Spectroscopic studies on polymeric cobalt(II) and nickel(II) complexes with bridging succinonitrile and succinonitrile isotopomer ligands.

A series of cobalt(II) and nickel(II) complexes were synthesized using succinonitrile and its [1,4-13C2], [15N2]-, [2,2,3,3-2H4]- and [1,4-13C,-2,2,3,3-2H4]- isotopomers as bridging ligands. Spectroscopic studies, as well as X-ray powder diffraction profiles, were used to identify the nature of the octahedral coordination sphere of the central metal ions and to assign the vibrational spectra in full detail. The succinonitrile ligands were found to be in trans configuration in all the complexes studied and to be coordinated via the lone pairs of their nitrile nitrogens. The rule of mutual exclusion was found to be fulfilled for the succinonitrile ligands under the Ci symmetry of the complexes and the vibrations of the succinonitrile ligands were found to appear in either the infrared or the Raman spectra. All succinonitrile isotopomers exhibited blue-shifts of 43-71 cm(-1) upon coordination, while most of the other vibrations remained unchanged or underwent small shifts of only a few wavenumbers. The mass differences of the succinonitrile isotopomers were found to shift mainly the vibrations of the respective affected part of the molecules in comparison with the normal succinonitrile. The exchange of the halides, which are coordinated to the central metal ion, was also found to influence the vibrations of the associated water molecules and we could identify vibrational bands arising due to the H-bond interaction between the halides and the water molecules. Finally, we showed that all complexes under consideration have, spectroscopically, the same symmetry.

Vibrational spectra of succinonitrile and its [1,4-13C2]-,[2,2,3,3,-2H4]- and 1,4-13C-2,2,3,3-2H4]-isotopomers and a force field of succinonitrile.

[1,4-13C2]-succinonitrile, [2,2,3,3-2H4]-succinonitrile, [1,4-13C2-2,2,3,3-2H4]-succinonitrile have been synthesized and, for the first time, the infrared and Raman spectra of these succinonitrile isotopomers have been discussed in detail. The spectra were recorded at ambient temperature and at the temperature of liquid nitrogen and assignments of the vibrational bands of all above isotopomers have been made. In addition to this, the force field of succinonitrile in its two configurations, gauche and trans, have been calculated using all experimental frequencies and the ab-initio method. Also, the assignments of the vibrational bands of the 'normal' succinonitrile molecule have been achieved using the results of the force field calculations to support the assignments for the normal succinonitrile, as well as for the isotopomers.

Crystal structures at megabar pressures determined by use of the cornell synchrotron source.

X-ray diffraction studies have been carried out on alkali halide samples 10 micrometers in diameter (volume 10(-9) cubic centimeter) subjected to megabar pressures in the diamond anvil cell. Energy-dispersive techniques and a synchrotron source were used. These measurements can be used to detect crystallographic phase transitions. Cesium iodide was subjected to pressures of 95 gigapascals (fractional volume of 46 percent) and rubidium iodide to pressures of 89 gigapascals (fractional volume of 39 percent). Cesium iodide showed a transformation from the cubic B2 phase (cesium chloride structure) to a tetragonal phase and then to an orthorhombic phase, which was stable to 95 gigapascals. Rubidium iodide showed only a transition from the low-pressure cubic B1 phase (sodium chloride structure) to the B2 phase, which was stable up to 89 gigapascals.

Evaluation of complicating osteomyelitis with Tc-99m MDP, In-111 granulocytes, and Ga-67 citrate.

Studies with gallium-67 and three-phase bone imaging (TPBS), though very sensitive, are not very specific in evaluating suspected osteomyelitis (OM) that is superimposed upon other diseases causing increased bone turnover. A total of 57 patients with suspected OM were studied; this included 48 with increased bone turnover. All of the patients were studied with granulocytes labeled with In-111 acetylacetone (In-111 GRAN), TPBS and 29 of these patients had Ga-67 studies as well. In-111 GRAN had a sensitivity of 100% in acute OM and 60% in chronic OM, with a specificity of 96%. Gallium-67 was excellent in ruling out OM when the study was normal, or in ruling in OM when the relative uptake of Ga-67 exceeded the uptake of Tc-99m MDP, or when the Ga-67 in bone had a different distribution from the TPBS. Unfortunately, these criteria were met in only 28% of our subjects. We conclude that when added to TPBS, the In-111 GRAN study plays an important role in detecting complicating OM.

Preparation of micron thick specimens for high pressure study.

The electrical resistance behavior of a material under very high pressure can be studied by pressing the material with a diamond indentor against a diamond flat. The high pressures generated can be calculated using Hertz's theory provided the material thickness is about a micron or less. Here we describe a method of preparing micron thick specimens of a few millimeters in size. We have prepared micron thick specimens of a few millimeters in size of Si (100), Si (111), NaCl (100). The result of high pressure study on Si (100) is also presented.

High pressures on small areas.

Small diamond indentors with spherical tips were pressed against a polished diamond flat. Pressures were calculated from Hertz contact theory. Very high pressures were achieved on small areas.