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31.
Hemlata Agarwala Dipl.‐Chem. Thomas Michael Scherer Dr. Somnath Maji Dr. Tapan Kumar Mondal Dr. Shaikh M. Mobin Dr. Jan Fiedler Prof. Dr. Reyes Jiménez‐Aparicio Prof. Dr. Wolfgang Kaim Prof. Dr. Goutam Kumar Lahiri 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(18):5667-5675
The diruthenium(III) compound [(μ‐oxa){Ru(acac)2}2] [ 1 , oxa2?=oxamidato(2?), acac?=2,4‐pentanedionato] exhibits an S=1 ground state with antiferromagnetic spin‐spin coupling (J=?40 cm?1). The molecular structure in the crystal of 1? 2 C7H8 revealed an intramolecular metal–metal distance of 5.433 Å and a notable asymmetry within the bridging ligand. Cyclic voltammetry and spectroelectrochemistry (EPR, UV/Vis/NIR) of the two‐step reduction and of the two‐step oxidation (irreversible second step) produced monocation and monoanion intermediates (Kc=105.9) with broad NIR absorption bands (ε ca. 2000 M ?1 cm?1) and maxima at 1800 ( 1 ?) and 1500 nm ( 1 +). TD‐DFT calculations support a RuIIIRuII formulation for 1 ? with a doublet ground state. The 1 + ion (RuIVRuIII) was calculated with an S=3/2 ground state and the doublet state higher in energy (ΔE=694.6 cm?1). The Mulliken spin density calculations showed little participation of the ligand bridge in the spin accommodation for all paramagnetic species [(μ‐oxa){Ru(acac)2}2]n, n=+1, 0, ?1, and, accordingly, the NIR absorptions were identified as metal‐to‐metal (intervalence) charge transfers. Whereas only one such NIR band was observed for the RuIIIRuII (4d5/4d6) system 1 ?, the RuIVRuIII (4d4/4d5) form 1 + exhibited extended absorbance over the UV/Vis/NIR range. 相似文献
32.
Several 3-amantadinyl-2-[(2-substituted benzylidenehydrazinyl)methyl]-quinazolin-4(3H)-ones (5a–5l) were prepared by the reaction of 3-amantadinyl-2-hydrazinylmethyl substituted quinazolin-4(3H)-ones (4a–4b) with various substituted aromatic aldehydes. Cycloaddition of compounds (5a–5l) with thioglycolic acid in the presence of anhydrous zinc chloride yielded 3-amantadinyl-2-[((substitutedphenyl)-4-oxo-thiazolidin-3-yl)methylamino]-quinazolin-4(3H)-ones (6a–6l). Compounds 5a–5l on further reaction with chloro acetyl chloride in the presence of triethylamine gave 3-amantadinyl-2-[((substitutedphenyl)-3-chloro-2-oxo-azetidin-1-yl)methylamino]-quinazolin-4(3H)-ones (7a–7l). The compounds 5a–5l, 6a–6l and 7a–7l were screened for their antiparkinsonian activity. The most active compound was 6g i.e. 3-amantadinyl-6-bromo-2-[((3,4-dimethoxyphenyl)-4-oxo-thiazolidin-3-yl)methylamino]-quinazolin-4(3H)-ones. Structures of the newly synthesized compounds were established on the basis of elemental and spectral (IR, 1H NMR and mass) analysis. 相似文献
33.
Hemlata Kaur Sunil Kumar Archana Chaudhary Ashok Kumar 《Arabian Journal of Chemistry》2012,5(3):271-283
Various 2-((2-((5-benzylideneamino)-1,3,4-oxa/thiadiazol-2-yl)methyl)hydrazinyl) methyl)benzo[b][1,4]oxa/thiazepin-4(5H)-ones (4a–4l), 2-((2-((5-(4-oxo-2-substitutedphenyl thiazolidin-3-yl)-1,3,4-oxa/thiadiazol-2-yl)methyl)hydrazinyl)methyl)benzo [b] [1,4]oxa/thiazepin-4(5H)-ones (5a–5l) and 2-((2-((5-(3-chloro-2-(substitutedphenyl)-4-oxoazetidin-1-yl)-1,3,4-oxa/thia diazol-2-yl)methyl)hydrazinyl)methyl)benzo[b][1,4]oxa/thiazepin-4(5H)-ones (6a–6l) have been synthesized. The structures of these compounds have been established by elemental (C, H, N) and spectral (IR, 1H-NMR and Mass) analysis. The synthesized compounds were screened for their antipsychotic and anticonvulsant activities. Compound 5l was found to be the most active compound of this series. 相似文献
34.
Journal of Radioanalytical and Nuclear Chemistry - Activity concentrations of natural (40K, 226Ra, 228Ra, 232Th, 238U) and artificial (134Cs, 137Cs) radionuclides were measured in powdered milk... 相似文献
35.
An efficient, mild, and expeditious synthetic protocol has been developed for the synthesis of structurally diverse 3-amino-imidazo[1,2-a]pyridines, involving a three-component, one-pot cyclocondensation reaction of 2-aminobenzothiazole/2-aminoazines, ethyl isocyanoacetate/tert-butyl isocyanides, and pyrazole-3(4)-carbaldehyde/substituted aromatic carbonyl compounds in 45 min. using In(OTf)\(_{3}\) as a catalyst in toluene. Mild reaction conditions, high atom economy, operational simplicity, short reaction time, and structural diversity with high product conversion are among the advantages of the present synthetic protocol. 相似文献
36.
Dinitrogen-trioxide reacts with rhodium(I) complexes and with rhodium trichloride trihydrated in presence of triphenylphosphine and triphenylarsine to give rhodium(III) nitrosylnitro complexes and rhodium(III) nitrosyl complexes which are characterized by ir spectra, magnetic measurement and elemental analyses. 相似文献
37.
Osmium(VIII) produces two coloured species with lambda(max) 680 nm (green) and 530 nm (red) with excess of 2-amino-8-naphthol-3,6-disulphonic acid in aqueous solution. The green complex is stable between pH 2.5 and 8.0 and the red complex between pH 11.0 and 12.0. The effects of temperature and time, reagent concentration, optimum conditions for the spectrophotometric determination of trace amounts of osmium, and other variables, have been studied at pH 11.5. At this pH, other platinum metals do not interfere. The sensitivity of the colour reaction is 0.2 microg/cm(2) and the system conforms to Beer's law over a concentration range of 1.5-10 microg of osmium. 相似文献
38.
The ruthenium trichloride hydrate and osmium tricholide react with (NSCl)3 in presence of triphenylphosphine and triphenylarsine to give thionitrosyl complexes M(NS)Cl3L2 (M) ? Rn, or Os; L ? PPh3 or AsPh3. 相似文献
39.
40.
Summary Vanadium(V) reacts with 7-amino-1-naphthol-3,6-disulphonic acid (2 R-acid) in the ratio 21, forming a red coloured chelate having maximum absorbance at 470 nm. The composition of the chelate has been found by the continuous variations and the mole ratio methods. The system obeys Beer's law between a range of 1.72 to 30.9 p. p. m. of vanadium and the sensitivity is 0.17g/cm2 at pH 2.0, The reagent is found to be fairly selective for vanadium.
Zusammenfassung Vanadin(V) reagiert mit 7-Amino-l-naphthol-3,6-disulfonsäure im Ver-hältnis 21 und bildet ein rotes Chelat mit dem Absorptionsmaximum bei 470 nm, dessen Zusammensetzung nachJob bestimmt wurde. Zwischen 1,72 und 30,9 ppm V ist das Beersche Gesetz erfüllt. Die Empfindlichkeit beträgt 0,17g/cm2 (Sandell) bei pH 2,0. Das Reagens ist für Vanadin ziemlich selektiv.相似文献