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101.
102.
JPC – Journal of Planar Chromatography – Modern TLC - The relative lipophilicity (RM0) and specific hydrophobic surface area of eight 1,2-benzisothiazol-3(2H)-one derivatives... 相似文献
103.
Versatility and synthetic potential of 1-(trimethylsilyloxy)-1,3-butadiene, 1-(trimethylsilyloxy)penta-1,3-diene, and their methyl substituted derivatives have been demonstrated in a modular synthetic methodology of stereodefined π-conjugated unsymmetrical, symmetrical two-dimensional, and octupolar polyenal structure. 相似文献
104.
This work contains results of computer simulation researches, which define requirements for measurement conditions, which should be fulfilled so that measurement results ensure allowable errors. They define: allowable measurement errors (interferogram's scanning) and conditions, which should fulfill computer programs, so that errors introduced by mathematical operations and computer are the smallest. 相似文献
105.
Brereton Richard G. Jansen Jeroen Lopes João Marini Federico Pomerantsev Alexey Rodionova Oxana Roger Jean Michel Walczak Beata Tauler Romà 《Analytical and bioanalytical chemistry》2018,410(26):6691-6704
Analytical and Bioanalytical Chemistry - The contribution of chemometrics to important stages throughout the entire analytical process such as experimental design, sampling, and explorative data... 相似文献
106.
Wojciech Duczmal Elzbieta Śliwińska Beata Maciejewska Bogdan Marciniec Hieronim Maciejewski 《Transition Metal Chemistry》1995,20(5):435-439
Summary Trisubstituted silanes, HSiR3-n
X
n
(R = Me or Et, X = Cl, OEt, or Ph; n = 0–3) oxidatively add to the complex [RhCl(cod)(1-hexene)] (cod = cycloocta-1,5-diene) to yield [RhCl(cod)(1-hexene)(H)(SiR3)] [(1)]. Subsequent steps of hydrosilylation follow, i.e. cis-insertion of the alkene (- rearrangement) and then reductive elimination of the product, according to the general Chalk and Harrod scheme. A quantitative correlation between the second order rate constant, k
1, of the oxidative addition (followed spectrophotometrically) at 20°C in benzene solution and the structure of the trisubstituted silane represented by Stereoelectronic parameters , and E' for the SiR3-n
X
n
groups was established. The maximal hydrosilylation rate followed by g.l.c., is strongly retarded by highly electronegative substituents X on silicon and results from the elimination rate of the hydrosilylation product from (1) and the maximal concentration of (1) in solution.Dedicated to Professor K. Rühlmann on the occasion of his 65th birthday. Part XXVII in the series Catalysis of Hydrosilylation; for Part XXVI see Polish J. Appl. Chem., 38, 169 (1994). 相似文献
107.
Adam Voelkel Beata Strzemiecka 《Colloids and surfaces. A, Physicochemical and engineering aspects》2006,280(1-3):177-181
The raw material—aloxite used during the manufacturing of grinding tools was characterized by means of inverse gas chromatography (IGC). The surface properties of the different types of aloxite were determined including: (i) the specific surface area; (ii) the dispersive component of surface free energy as well as the sensitivity of this parameter on the environment humidity; and (iii) acidity and basicity of the examined surfaces. The results of our experiments proved the usefulness of IGC in the characterization of this kind of materials. 相似文献
108.
Piotr Guga Boles?aw Karwowski Damian B?aziak Magdalena Janicka Andrzej Okruszek Beata R?bowska Wojciech J. Stec 《Tetrahedron》2006,62(11):2698-2704
The SP-isomer of 5′-OH-N4-benzoyl-2′-deoxycytidine-3′-O-(2-thio-4,4-pentamethylene-1,3,2-oxathiaphospholane) undergoes DBU-promoted intramolecular cyclization providing as a sole product SP-deoxycytidine cyclic 3′,5′-O,O-phosphorothioate. Unexpectedly, the RP-counterpart yields a mixture of products consisting of RP-deoxycytidine cyclic 3′,5′-O,O-phosphorothioate and macrocyclic oligo(deoxycytidine phosphorothioate)s. The results of molecular modeling indicate that the dychotomy observed for the RP substrate may result from remarkably higher energy of the corresponding transition states, caused by the presence of bulky ‘spiro’ pentamethylene substituent at the position C4 in the oxathiaphospholane ring. 相似文献
109.
Kowalski P Suder P Kowalska T Silberring J Duszyńska B Bojarski AJ 《Rapid communications in mass spectrometry : RCM》2003,17(18):2139-2146
Noncovalent complexes consisting of two protonated amines and a chloride anion were observed under electrospray ionization mass spectrometry (ESI-MS) conditions. The observed phenomenon was investigated for the hydrochlorides of buspirone, a well-known anxiolytic drug, and 23 other arylpiperazine derivatives that had been developed as serotonin 5-HT(1A) receptor ligands. Due to the major role of ionic interactions in a vacuum, it was proposed that the detected complexes were formed by NH(+)---Cl(-)---NH(+) bridges. It was found that complexation depended on structural features of the analyzed compounds. For derivatives with a shorter linker (three methylene groups) containing a terminal cyclic amide fragment, complex ions were not observed. It was postulated that, in the latter case, steric hindrance due to a terminal group could disturb ionic bridge formation. Since both the observed complexation and ligand-binding processes are driven by noncovalent forces, and a qualitative relationship between them was found (compounds with a 4-carbon chain always display higher affinity for 5-HT(1A) receptors than do their 3-carbon analogues), such ESI-MS studies may yield valuable information on ligand-receptor interactions. 相似文献
110.
Relation between the substituent effect and aromaticity 总被引:1,自引:0,他引:1
Krygowski TM Ejsmont K Stepień BT Cyrański MK Poater J Solà M 《The Journal of organic chemistry》2004,69(20):6634-6640