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91.
Schwaighofer A Schroeter T Mika S Laub J ter Laak A Sülzle D Ganzer U Heinrich N Müller KR 《Journal of chemical information and modeling》2007,47(2):407-424
Accurate in silico models for predicting aqueous solubility are needed in drug design and discovery and many other areas of chemical research. We present a statistical modeling of aqueous solubility based on measured data, using a Gaussian Process nonlinear regression model (GPsol). We compare our results with those of 14 scientific studies and 6 commercial tools. This shows that the developed model achieves much higher accuracy than available commercial tools for the prediction of solubility of electrolytes. On top of the high accuracy, the proposed machine learning model also provides error bars for each individual prediction. 相似文献
92.
93.
This work is part of an effort to develop chelating agents for stable binding and easy conjugation of Re-188 to biologically interesting structures. Starting from the well-known in vivo stability of [(188)ReO(DMSA)(2)](-), we want to exploit this coordination system for the design of (188)ReO(V) chelates, which are stable toward reoxidation to perrhenate and toward ligand exchange under all conditions of radiopharmaceutical development. Therefore, a new type of tetradentate ligand has been synthesized by bridging two molecules of N,N'-diisobutyl-2,3-dimercaptosuccinamide with N-(3-aminopropyl)propane-1,3-diamine. The resulting stereoisomeric tetrathiolato S(4) ligand of composition ((i)()Bu)(2)N(O)C-C(SH)-C(SH)-C(O)NH-(CH(2))(3)-NH-(CH(2))(3)-NHC(O)-C(SH)-C(SH)-C(O)N((i)Bu)(2) forms anionic five-coordinate oxorhenium(V) complexes by a ligand-exchange reaction of NBu(4)[ReOCl(4)] in methanol. In the absence of a base, the compounds were isolated as "betaine", [ReO(S(4))], with the protonated nitrogen of the bridge serving as an internal "counterion". Two representatives have been fully characterized in both the solid and solution states and found to adopt the expected square-pyramidal coordination geometry. The equatorial plane is formed by four thiolate sulfur atoms, whereas the oxygen occupies the apical position. The orientation of the metal oxo group is exo in relation to the carbamido groups in both isomers. Both complexes are stereoisomeric regarding the junction of the triamine chain. 相似文献
94.
95.
Florian Breitsameter Hans-Peter Schrdel Alfred Schmidpeter Heinrich Nth Susana Rojas-Lima 《无机化学与普通化学杂志》1999,625(8):1293-1300
Ylide Adducts of Pentele Trichlorides Ylides Ph3PCR2 form 1 : 1 adducts with PCl3, AsCl3 und SbCl3. The addition of HCl to dichlorophosphanyl- und dichloroarsanyl ylides also leads to such adducts. In solution the PCl3 adducts 2 are dissociated into ions. For the AsCl3 adducts 3 b and 3 e of triphenylphosphonium ethylide and isopropylide X-ray analyses show distinctly different degrees of transition from a zwitterionic ψ-tbp to a cationic ψ-tetrahedral structure. The SbCl3 adduct 4 b of the triphenylphosphonium ethylide on the other hand forms a rather asymmetric dimer and approaches a square-pyramidal geometry at the antimony atom. The 2 : 1 ylide adducts 11 with PCl3 form in solution the dications (Ph3PCR2)2PCl2+. The 2 : 3 adduct 15 of triphenylphosphonium methylide to AsCl3 also has an ionic structure in the crystal. There are cations (Ph3PCH2)2AsCl2+, which pairwise join with two AsCl3 molecules to form doubly charged supracations in the presence of As2Cl82– as counterions. 相似文献
96.
97.
Siemeling U Bausch K Fink H Bruhn C Baldus M Angerstein B Plessow R Brockhinke A 《Dalton transactions (Cambridge, England : 2003)》2005,(14):2365-2374
The new diimine ligand 3,8-di-n-pentyl-4,7-di(phenylethynyl)-1,10-phenanthroline (1) was used for the synthesis of a range of Pt(II) complexes, viz.[Pt(1)Cl2], [Pt(1)(C triple bond C-Ph)2], [Pt(1)(C triple bond C-Fc)2] and [Pt(1)(C triple bond C-p-C6H4-C triple bond C-Fc)2](Fc = ferrocenyl). Crystal structure analyses were performed for [Pt(1)Cl2] and [Pt(1)(C triple bond C-Ph)2] and revealed that the di(acetylide)pi-tweezer of the latter binds a molecule of chloroform through C-H...pi hydrogen bonds. The redox and optical properties of 1 and its complexes were investigated by (spectro-)electrochemistry, UV-Vis and luminescence spectroscopy, and an energy level diagram was derived for [Pt(1)(C triple bond C-Fc)2] and related compounds on the basis of the data collected. The ferrocenyl-substituted Pt(II) complexes are donor-sensitiser assemblies. Intramolecular quenching of the photoexcited Pt(II) diimine unit leads to very short luminescence lifetimes for [Pt(1)(C triple bond C-p-C(6)H(4)-C triple bond C-Fc)2](2 ns) and [Pt(1)(C triple bond C-Fc)2](0.3 ns), as opposed to [Pt(1)(C triple bond C-Ph)2](0.7 micros). Excimer formation has been observed for [Pt(1)(C triple bond C-Ph)(2)] at room temperature in dichloromethane and at low temperatures in frozen glassy dichloromethane and 2-methyltetrahydrofuran solution, but not in the solid state. 相似文献
98.
Oriňák Andrej Vering Guido Arlinghaus Heinrich F. Andersson Jan T. Halas Ladislav Oriňáková Renáta Turčániová Ľudmila 《平面色谱法杂志一现代薄层色谱法》2005,18(1):44-50
JPC – Journal of Planar Chromatography – Modern TLC - A new hyphenated technique that enables coupling of thin-layer chromatography (TLC) with time-of-flight secondary-ion mass... 相似文献
99.
100.
Tim Steinke Dr. Patrick Wonner Dr. Richard M. Gauld Dr. Sascha Heinrich Prof. Dr. Stefan M. Huber 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(47):e202200917
Recently, chalcogen bonding has been investigated in more detail in organocatalysis and the scope of activated functionalities continues to increase. Herein, the activation of imines in a Povarov [4+2] cycloaddition reaction with bidentate cationic chalcogen bond donors is presented. Tellurium-based Lewis acids show superior properties compared to selenium-based catalysts and inactive sulfur-based analogues. The catalytic activity of the chalcogen bonding donors increases with weaker binding anions. Triflate, however, is not suitable due to its participation in the catalytic pathway. A solvent screening revealed a more efficient activation in less polar solvents and a pronounced effect of solvent (and catalyst) on endo : exo diastereomeric ratio. Finally, new chiral chalcogen bonding catalysts were applied but provided only racemic mixtures of the product. 相似文献