Articles you may be interested inVibrational energy relaxation of diatomic molecules isolated in raregas matrices: Role of orientational motions J. Chem. Phys. 68, 4056 (1978); 10.1063/1.436307 ESR of the triplet molecules CCO and CNN in raregas matrices; isotope and matrix effects J. Chem. Phys. 62, 4592 (1975); 10.1063/1.430432Nonradiative vibrational relaxation of diatomic molecules isolated in solid rare-gas matrices Mn, and Mn, have been isolated in argon, krypton, and xenon matrices and their X -band ESR spectra observed at 4 and up to 70 K, depending upon the matrix. As predicted by Nesbet, the lowest state of Mn, is I.I, and the two atoms are exchange coupled (antiferromagnetically). The temperature behavior of the ESR bands in the higher spin states (S = 1,2,3) was approximately in accord with a Lande interval rule, and a value of J = -9 ± 3 em -I was obtained from the S = 2 intensity variations. Each fine structure line appears with a superimposed II-line hyperfine pattern with splitting one-half that of isolated HMn atoms (30 G). The anisotropic exchange interactions fit the Judd-Owen relationship with D, = -0.043(2) and D. = -0.001(4) em-I. Assuming D, arises solely from magnetic dipole interaction, the interatomic distance in Mn, is calculated to be 3.4 A. Mn, appears in more concentrated matrices as a highly oriented axial molecule with its axis perpendicular to the flat sapphire substrate surface. The observed fine structure indicates that the molecule contains 25 unpaired electrons (S = 25/2) and has magnetic parametersg, = 1.997(1), gil = 1.979(2), D = -0.013(1) em-I. All HMn hyperfine structure lies within the Iinewidths and is therefore unresolved. It was concluded that the molecule most probably contains five Mn atoms and is a plane pentagon. With this model an attempt was made to rationalize the observed g shifts.190

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ESR measurements are reported for Mn2 in kypton and xenon matrices at 4 °K.(AIP)

Normal adult male mice of various strains excreted 0.6–3.1 mg of urinary protein N/day; females, considerably less. Electrophoretic measurements showed the protein to consist of three components, all having negative mobilities (–7.5 to –8.3 cm2/volt/sec x 10–5 at ph 8.5) greater than that of mouse serum albumin (–6.3 ± 0.1 cm2/ volt/sec. x 10–5 at ph 8.5). The most negative, amounting to approximately 32% of the total urinary protein, had an isoelectric ph of 4.3; the least negative, 4.5. During ultracentrifugation the urinary protein sedimented as a monodisperse system with a sedimentation coefficient of 2.28 S and a weight—average molecular weight of 17,800. Electrophoresis of mouse serum revealed a small fast-moving component which may be identical with the urinary protein.

Chromium metal, natural and isotopically enriched in 53Cr (I=3/2), was vaporized and trapped in solid neon, argon, and krypton at 4 K. An extensive ESR spectrum of 16 lines between 200 and 7000 G in neon and argon matrices was found to be due to an axial molecule with S=3, ‖D‖=0.110 cm−1, g⊥=1.9970, g∥=1.9996. 53Cr spectra showed essentially isotropic hyperfine interaction of the six unpaired spins with apparently only one nucleus and an accompanying electric field gradient at that nucleus. It is concluded that the molecule is a trigonally distorted tetrahedral Cr4 or possibly a square-based pyramidal Cr5. The unique apical atom is bonded relatively weakly to the ‘‘base’’ and is the locus of almost all of the s character among the unpaired spins. In argon and krypton matrices, another species with S=3 is observed near g=2.0 but with only a small zero-field splitting (‖D‖=0.0049 cm−1, g∥=2.005, g⊥=2.0015 in argon). The possibilities of it being a weakly perturbed Cr atom in an asymmetrical matrix site or a Crn molecule, where n(≥3) is the number of equivalent atoms, are discussed.