Publications by authors named "Urban Frey"

An overview of international relations at the Universities of Applied Sciences in Switzerland is presented.

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An overview of international relations at the Universities of Applied Sciences in Switzerland is presented.

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Making use of a convenient synthetic approach to prepare the deuterated S-3-(hexan-1-ol)-cysteine by a Michael addition reaction, an analytical method was developed to measure the presence of the cysteine S-conjugate, precursor of 3-sulfanylhexan-1-ol (3-mercaptohexan-1-ol), in must and wine from Petite Arvine vine. The method uses a stable isotope dilution assay with a suitable one-step sample preparation and HPLC-MS detection. The method has limits of detection and quantification of 3 and 10 microg/L, respectively.

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The C(2)-symmetric electron-poor ligand (R)-BINOP-F (4) was prepared by reaction of (R)-BINOL with bis(pentafluorophenyl)-phosphorus bromide in the presence of triethylamine. The iodo complex [CpRu((R)-BINOP-F)(I)] ((R)-6) was obtained by substitution of two carbonyl ligands by (R)-4 in the in situ-prepared [CpRu(CO)(2)H] complex followed by reaction with iodoform. Complex 6 was reacted with [Ag(SbF(6))] in acetone to yield [CpRu((R)-BINOP-F)(acetone)][SbF(6)] ((R)-7).

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The water exchange process on [(CO)(3)Re(H(2)O)(3)](+) (1) was kinetically investigated by (17)O NMR. The acidity dependence of the observed rate constant k(obs) was analyzed with a two pathways model in which k(ex) (k(ex)(298) = (6.3 +/- 0.

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Solvent exchange on the half-sandwich organic solvates [(eta(5)-C(5)Me(5))M(S)(3)](2+) (M = Rh, S = MeCN (1) or Me(2)SO (3); and M = Ir, S = MeCN (2) or Me(2)SO (4)) has been investigated as a function of temperature, pressure, and concentration of free solvent by (1)H NMR line-broadening techniques in CD(3)CN and/or CD(3)NO(2). The exchange rates span several orders of magnitude, from k(ex)(298) = 8.8 x 10(-)(2) s(-)(1) for 2 to 3.

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Solvent exchange on trans-[Os(en)(2)(eta(2)-H(2))S](2+) (S = H(2)O, CH(3)CN) has been studied in neat solvent as a function of temperature and pressure by (17)O NMR line-broadening and isotopic labeling experiments (S = H(2)O) and by (1)H NMR isotopic labeling experiments (S = CH(3)CN). Rate constants and activation parameters are as follows for S = H(2)O and CH(3)CN, respectively: k(ex)(298) = 1.59 +/- 0.

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