Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 364 (1999), S. 22-27 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The working mechanism of the differential CO2 sensor inherently contains several calibration problems. These difficulties are highlighted and some possibilities for eliminating them are discussed. Finally, a simple error analysis is shown for optimizing the composition of the standard solutions to be used for the calibration of the differential CO2 probe in blood electrolyte analyzers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 363 (1999), S. 607-611 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Three topics are summarized: advances in potentiometric sensors, in optical sensors, and in enzyme-based and enzyme-sensing biosensors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 13 (1994), S. 849-851 
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1619-1619 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: High molecular weight poly(vinyl chloride) and aliphatic polyurethane (Tecoflex)-based ion selective membranes, with normal and reduced amounts of plasticizer, as well as without plasticizer, were tested with respect to their analytical properties, their biocompatibility, and cellular responses. The analytical properties of the membranes did not change significantly within a wide range of polymer to plasticizer rations. However, the membranes with reduced plasticizer content had better adhesive properties, less anion interference, extended life time, and better biocompatibility. Using the cage implant system, the results showed that an increase of plasticizer weight percent in Tecoflex membranes correlated positively with the increase in host inflammatory response up to 14 days of implantation. The results also demonstrated that both PVC and Tecoflex-based ion-selective membranes with the most common membrane composition (1:2 polymer to plasticizer ratio) exhibited a similar acute inflammatory response, but the PVC-based membrane elicited a reduced chronic inflammatory response when compared with the Tecoflex-based membrane. © 1994 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0044-2313
    Keywords: Ether-phosphanes ; palladium complexes ; polysiloxane matrices ; crystal structure ; CP MAS NMR spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Supported Organometallic Complexes. IV. Structural Investigations on Neutral and Cationic (Ether-phosphane)palladium(II) Complexes.Reaction of the (ether-phosphane) ligands PhP(R)CH2 - D (2a-c) [D=CH2OCH3: R=Ph (a), (CH2)3Si(OCH3)3 (b), (CH2)3SiO3/2 (b′); D= R=(CH2)3Si(OCH3)3 (c), (CH2)3SiO3/2 (c′)] with Cl2Pd(COD) (1) results in the formation of Cl2Pd(P  -  O)2 (3a-c). Cleavage of Cl- from 3 with AgSbF6 yields the cationic, monochelated complexes [ClPd(P  -  O)(P ∩ O)]+ (4 a - c) (P  -  O: η1-P-coordinated; P ∩ O: η2-O ∩ P-coordinated). 4 a crystallizes in the monoclinic space group P21/c with the lattice constants a=1 062,4(2), b=1 912,2(4) und c=1 635,5(3) pm, β=101,22(3)° and Z=4 (R=0,0341; Rw=0,033). With water 3 b, c and 4 b, c are subjected to polycondensation to give the supported complexes 3 b′, c′, 4 b′, c′. The structure 3 b′, c′, 4 b′, c′ is investigated by comparison of their 31P CP MAS data with the 31P{1H} NMR spectra of their soluble precursors 3 b, c, 4 b, c. 13C CP MAS NMR spectra of 3 b′, c′ and 4 b′, c′ indicate η1-P- and η2-O ∩ P-coordination of the ligands. The polysiloxane network of 4 b′ was inspected by contact time variation of the 29Si CP MAS NMR spectra and it appeared that 77% of the Si - O units are crosslinked, corresponding to a ratio T4:T3:T1=67:100:10.
    Notes: Die Reaktion der (Ether-Phosphan)-Liganden PhP(R)CH2 - D (2a - c) [D=CH2OCH3: R=Ph (a), (CH2)3Si(OCH3)3 (b), (CH2)3SiO3/2 (b′); D= R=(CH2)3Si(OCH3)3 (c), (CH2)3SiO3/2 (c′)] mit Cl2Pd(COD) (1) liefert die Komplexe Cl2Pd(P ∼ O)2 (3a - c). Durch Chloridabspaltung aus 3 a - c entstehen die kationischen Monochelaktomplexe [ClPd(P ∩O)(P ∼ O )]+ (4 a - c) (P ∼ O: η1-P-koordiniert; P ∩ O: η2-O ∩ P-koordiniert). 4a kristallisiert in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a=1 062,4(2), b=1 912,2(4) und c=1 635,5(3) pm, β=101,22(3)° und Z=4 (R=0,0341; Rw=0,033). 3 b, c und 4 b, c polykondensieren mit Wasser zu den trägerfixierten Komplexen 3 b′, c′, 4b′, c′. Die Bestimmung der Strukturen von 3 b′, c′, 4 b′, c′ erfolgt durch Vergleich der 31P-CP-MAS-NMR- mit den 31P{1H}-NMR-Spektren der löslichen Komplexe 3 b, c, 4 b, c. Aus den 13C-CP-MAS-NMR-Spektren von 4 b′, c′ ergibt sich die η1-P- und η2-O ∩ P-Koordination der Liganden. Eine Kontaktzeitvariation der 29Si-CP-MAS-NMR-Spektren von 4 b′ zeigt, daß die Matrix zu 77% vernetzt ist (T4:T3:T1=67:100:10).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0044-2313
    Keywords: (Ether-phosphine)ruthenium(II) complexes ; polysiloxane ; supported complexes ; preparation ; 31P and 29Si CP-MAS-NMR spectroscopy ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Properties of Soluble and Polysiloxane-Supported (Ether-Phosphine)ruthenium(II) ComplexesPhosphine-modified Polysiloxanes of the type x SiO2 · [SiO3/2(CH2)6P(Ph)R] (x = 0 - 3, I-IV) were prepared by hydrolytic condensation of (MeO)3Si(CH2)6P(Ph)R [1; R = CH2CH2OMe (a), CH2C4H7O (b), CH2C4H7O2 (c), Ph (d)]. Crosslinking was achieved by cocondensation of 1 and Si(OEt)4.2 SiO2 · [SiO3/2(CH2)6P(Ph)CH2CH2OMe] (IIIa) was investigated by means of 31P and 29Si CP-MAS-NMR-spectroscopy, especially in view of a quantification of silyl species which revealed the following ratios: T2:T4:Q2:Q3:Q4 = 76:158:48:135:82. Reaction of RuCl2(PPh3)3 with 3 moles of 1a gave fluxional RuCl2(P∩O)(P∼O)2 (4a). From its temperature dependent 31P{1H}-NMR spectrum the temperatures of coalescence and the corresponding activation enthalpies could be estimated at -25°C (46 kJ · mol-1) and +20°C (55 kJ · mol-1). Soluble 1a-d as well as their insoluble counterparts I-IV were treated with [RuCl2(CO)2]n to give all-trans-RuCl2(CO)2(PR3)2 (6). On heating (120°C) 6 could be transformed into isomeric cis, cis, trans-RuCl2(CO)2(PR3)2 (7). Decarbonylation occurred on irradiation of 6. Polysiloxane-supported ruthenium complexes were proved to be active in the heterogeneous hydrogenation of crotonaldehyde. Thus, at p(H2) = 50 bat, T = 120°C, reaction time = 190 min, and at a molar ratio of aldehyde: Ru = 250:1, all-trans-RuCl2(CO)2(P∼O)2 (6f, O,P = IIIa) effected a conversion of 50%, crotyl alcohol being formed in comparatively high selectivities. Moreover, no loss of metal or ligand from the support could be observed.
    Notes: Durch Kondensation von (MeO)3Si(CH2)6P(Ph)R [1; R = CH2CH2OMe (a), CH2C4H7O (b), CH2C4H7O2 (c), Ph (d)] bzw. durch dessen Cokondensation mit Si(OEt)4 gelang der Zugang zu Phosphan-modifizierten Polysiloxanen des Typs x SiO2 · [SiO3/2(CH2)6P(Ph)R] (x = 0 - 3, I-IV).2 SiO2 · [SiO3/2(CH2)6P(Ph)CH2CH2OMe] (IIIa) wurde mit Hilfe der 31P- und 29Si-CP-MAS-NMR-Spektroskopie untersucht. Die Quantifizierung der Silylspezies durch Kontaktzeitvariation ergab ein Verhältnis von T2:T4:Q2:Q3:Q4 = 76:158:48:135:82. Durch Umsetzung von RuCl2(PPh3)3 mit 1a (1:3) entstand RuCl2(P∩O)(P∼O)2 (4a), dessen flukturierendes Verhalten durch die Temperaturabhängigkeit des 31P{1H}-NMR-Spektrums nachgewiesen wurde. Die Koaleszenztemperaturen sowie die Freien Aktivierungsenthalpien der Austauschprozesse wurden zu-25°C (46 kJ · mol-1) und + 20°C (55 kJ · mol-1) bestimmt. 1a-d sowie ihre unlöslichen Analoga I-IV reagierten mit [RuCl2(CO)2]n zu Komplexen des Typs all-trans- RuCl2(CO)2(PR3)2 (6), die sich thermisch (120°C) zu cis,cis,trans-RuCl2(CO)2(PR3)2 (7) isomerisieren sowie photochemisch decarbonylieren ließen. Im Rahmen von Hydrierungsversuchen von Crotonaldehyd wurden Polysiloxan-gebundene Rutheniumkomplexe als Präkatalysatoren eingesetzt. Immobilisiertes all-trans-RuCl2(CO)2(P∩O)2 (6f; O,P = IIIa) ergab bei p(H2) = 50 bar, T = 120°C und 0,4 Molprozent Ru bezogen auf Crotonaldehyd nach 190 min einen Hydrierungsgrad von 50% bei einem Molverhältnis Crotylalkohol: Butyraldehyd von über 1:1. Auch nach viermaliger Wiederverwendung des Katalysators konnte kein Ligand-bzw. Rutheniumverlust durch „leaching“ festgestellt werden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...