Laser vaporization generation of Al sup 12 C, Al sup 13 C, Al sup 12 C sub 2 , and Al sup 13 C sub 2 for rare gas matrix electron spin resonance studies: Experimental--theoretical comparisons

Journal Article · Tue May 15 00:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.458355· OSTI ID:6850402

Knight, Jr, L B; Cobranchi, S T; Herlong, J O; Arrington, C A ^[1]

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1. Chemistry Department, Furman University, Greenville, South Carolina 29613 (USA)

The metal carbide radicals AlC and AlC{sub 2} have been generated by the laser vaporization of aluminum carbide and trapped in neon and argon matrices at 4 K for electron spin resonance (ESR) characterization. These results provide the first experimental evidence showing that AlC has a {sup 4}{Sigma} ground electronic state and that AlC{sub 2} is {ital X} {sup 2}{ital A}{sub 1}. {ital Ab} {ital initio} theoretical calculations were conducted for the geometries and various nuclear hyperfine parameters in both radicals which yielded {ital A} values in reasonable agreement with the observed. In AlC, the three unpaired electrons reside primarily on carbon with the following neon matrix magnetic parameters (MHz): {ital g}{sub {parallel}}=2.000(1); {ital g}{sub {perpendicular}}=2.0010(5); {vert bar}{ital A}{sub {perpendicular}}(Al){vert bar}=33.2(5); {vert bar}{ital A}{sub {parallel}}(Al){vert bar}=3(3); {ital A}{sub {perpendicular}}({sup 13}C)=52.1(5); {ital A}{sub {parallel}}({sup 13}C)=52(2); and {ital D}(zero field splitting)=374(1). For AlC{sub 2}, the spin density resides predominantly in an aluminum 3{ital p}{sub {ital z}}/3{ital s} hybrid directed away from C{sub 2}. The neon magnetic parameters (MHz) are: {ital g}{sub {parallel}}=2.0005(5); {ital g}{sub {perpendicular}}=1.9965(3); {ital A}{sub {perpendicular}}(Al)=941.5(5); {ital A}{sub {parallel}}(Al)=1067(1); {vert bar}{ital A}{sub {parallel}}({sup 13}C){vert bar}=59(1); and {vert bar}{ital A}{sub {perpendicular}}({sup 13}C){vert bar}=52(1).

• OSTI ID: 6850402
• Journal Information: Journal of Chemical Physics; (USA), Vol. 92:10; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ALUMINIUM 27
HYPERFINE STRUCTURE
ALUMINIUM CARBIDES
ELECTRON SPIN RESONANCE
CARBON 13
ELECTRONIC STRUCTURE
EVAPORATION
LASER RADIATION
MATRIX ISOLATION
RADICALS
ALUMINIUM COMPOUNDS
ALUMINIUM ISOTOPES
CARBIDES
CARBON COMPOUNDS
CARBON ISOTOPES
ELECTROMAGNETIC RADIATION
EVEN-ODD NUCLEI
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
PHASE TRANSFORMATIONS
RADIATIONS
RESONANCE
STABLE ISOTOPES
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory