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 04:00:00 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]

---

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

Related Subjects

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