EPR studies of S(M(CO) sub 5 ) sub 2 sup minus radicals (M = Cr, W) trapped in single crystals of PPN sup + HS(M(CO) sub 5 ) sub 2 sup minus

Journal Article · Mon Dec 31 23:00:00 EST 1990 · Organometallics; (United States)

DOI:https://doi.org/10.1021/om00047a047· OSTI ID:6070205

Hynes, R C; Preston, K F; Springs, J J; Williams, A J ^[1]

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1. National Research Council of Canada, Ottawa, Ontario (Canada)

Persistent anisotropic EPR spectra detected in {gamma}-irradiated single crystals of PPN{sup +}HSM{sub 2}(CO){sub 10}{sup {minus}} (M = Cr, W) are attributed to the anion radicals produced by loss of a hydrogen atom from the undamaged anions. The g tensors were determined from measurements taken throughout three mutually orthogonal planes of crystallographically aligned single-crystal specimens: g(Cr) = (2.0008, 2.1142, 2.0472); g(W) = (1.9899, 2.2461, 2.0900). X-ray diffractometry showed that the undamaged crystals were isomorphous and belonged to the triclinic space group P{bar 1}. A full structure determination was carried out for the Cr compound only. Cell parameters for the Cr compound are as follows: a = 9.6629 (10) {angstrom}, b = 14.1626 (11) {angstrom}, c = 16.9509 (14) {angstrom}, {alpha} = 78.226 (7){degree}, {beta} = 85.711 (8){degree}, {gamma} = 89.615 (8){degree}, Z = 2. Cell parameters for the W compound are as follows: a = 9.825 (2) {angstrom}, b = 14.097 (4) {angstrom}, c = 17.019 (9) {angstrom}, {alpha} = 78.47 (3){degree}, {beta} = 85.72 (3){degree}, {gamma} = 89.91 (2){degree}. The anion structures showed an approximately octahedral arrangement of five carbonyls and a (shared) sulfur about each metal atom. Carbonyls from opposite ends of the anion are staggered with respect to each other. Cr-S bonds are 2.46 and 2.48 {angstrom} long and 122.8{degree} apart. A good correlation was established for both Cr- and W-containing crystals between principal g values and the M-M direction (maximum g), the bisector of the M-S-M angle (intermediate g), and the perpendicular to the MSM plane (minimum g). The observations are interpreted in terms of a {pi}'-radical structure, analogous to that of SO{sub 2}{sup {minus}} in which unpaired spin density is shared between a S 3p{sub x} orbital directed perpendicular to the CrSCr plane and Cr 3d{sub xz} orbitals.

• OSTI ID: 6070205
• Journal Information: Organometallics; (United States), Journal Name: Organometallics; (United States) Vol. 10:1; ISSN 0276-7333; ISSN ORGND
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BOND ANGLE
BOND LENGTHS
CARBONYL RADICALS
CHALCOGENIDES
CHEMICAL PREPARATION
CHROMIUM COMPLEXES
COBALT 60
COBALT ISOTOPES
COHERENT SCATTERING
COMPLEXES
DIFFRACTION
DIMENSIONS
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
GAMMA RADIATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LENGTH
MAGNETIC RESONANCE
MINUTES LIVING RADIOISOTOPES
MOLECULAR STRUCTURE
NITRIDES
NITROGEN COMPOUNDS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHOSPHORUS COMPOUNDS
PHOSPHORUS NITRIDES
PNICTIDES
RADIATIONS
RADICALS
RADIOISOTOPES
RESONANCE
SCATTERING
SODIUM COMPOUNDS
SODIUM SULFIDES
STRUCTURAL CHEMICAL ANALYSIS
SULFIDES
SULFUR COMPOUNDS
SYNTHESIS
THIOLS
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES
X-RAY DIFFRACTION
YEARS LIVING RADIOISOT