Related Experiment Video
Updated: Sep 22, 2025
Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Excited Electronic State Cross Sections for Group 3 Halide and Oxide Production: Evaluating Relative Excited-State
Carl L Chalek1, James L Gole1, David A Dixon2
1School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, Unites States.
Abstract:
The cross sections for excited-state formation from the reactions of the group 3 metals, Sc, Y, and La, with F2 and NO2, are evaluated from experimental data. Detailed calibrations indicate that the cross sections for MF formation greatly exceed those for MO formation. The experimentally determined cross sections are compared to upper bounds for total reactive cross sections. Based on this comparison, the ratios of excited state to ground state product formation (quantum yield) are evaluated. The reactions of Sc and Y with F2, which produce excited states selectively, may represent candidates to create a population inversion for use in a chemical laser.
Related Concept Videos
03:01Halogens
01:22Mass Spectrometry: Alkyl Halide Fragmentation
02:45Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
02:48Ionic Bonding and Electron Transfer
02:38Electrophilic Addition to Alkynes: Halogenation
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
02:26SN2 Reaction: Transition State
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...