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991.
992.
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994.
Abbott T Akiba Y Beavis D Bloomer MA Bond PD Chasman C Chen Z Chu YY Cole BA Costales JB Crawford HJ Cumming JB Debbe R Engelage J Fung SY Gushue S Hamagaki H Hansen O Hayano RS Hayashi S Homma S Huang HZ Ikeda Y Juricic I Kang J Katcoff S Kaufman S Kimura K Kitamura K Kurita K Ledoux RJ Levine MJ Miake Y Morse RJ Moskowitz B Nagamiya S Olness J Parsons CG Remsberg LP Sakurai H Sarabura M Stankus P Steadman SG Stephans GS Sugitate T Tannenbaum MJ van Dijk JH Videbaek F Vient M Vincent P 《Physical review D: Particles and fields》1992,45(11):3906-3920
995.
The sediment sample is heated in an induction furnace in hydrogen chloride—argon; arsenic trichloride evolved is trapped and then swept into a d.c. plasma arc. Calcium sulfate addition enhances the signals and suppresses interference from organic matter. The limit of detection is 15 ng As; the relative standard deviation is 3.4% (n = 10) for 1.5μg As203. 相似文献
996.
Tomohiro Kimura 《Tetrahedron letters》2007,48(1):43-46
SmI2-induced reductive cyclization of (E)- and (Z)-β-alkoxyvinyl sulfones with aldehyde stereoselectively afforded 2,6-syn-2,3-trans- and 2,6-syn-2,3-cis-tetrahydropyrans, respectively. The product having a sulfonylmethyl group was converted to a cyclic ether having a methyl group by reduction with Raney-Ni. 相似文献
997.
The molar excess enthalpies of 1,2- and 1,3-propanediamine + 1- or 2-propanol and 1,2- and 1,3-propanediol + 1- or 2-propaneamine have been determined at 298.15 K using a twin-microcalorimeter for a series of runs over the whole range of mole fractions. All excess enthalpies were large exothermic, in particular, the systems of amines + propanediols were more than −5 kJ mol−1 at the minimum. Primary or secondary alcohols and amines showed systematically different enthalpic behaviors. Equilibrium constant K1 expressed in terms of mole fractions and standard enthalpy of the formation of a 1:1 complex have been evaluated by ideal mixtures of momomeric molecules and their associated complexes. 相似文献
998.
M. Fujisawa T. Matsushita M. A. Khan T. Kimura 《Journal of Thermal Analysis and Calorimetry》2005,82(2):319-321
Summary Excess molar heat capacities of (L-glutamine aqueous solution+D-glutamine aqueous solution) were determined by using a differential scanning calorimeter at temperatures between 293.15 and
303.15 K. Excess molar heat capacities are all negative. Excess molar heat capacities decrease with increasing temperature. 相似文献
999.
1000.
Mitsutoshi Kimura Akiyuki Iwata Masahiro Itoh Kazuki Yamada Tsutomu Kimura Noriyuki Sugiura Masaru Ishida Shinzi Kato 《Helvetica chimica acta》2006,89(4):747-783
A series of [(thioacyl)thio]‐ and (acylseleno)antimony and [(thioacyl)thio]‐ and (acylseleno)bismuth, i.e., (RCSS)xMR and (RCOSe)xMR (M = Sb, Bi, R1 = aryl, x = 1–3), were synthesized in moderate to good yields by treating piperidinium or sodium carbodithioates and ‐selenoates with antimony and bismuth halides. Crystal structures of (4‐MeC6H4CSS)2Sb(4‐MeC6H4) ( 9b′ ), (4‐MeOC6H4COSe)2Sb(4‐MeC6H4) ( 12c′ ), (4‐MeOC6H4COS)2Bi(4‐MeC6H4) ( 15c′ ), and (4‐MeOC6H4CSS)2BiPh ( 18c ) along with (4‐MeC6H4COS)2SbPh ( 6b ) and (4‐MeC6H4COS)3Sb ( 7b ) were determined (Figs. 1 and 2). These compounds have a distorted square pyramidal structure, where the aryl or carbothioato (= acylthio) ligand at the central Sb‐ or Bi‐atom is perpendicular to the plane that includes the two carbodithioato (= (thioacyl)thio), carboselenato (= acylseleno), or carbothioato ligand and exist as an enantiomorph pair. Despite the large atomic radii, the C?S ??? Sb distances in (RCSS)2MR1 (M = As, Sb, Bi; R1 = aryl) and the C?O ??? Sb distances in (RCOS)xMR (M = As, Sb, Bi; x = 2, 3) are comparable to or shorter than those of the corresponding arsenic derivatives (Tables 2 and 3). A molecular‐orbital calculation performed on the model compounds (MeC(E)E1)3?xMMex (M = As, Sb, Bi; E = O, S; E1 = S, Se; x = 1, 2) at the RHF/LANL2DZ level supported this shortening of C?E ??? Sb distances (Table 4). Natural‐bond‐orbital (NBO) analyses of the model compounds also revealed that two types of orbital interactions nS → σ and nS → σ play a role in the (thioacyl)thio derivatives (MeCSS)3?xMMex (x = 1, 2) (Table 5). In the acylthio‐MeCOSMMe2 (M = As, Sb, Bi), nO → σ contributes predominantly to the orbital interactions, but in MeCOSeSbMe2, none of nO → σ and nO → σ contributes to the orbital interactions. The nS → σ and nS → σ orbital interactions in the (thioacyl)thio derivatives are greater than those of nO → σ and nO → σ in the acylthio and acylseleno derivatives (MeCOE)3?xMMex (E = S, Se; M = As, Sb, Bi; x = 1, 2). ?The reactions of RCOSeSbPh2 (R = 4‐MeC6H4) with piperidine led to the formation of piperidinium diphenylselenoxoantimonate(1?) (= piperidinium diphenylstibinoselenoite) (H2NC5H10)+Ph2SbSe?, along with the corresponding N‐acylpiperidine (Table 6). Similar reactions of the bis‐derivatives (RCOSe)2SbR1 (R, R1 = 4‐MeC6H4) with piperidine gave the novel di(piperidinium) phenyldiselenoxoantimonate(2?) (= di(piperidinium) phenylstibonodiselenoite), [(H2NC5H10)+]2(PhSbSe2)2?, in which the negative charges are delocalized on the SbSe2 moiety (Table 6). Treatment of RCOSeSbR (R, R1 = 4‐MeC6H4) with N‐halosuccinimides indicated the formation of Se‐(halocyclohexyl) arenecarboselenoates (Table 8). Pyrolysis of bis(acylseleno)arylbismuth at 150° gave Se‐aryl carboselenoates in moderate to good yields (Table 9). 相似文献