Molecular structure, spectroscopy and matrix photochemistry of fluorocarbonyl iodide, FC(O)I.

The molecular structure of FC(O)I has been determined by gas electron diffraction. High-level ab initio methods, including coupled-cluster and the new correlation-consistent basis sets for fourth row elements, have been used to calculate the structure of FC(O)I. A comprehensive vibrational spectroscopic study (both IR and Raman) complemented by high-level calculations has also been performed. Furthermore, UV, mass, and NMR spectra have been recorded for FC(O)I. The matrix photochemistry of FC(O)I has been studied with a low-pressure mercury lamp and with a high-pressure xenon lamp in combination with interference and cut-off filters. UV photolysis revealed the formation of the OC. IF and OC.FI complexes and further photolysis of these complexes at lambda>320 nm resulted in a re-formation of FC(O)I. The structural conformation of the complexes has been characterized by comparing shifts in their CO and IF vibrational modes with respect to those of the free species. The structures, vibrational properties, and stability of the complexes were analyzed with the aid of coupled-cluster ab initio calculations.

IR and UV spectra of the matrix-isolated peroxy radicals CF3OO, trans-FC(O)OO, and cis-FC(O)OO

The peroxy radicals CF3OO and FC(O)OO are prepared in high yields by vacuum flash pyrolysis of ROONO2 or ROOOR (R=CF3, FC(O)), highly diluted in inert gases, and subsequent isolation in inert-gas matrices by quenching the product mixtures at low temperatures. The IR spectrum of FC(O)OO was observed for the first time and eight fundamentals as well as several combinations were measured and assigned for both cis and trans rotamers of FC(O)OO. Discrepancies in an earlier assignment of the fundamentals of CF3OO have been eliminated and its IR spectrum is reported fully. The matrix UV spectra of both peroxy radicals (X2A"--> 2(2)A" transition) are in agreement with the gas-phase spectra; however, there are differences in the absorption cross-sections, for which possible reasons are discussed. The X2A"--> 1(2)A' transitions in the near IR region are too weak to be detected with our instrumentation.

Diagnosis and therapy of liver abscess by ultrasonographic imaging, puncture and drainage.

Liver abscesses in 19 patients were primarily diagnosed by real-time ultrasound. Characteristic features and changes in the course of disease are described. Fine needle puncture under ultrasonographic guidance confirmed the diagnosis and permitted bacteriologic examination. Ultrasonographically guided abscess drainage dramatically improved the clinical condition, and can be recommended as an alternative to surgical drainage.

[The Mirizzi syndrome as a cause of obstructive jaundice--its demonstration by sonography and PTC (author's transl)]. / Das Mirizzisyndrom als Ursache des Verschlussikterus--Darstellung durch Sonographie und PTC.

Two patients with the Mirizzi syndrome are described and the findings on sonography and PTC care discussed. The difficulties of differentiating this from biliary obstruction due to tumour are stressed and treatment and prognosis are set out.

[Sonographic differentiation of pulmonary opacities (author's transl)]. / Sonographische Differenzierung pulmonaler Verschattungen.

Sonography offers a supplementary diagnostic method in cases where X-ray examination has established the presence of opacities in the lungs. Simple criteria generally allow differentiation between solid and liquid structures and thus to distinguish between effusions, haematoma, empyema and adhesions and tumors. - Sonographically directed needle biopsies following the sonographic localization of encysted effusions or a tumor ensure the correct site of puncture and provide the means to establish the diagnosis histologically, cytologically and bacteriologically.