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Determination of the pore widths of highly porous materials with NMR microscopy (1997)

Pauli, J. ; Scheying, G. ; Mügge, C. ; [et al.]

Springer

Fresenius' journal of analytical chemistry 357 (1997), S. 508-513

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ISSN: 1432-1130

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology

Notes: Abstract The quantitative characterization of macro-porous materials with regard to pore width and pore width distribution was accomplished for the first time by using 1H-NMR microscopy in combination with suitable methods of digital image analysis. Here we present the newly developed algorithm and discuss the first experimental results. Large-pored glass filter systems filled with silicon oil as intrusion fluid were used as references. Silicates of unknown pore width were analyzed both with the new method and with Hg intrusion. NMR image data were recorded using a 3D spin echo sequence, which gave 128 slice images with a spatial resolution of 14.5 μm × 14.5 μm within each slice, with a slice-thickness of 37 μm or 48 μm. A quantitative evaluation of the 3D NMR data, with regard to pore width and pore width distribution, was done using the appropriate image processing function of the HORUS program. Individual slice evaluation was performed first, followed by an analysis of the binding elements between the slices. Pore widths of the glass filters determined using this analytical algorithm were in accordance with the manufacturer’s values, and silicate pore widths were in good agreement with the values determined by Hg intrusion.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s002160050203

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Fluoridolyse von N-Phosphorylphosphazenen (1995)

Riesel, L. ; Löwe, C. ; Pauli, J.

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 621 (1995), S. 865-870

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ISSN: 0044-2313

Keywords: Fluoridolysis ; N-Phosphoryl Phosphazenes ; Fluorophosphates ; Diazadiphosphetine ; Chemistry ; Inorganic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Description / Table of Contents: Fluoridolysis of N-Phosphoryl PhosphazenesIn the reaction of the N-phosphoryl phosphazenes X3P=N—P(Y)X2 (X = Cl, PhO, Et2N, CF3CH2O, PrS, Ph; Y = O, S) (1-18) with Et3N · nHF (n ≍ 3 or 0.6) fluoro derivatives of N-phosphoryl phosphazenes (see table 2) as well as N-phosphorylated imiddotetrafluorophosphates, [F4P=N—P(Y)Cl2]- (Y = O, S), and imidopentafluorophosphates, [F5P—N—P(Y)X2]2- or [F5P—NH—P(O)X2]- (see table 3), are formed. t-BuNHPCl2=N—POCl2 reacts in acetonitrile with Et3N or i-Pr2EtN to form a product, representing probably the diazadiphosphetine (5 b).

Notes: Bei der Umsetzung der N-Phosphorylphosphazene X3P=N—P(Y)X2 (X = Cl, PhO, Et2N, CF3CH2O, PrS, Ph; Y = O, S) (1-18) mit Et3N · nHF (n ≍ 3 oder 0,6) werden durch den Austausch von Chlor sowie PhO-, Et2N- und CF3CH2O-Gruppen gegen Fluor Fluorderivate von N-Phosphorylphosphazenen (siehe Tab. 2) sowie N-phosphorylierte Imiddotetra- und -pentafluorophosphate, [F4P=N—P(Y)Cl2]- (Y = O, S) und [F5P—N—P(Y)X2]2- bzw. [F5P—NH—P(O)X2]- (siehe Tab. 3) gebildet. t-BuNHPCl2=N—POCl2 reagiert in Acetonitril mit Et3N oder i-Pr2EtN zu einem Produkt, bei dem es sich höchstwahrscheinlich um das Diazadiphosphetin (5 b) handelt.

Additional Material: 5 Tab.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/zaac.19956210527

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Fluoridolyse von Diphosphorylverbindungen (1995)

Löwe, C. ; Pauli, J. ; Riesel, L.

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 621 (1995), S. 894-900

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ISSN: 0044-2313

Keywords: Fluoridolysis ; Imidodiphosphoryl Compounds ; Methanediphosphonic Acid Derivatives ; Azadiphosphetidine ; Pentafluorophosphates ; Chemistry ; Inorganic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Description / Table of Contents: Fluoridolysis of Diphosphoryl CompoundsThe behaviour of diphosphoryl compounds [X2(O)P]2Y in fluoridolysis reactions is decisively determined by the nature of the bridging group Y. In the cases of Y = NH and CH2 and X = Cl [F2P(O)]2N- and [F2P(O)]2CH2 are obtained quantitatively. For Y = NPh, O, and CH2 the formation of phosphorylated pentafluorophosphates [F5P—Y—POX2]- is observed. Amido and ester derivatives containing fluorine (see table 2) are obtained from the corresponding chloro compounds by Cl/F exchange. Fluoridolysis of the azadiphosphetidine 19 results in the formation of acyclic 19 a.

Notes: Das Fluoridolyseverhalten von Diphosphorylverbindungen [X2(O)P]2Y wird maßgeblich durch die Brückengruppe Y bestimmt. Im Falle von Y = NH und CH2 sowie X = Cl werden quantitativ [F2P(O)]2N- und [F2P(O)]2CH2 erhalten. Für Y = NPh, O und CH2 wird die Bildung von phosphorylierten Pentafluorophosphaten [F5P—Y—POX2]- beobachtet. Aus chlorhaltigen Amido- und Esterderivaten werden durch Chlor-Fluor-Austausch die entsprechenden Fluorderivate erhalten (siehe Tab. 2). Die Fluoridolyse des Azadiphosphetidins 19 ergibt die acyclische Verbindung 19 a.

Additional Material: 5 Tab.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/zaac.19956210531

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