify the transition, while its measured energy contributes to determining the nuclear excitation energy. Their arrival times also indicate how long the state persists, allowing researchers to characterize delayed decay behavior rather than relying on energy information alone.
An observed transition energy identifies a difference between nuclear energy levels, while the measured lifetime shows how rapidly the isomer decays. Spin-related decay behavior helps explain why a transition may persist rather than occur promptly. Together, these quantities reveal features of nuclear structure and provide evidence for evaluating models of electromagnetic transitions.
A typical measurement records characteristic radiation from the nuclear state, determines the radiation’s energy, and measures when it arrives relative to the relevant nuclear event. Researchers then correlate the energy and timing information with the state’s half-life. This workflow converts a delayed radiation signal into evidence for a particular isomeric transition and its associated nuclear properties.
The technique is useful when a nuclear reaction produces products that include metastable states or long-lived radioactive states. Their delayed radiation provides a way to recognize and characterize those products after the initiating reaction. By examining transition energies and decay times, researchers can connect observed signals with reaction products and investigate the excited-state properties they carry.
Measurements of isomeric transitions help map nuclear structure by supplying excitation energies and level lifetimes, while spin-related decay behavior adds information about how nuclear states connect. These observations also test models of electromagnetic transitions. The resulting data are relevant to broader studies of long-lived radioactive states and the structure of nuclei populated in reactions.