Oskar Glemser

Isopolymolybdates and Isopolytungstates

Publisher Summary The chemistry of isopolymolybdates and isopolytungstates has been an area of intense activity for several decades. Yet, even today one cannot claim that all the important processes occurring on acidification of a molybdate or tungstate solution have been elucidated. Numerous contradictory reports appearing in the literature right up to the present have repeatedly done more to confuse than to clarify the subject. Thus, it is hardly surprising that not a single textbook correctly describes the situation in acidified molybdate and tungstate solutions. The number of proposals for polyions occurring in such solutions is legion. With little exaggeration it may be said that there is no conceivable species that has not been proposed at some time or other. Much of the effort involved in this field consists in scrutinizing the experimental conditions, the evaluation of measurements, and the interpretations given in past and present publications. The large number of methods already used in these studies presents a further difficulty.

Sulfur-Nitrogen-Fluorine Compounds

Publisher Summary Since the preparation of the first pure sulphur-nitrogen-fluorine compounds, NSF, NSF and S4N4F4, in 1955 this field has developed very rapidly. The chemistry of these compounds has been the subject of several reviews, and has also been covered more or less fully in reviews on sulphur-fluorine and sulphur-nitrogen chemistry . The spate of recent publications has, however, rendered these earlier summaries incomplete. The present article covers developments up to the middle of 1970, with main emphasis on the recent work. Compounds with other halogens are considered only insofar, as they are of interest in this context. The earlier division into acyclic and cyclic compounds has been retained, as has been the classification in terms of the various oxidation numbers of sulphur. An attempt has been made starting from NSF and NSF, to point out the general relationships in the chemistry of sulphur-nitrogen-fluorine compounds.

Infra-red spectrum, structure, force constants, mean amplitudes of vibration, thermodynamic functions and molecular polarizability of NSCl

Abstract The infra-red spectrum of NSCl was studied from 300 to 4000 cm −1 . The two fundamentals v 1 and v 2 were directly observed and the third one v 3 was calculated from the overtone and combination bands. It was confirmed that NSCl has the structure NSCl with C s -symmetry and not SNCl. Force constants, mean amplitudes of vibration, molar thermo-dynamic functions and molecular polarizability were computed and the results briefly discussed.

A CNDO/2 approach to electron delocalization in N4S4 and N4S4F4

Abstract The electronic structure of N 4 S 4 and N 4 S 4 F 4 molecules is investigated within the framework of the CNDO/2 approximation. A pure alternated system is obtained for the fluorinated compound with respect to the Wiberg bond populations. On the other hand, the N 4 S 4 molecule appears to be composed of three highly delocalized “islands”, as defined by Dewar in the case of cyclophosphazenes. The “tub form” of N 4 S 4 is due to a strong spatial interaction between non-bonded sulphur atoms and, for this reason, the N 4 S 4 molecule may be called the “inorganic cyclooctatetraene”.

Vibrational studies of (n-trimethylsilylimido)sulfur compounds

Abstract The IR and Raman spectra of three compounds containing the NSN system are reported and assigned to vibrational modes by means of symmetry considerations and comparison to similar compounds. Possible molecular structures are discussed for F 2 S[NSi(CH 3 ) 3 ] 2 and S[NSi(CH 3 ) 3 ]2, the structures of which have not yet been determined, and the most probable structures (point group C 2 ) are derived by analysis of the vibrational spectra. The internal force constants are calculated for S[NSi(CH 3 ) 3 ] 3 , F 2 S[NSi(CH 3 ) 3 ] 2 , and S[NSi(CH 3 ) 3 ] 2 , and compared to the values of molecules already studied.

Molecular constants for NSCl and NSF

Abstract The complete infrared spectrum of gaseous NSCl, including the hitherto unobserved ν 3 , is reported. A set of force constants for gaseous NSCl consistent with a number of pieces of independent data such as the isotopic shifts ( 14 N 32 S 35 Cl, 15 N 32 S 35 Cl, 14 N 32 S 37 Cl, 15 N 32 S 37 Cl, 14 N 34 S 35 Cl and 15 N 34 S 35 Cl), centrifugal distortion constants ( 14 N 32 S 35 Cl), and the inertia defect ( 14 N 32 S 35 Cl) has been computed. Also, the force field of NSF has been redetermined using the vibrational frequencies and the centrifugal distortion constants.

Schwingungsspektren und Kraftkonstanten des Tetraselenomolybdats(VI) und des Tetraselenowolframats(VI). Raman-Spektren von (NH4)2MoO2S2 und (NH4)2WO2S2

Abstract Infrared and Laser Raman spectra of MoSe 4 2− (colour: deep violet) and WSe 4 2− (deep red) were recorded. The results of a normal co-ordinate analysis on these ions is given. Furthermore, the unknown Raman spectra of (NH 4 ) 2 MoO 2 S 2 and (NH 4 ) 2 WO 2 S 2 a more complete Raman spectrum of (NH 4 ) 2 MoS 4 than those previously recorded are reported and discussed.

The oxidation of perhaloalkyl-sulphurdifluoride-imides by oxygen difluoride

Abstract Perhaloalkyl Sulphuroxidifluoride imides R NSOF 2 (R = CF 3 -, C 2 F 5 -, i-C 3 F 7 -, CF 2 Cl-, CF 2 Br-CF 2 -) are isolated in high yield from the photochemical reaction of OF 2 with the appropriate difluoride-imides. In all these reactions the difluoride-diimides RNSF 2 NR are found as by-products.

Zur colorimetrischen Bestimmung des Magnesiums mit Titangelb

ZusammenfassungDie colorimetrische Bestimmung des Magnesiums mit Titangelb unter Verwendung von Polyvinylalkohol als Schutzkolloid wird angegeben. Mit Polyvinylalkohol ist es möglich, bis 20 mg Mg/100 ml in kolloider Lösung zu halten.Es werden der Einfluß der Alkalität, des Calciumgehaltes, der Titangelbmenge, die Beständigkeit der Farblösung, die Reproduzierbarkeit der Werte und der Einfluß von Stör-Ionen studiert.Röntgen- und elektronenmikroskopische Aufnahmen beweisen, daß Titangelb an Mg(OH)2 adsorbiert wird.

Die colorimetrische Bestimmung von Titan mit Sulfosalicylsure

ZusammenfassungEs werden die günstigsten Bedingungen der Farbreaktion von Titan-(IV)-salzen mit Sulfosalicylsäure für qualitative und quantitative Bestimmungen ermittelt.Die Reaktion ist gut reproduzierbar, hochempfindlich und gestattet die Bestimmung von Titan neben Eisen, Mangan, Calcium, Magnesium, Aluminium, Kupfer, Vanadin und Zink.