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2.
Hans-Detlev Gilsing Jürgen Angerer Dietrich Prescher 《Monatshefte für Chemie / Chemical Monthly》2005,1(10):795-801
The synthesis of an oxidative major metabolite of bis(2-ethylhexyl) phthalate is described. The target molecule and its ring-deuterated isomer were obtained via acylation of the appropriate -hydroxy benzyl ester or the corresponding carboxylate with phthalic anhydride or phthalic anhydride-d4. All transformation steps proceed with high yields. 相似文献
3.
4.
Wolfgang?Gutleben Verena?Unterholzner Dietmar?Volgger Andreas?ZemannEmail author 《Mikrochimica acta》2004,146(2):111-117
In the course of this investigation, a method for the characterization and differentiation of paper pulps was developed. After hydrolyzation of the papers and the respective raw pulps with trifluoroacetic acid, the hydrolyzates were analyzed with respect to their carbohydrate composition using ion exchange chromatography. The variations in carbohydrate composition mainly arise from the various hemicelluloses of the papers and pulps. The chromatographic results were then further processed using principal component analysis which allows correlating the various papers to different pulp materials. 相似文献
5.
Hans-Detlev?GilsingEmail author Jürgen?Angerer Dietrich?Prescher 《Monatshefte für Chemie / Chemical Monthly》2005,136(5):795-801
Summary. The synthesis of an oxidative major metabolite of bis(2-ethylhexyl) phthalate is described. The target molecule and its ring-deuterated isomer were obtained via acylation of the appropriate -hydroxy benzyl ester or the corresponding carboxylate with phthalic anhydride or phthalic anhydride-d4. All transformation steps proceed with high yields. 相似文献
6.
The CD. spectra of carotenoids in the 220-500 nm region may by inspection be classified as (a) essentially Conservative, (b) intermediate, or (c) essentially nonconservative. A conservative spectrum shows in that spectral region a sequence of 5-6 relatively sharp Cotton effects of alternating sign, the rotatory strengths of which roughly add to zero. In a non-conservative spectrum Δ? has the same sign over the whole region and its absolute value is in general somewhat smaller. In general, typical conservative spectra invert upon isomerization of the molecule from all-trans to mono-cis. Non-conservative spectra do not invert. The model of a chiral polyene of the length of the conjugated carotene chromophore reproduces well the main features of the conservative spectra. The theoretical predictions and the experimental data are shown to conform to the C2-rule [43] [44]. The particular nature of the longest-wavelength transition is interpreted. Based on a summary of the chiroptic data on about 50 naturally occurring compounds, the question is discussed of when conservative spectra arise and when not. 相似文献
7.
Colourless single crystals of the caffeine adduct of mercurous perchlorate dihydrate, [Hg2(Caf)2](ClO4)2(H2O)2, were grown from aqueous solutions of mercurous perchlorate and caffeine by isothermal evaporation at ambient temperature. The crystal structure (monoclinic, P21/n, Z = 4, a = 1628.0(2), b = 780.4(1), c = 2229.6(3) pm, β = 99.84(1)°, R1(all data) = 0.0894) contains [trans‐Caf‐Hg‐Hg‐Caf]2+ cations with a Hg‐Hg distance of 250.88(6) pm, Hg‐N (bond) distances of 214.4(6) and 215.1(6) pm and Hg‐Hg‐N angles of 176.9(2) and 165.1(2)°, respectively. These cations are attached via weak Hg‐O contacts to dimers which are further arranged to leave large channels into which one crystal water molecule is included. The second water molecule and the two perchlorate anions are weakly attracted to one Hg atom. 相似文献
8.
Hans-Detlev Gilsing Jürgen Angerer Dietrich Prescher 《Monatshefte für Chemie / Chemical Monthly》2002,133(8):1147-1155
Summary. The synthesis of two oxidized metabolites of bis-(2-ethylhexyl)-phthalate is described. The target structures were obtained
by esterification of the appropriate alcohol carrying a protected hydroxy group with phthalic anhydride, followed by deprotection
and further oxidation.
Received February 26, 2002. Accepted March 6, 2002 相似文献
9.
Braun T Steffen A Schorlemer V Neumann B Stammler HG 《Dalton transactions (Cambridge, England : 2003)》2005,(20):3331-3336
Treatment of a toluene solution of [PdMe(2)(Cy(2)PCH(2)PCy(2))](1) with pentafluoropyridine in the presence of traces of water affords the generation of the A-frame complexes [(PdMe)(2){mu-kappa(2)(P,P)Cy(2)PCH(2)PCy(2)}(2)(mu-F)][SiMeF(4)]() and [(PdMe)(2){mu-kappa(2)(P,P)Cy(2)PCH(2)PCy(2)}(2)(mu-F)][OC(5)NF(4)](2b). If the reaction is performed in an NMR tube equipped with a PFA inliner, complex 2b is produced, only. Treatment of 1 with pentafluoropyridine in the presence of an excess water yields the pyridyloxy complex [PdMe(OC(5)NF(4))(Cy(2)PCH(2)PCy(2))](3). Compound [(PdMe)(2){mu-kappa(2)(P,P)Cy(2)PCH(2)PCy(2)}(2)(mu-F)][FHF](2c) bearing a bifluoride anion instead of SiMeF(4)(-) or OC(5)NF(4)(-) can be generated by reaction of 1 with substoichiometric amounts of Et(3)N.3HF. The analogous complex [(PdMe)(2){mu-kappa(2)(P,P)Ph(2)PCH(2)PPh(2)}(2)(mu-F)][FHF] (5c) has been synthesized by addition of Ph(2)PCH(2)PPh(2) to a solution of [PdMe(2)(Me(2)NCH(2)CH(2)NMe(2))](4) in THF and subsequent treatment of the reaction mixture with Et(3)N.3HF. The structure of the A-frame complex 5c has been determined by X-ray crystallography. 相似文献
10.
The carborane–siloxane copolymers Dexsil 300, a 34.5% bis(dimethylsilyl)-m-carborane–65.5% dimethylsiloxane copolymer, and Dexsil 400, a 24.9% bis(dimethylsilyl)-m-carborane–50.8% dimethyl, 24.3% methylphenylsiloxane copolymer, were coated on fused silica capillary columns and their gas
chromatographic properties were evaluated. Their selectivity was evaluated using both Rohrschneider–McReynolds constants and
triacylglycerol indices. The bis(dimethylsilyl)-m-carborane unit turned out to be equivalent to two dimethylsiloxy units and one half of a diphenylsiloxy unit. The m-carborane unit was found to cause a 15–25 K shift in the elution temperature between 120 and 360 °C. The working range was
from 20 and 0 °C to 380 °C for Dexsil 300 and Dexsil 400, respectively. The column bleeding levels at 380 °C were below 20
and 15 pA for Dexsil 300 and Dexsil 400, respectively. 相似文献