Mass spectrometric studies of organophosphorus compounds: III—Remarkable migration of chalcogen on electron impact of organophosphorus compounds

The mass spectra of several dibenzo (d.f)-1,3,2,-dioxaphosphorepines of the type where X=0, S, Se and R=2,2′-biphenylylene, have been studied. Dibenzochalcogen ions [RX]⁺˙ stemming directly from [M]⁺˙ were observed with high intensities, indicating specific migration of X from phosphorus to carbon with simultaneous destruction of the dioxaphosphorepine ring. Simple cleavage of P? Y as usually observed in similar organophosphorus compounds is not a common process here.     

Über die Uranylverbindungen des Natrium-cyklohexyldithiocarbaminats

Zusammenfassung Na-cyklohexyldithiocarbaminat reagiert im p_H-Bereich 6,6 bis 7,2 mit Uranylsalzen unter Bildung eines in Wasser mit gelber Farbe lösliehen Komplexes, der bei p_H 6,6 ein Absorptionsmaximum bei 392 bis 394 nm besitzt. Die wäßrige Lösung wird durch Zusatz von Alkalilauge bis zum p_H 8 bis 9 momentan entfärbt.Es wird ein Kaliumdoppelsalz KUO₂(S₂HCNC₆H₁₁)₃ · 3 H₂O beschrieben; ferner wird über die Umwandlung des Calciumdoppelsalzes beim Kochen mit NaOH berichtet.

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Summary Sodium cyolohexyldithiooarbamate reacts, in the p_H range 6.6 to 7.2, with uranium salts to yield a complex which gives a yellow aqueous solution. The absorption maximum is at 392–394 nm at p_H 6.6. The aqueous solution loses its color immediately when caustic alkali is added to raise the p_H to 8 or 9.A potassium double salt, KUO₂(S₂HCNC₆H₁₁)₃ · 3 H₂O is described. A report is also given of the transformation of the calcium double salt on boiling with NaOH.

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Résumé Le dithiocarbamate de cyclohexylsodium réagit dans le domaine de p_H 6,6 à 7,2 sur les sels d'uranyle avec formation d'un complexe coloré en jaune, soluble dans l'eau, qui possède à p_H 6,6 un maximum d'absorption pour 392–394 nm. Par addition de lessive alcaline jusqu'à p_H 8 à 9 on décolore momentanément la solution aqueuse.On décrit un sel double de potassium KUO₂(S₂HCNC₆H₁₁)₃ · 3 H₂O; on rend compte, de plus, de la transposition du sel double de calcium par chauffage avec la soude.

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Gewidmet zur 100. Wiederkehr des Geburtstages vonFriedrich Emich.     

Über magnetische Beeinflussung der Polarisation der Resonanzfluoreszenz

1. Historical remarks concerning magnetic influence on the polarization of resonance fluorescence and its explanation as the Zeeman effect. 2. Rotation of the plane of polarization of the resonance fluorescence of Hg by weak magnetic fields and determination of the lifetime of the excited state. 3. Experiments concerning the excitation of the resonance fluorescence of Hg by light with different kinds and directions of polarization.     

Separation of rotational diffusion and level kinetics in transient absorption spectroscopy

Transient absorption spectroscopy on electronic levels of molecules in the liquid phase is governed by population kinetics as well as rotational diffusion. The goal of transient absorption experiments has been the true level kinetics free of rotation. Moreover, to extract the rotational time from transient photodichroism experiments the knowledge of true population kinetics is instrumental. Three methods for separating rotational and level kinetics are described theoretically, and one of them is performed experimentally using a repetitive picosecond spectrometer for the measurement of rotational behaviour of fluorescein 27 in solvents of different viscosity.     

电解池电阻和容抗的快速测定仪

利用锁定放大器, 恒电势仪, 压控频率正弦波信号发生器等组装成电解池电阻和容抗的快速测定仪。可以快速地自动测是和绘出阻抗谱图和电阻/容抗～时间图。采用微小恒定振幅正弛交流电流(<10 μA)作为微扰, 数据可能较为可靠。给出了线路及所需滤波器元件的数据, 说明仪器各部份之间的干扰可以减少。测定了滴汞电极在1 mol L~(-1)Na_2SO_4溶液中及1 mol L~(-1)Na_2SO_4被正庚醇饱和的溶液中的微分电容～电势数值。证明仪器工作良好。另外, 从实验数据和理论分析, 均表明D.C.Grahame的被广泛引用的有关经典数据有误。本文做了修正。还测定了半导体氧化铁电极在光照下黑暗中的阻抗谱图和氧化银电极充电和停止充电后开路下的电阻～时间图, 显示了仪器在电化学研究中利用的可能性。     

Classification of signatures of Bovine Spongiform Encephalopathy in serum using infrared spectroscopy

Signatures of Bovine Spongiform Encephalopathy (BSE) have been identified in serum by means of "Diagnostic Pattern Recognition (DPR)". For DPR-analysis, mid-infrared spectroscopy of dried films of 641 serum samples was performed using disposable silicon sample carriers and a semi-automated DPR research system operating at room temperature. The combination of four mathematical classification approaches (principal component analysis plus linear discriminant analysis, robust linear discriminant analysis, artificial neural network, support vector machine) allowed for a reliable assignment of spectra to the class "BSE-positive" or "BSE-negative". An independent, blinded validation study was carried out on a second DPR research system at the Veterinary Laboratory Agency, Weybridge, UK. Out of 84 serum samples originating from terminally-ill, BSE-positive cattle, 78 were classified correctly. Similarly, 73 out of 76 BSE-negative samples were correctly identified by DPR such that, numerically, an accuracy of 94.4 % can be calculated. At a confidence level of 0.95 (alpha = 0.05) these results correspond to a sensitivity > 85% and a specificity > 90%. Identical class assignment by all four classifiers occurred in 75% of the cases while ambiguous results were obtained in only 8 of the 160 cases. With an area under the ROC (receiver operating charateristics) curve of 0.991, DPR may potentially supply a valuable surrogate marker for BSE even in cases in which a deliberate bias towards improved sensitivity or specificity is desired. To the best of our knowledge, DPR is the first and--up to now--only method which has demonstrated its capability of detecting BSE-related signatures in serum.     

Influence of structural changes on the ion selectivities of magnesium ionophores based on malonic acid diamides

In an investigation of octamethylene bis(malonic acid diamides) and their selectivities for magnesium, it was found that presence of secondary amides within the particular ionophore played a considerable role in the enhancement of magnesium selectivity. Similar effects in other ionophores, i.e. tris(malonic acid diamides), were thus systematically looked at with the help of selectivity measurements with the hope of optimizing the number of secondary and tertiary amides so as to improve the magnesium selectivity. The syntheses of several investigated tris(malonic acid diamide) isologues are equally reported.Deceased in November 1992     

The mass spectra of TMS-ethers of deuterated polyalcohols. A contribution to the structural investigation of sugars

Aldoses, ketoses, deoxy-aldoses, deoxy-keto-aldoses, lactones, deoxy-lactones and other similar compounds are readily reduced by NaBD₄ to the corresponding polyalcohol. Their trimethylsilyl ethers show characteristic mass spectra which allow firm assignments of the position of deuteration and hence of the nature of the starting sugar compound. The g.c./m.s. coupling technique even allows trace analysis since full information can be derived from the most intense fragments of the mass spectra.