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91.
Mezna Saleh Altowyan Saied M. Soliman Matti Haukka Nora Hamad Al-Shaalan Aminah A. Alkharboush Assem Barakat 《Molecules (Basel, Switzerland)》2022,27(13)
In the present work, a novel heterocyclic hybrid of a spirooxindole system was synthesized via the attachment of ferrocene and triazole motifs into an azomethine ylide by [3 + 2] cycloaddition reaction protocol. The X-ray structure of the heterocyclic hybrid (1″R,2″S,3R)-2″-(1-(3-chloro-4-fluorophenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl)-5-methyl-1″-(ferrocin-2-yl)-1″,2″,5″,6″,7″,7a″-hexahydrospiro[indoline-3,3″-pyrrolizin]-2-one revealed very well the expected structure, by using different analytical tools (FTIR and NMR spectroscopy). It crystallized in the triclinic-crystal system and the P-1-space group. The unit cell parameters are a = 9.1442(2) Å, b = 12.0872(3) Å, c = 14.1223(4) Å, α = 102.1700(10)°, β = 97.4190(10)°, γ = 99.1600(10)°, and V = 1484.81(7) Å3. There are two molecules per unit cell and one formula unit per asymmetric unit. Hirshfeld analysis was used to study the molecular packing of the heterocyclic hybrid. H···H (50.8%), H···C (14.2%), Cl···H (8.9%), O···H (7.3%), and N···H (5.1%) are the most dominant intermolecular contacts in the crystal structure. O···H, N···H, H···C, F···H, F···C, and O···O are the only contacts that have the characteristic features of short and significant interactions. AIM study indicated predominant covalent characters for the Fe–C interactions. Also, the electron density (ρ(r)) at the bond critical point correlated inversely with the Fe–C distances. 相似文献
92.
Explicit stress distributions for a hollow cylindrically orthotropic tube due to spinning are presented for immediate use in everyday engineering work. The solutions are obtained directly without using the stress function concept. Various boundary condition combinations present in practical applications are considered. Examples are given in order to indicate how the degree of anisotropy influences the stress distributions.Department of Mechanical Engineering, University of Oulu, P.O. Box 444, 90571 Oulu, Finland. Published in Mekhanika Kompozitnykh Materialov, Vol. 32, No. 6, pp 835–841, November–December, 1996. 相似文献
93.
94.
Matti Jakobsson 《BIT Numerical Mathematics》1985,25(4):593-603
A new technique for compression of character strings is presented. The technique is based on the use of a dictionary forest which is built simultaneously with the encoding and decoding. Codes representing substrings are addresses in the dictionary forest. Experimental results show that the length of the text can be reduced more than 50% with no a priori knowledge of the nature of the text. 相似文献
95.
96.
Sirpa Jääskeläinen Matti Haukka Jouni T Pursiainen 《Journal of organometallic chemistry》2004,689(6):1064-1070
An unsymmetric bidentate ligand (3-methyl-2-pyridyl)diphenylphosphane (P(Mepy)Ph2) is able to react with various tetranuclear transition metal clusters such as HRuCo3(CO)12, HRuRh3(CO)12 and Rh4(CO)12. The synthesis and crystal structures of HRuCo3(CO)10(P(Mepy)Ph2) (1), HRuRh3(CO)10(P(Mepy)Ph2) (2), RuRh2(CO)9(P(Mepy)Ph) (3) and Rh6(CO)14(P(Mepy)Ph2) (4) are described. In 1, 2 and 4 the phosphane ligand replaces the carbonyls and acts as a bridging bidentate P-N group. The formation of 3 includes degradation of both the metal cluster core and the ligand itself. One of the P-C bonds in the ligand is cleaved and the ligand caps a metal triangle with a bridging phosphido group together with the nitrogen donor. The reaction between dinuclear Rh2(CO)4Cl2 and P(Mepy)Ph2 gives a binuclear Rh2(μ-CO)Cl2(P(Mepy)Ph2)2 (5) with bridging ligands in a head-to-tail arrangement. The crystal structure is also given. 相似文献
97.
Eskola AJ Geppert WD Rissanen MP Timonen RS Halonen L 《The journal of physical chemistry. A》2005,109(24):5376-5381
The kinetics of the reactions of chlorinated methyl radicals (CH2Cl, CHCl2, and CCl3) with NO2 have been studied in direct measurements at temperatures between 220 and 360 K using a tubular flow reactor coupled to a photoionization mass spectrometer. The radicals have been homogeneously generated at 193 or 248 nm by pulsed laser photolysis of appropriate precursors. Decays of radical concentrations have been monitored in time-resolved measurements to obtain the reaction rate coefficients under pseudo-first-order conditions with the amount of NO2 being in large excess over radical concentrations. The bimolecular rate coefficients of all three reactions are independent of the bath gas (He or N2) and pressure within the experimental range (1-6 Torr) and are found to depend on temperature as follows: k(CH2Cl + NO2) = (2.16 +/- 0.08) x 10(-11) (T/300 K)(-1.12+/-0.24) cm3 molecule(-1) s(-1) (220-363 K), k(CHCl2 + NO2) = (8.90 +/- 0.16) x 10(-12) (T/300 K)(-1.48+/-0.13) cm3 molecule(-1) s(-1) (220-363 K), and k(CCl3 + NO2) = (3.35 +/- 0.10) x 10(-12) (T/300 K)(-2.2+/-0.4) cm3 molecule(-1) s(-1) (298-363 K), with the uncertainties given as one-standard deviations. Estimated overall uncertainties in the measured bimolecular reaction rate coefficients are about +/-25%. In the reactions CH2Cl + NO2, CHCl2 + NO2, and CCl3 + NO2, the products observed are formaldehyde, CHClO, and phosgene (CCl2O), respectively. In addition, a weak signal for the HCl formation has been detected for the CHCl2 + NO2 reaction. 相似文献
98.
Stavrakis S Koutsoupakis K Pinakoulaki E Urbani A Saraste M Varotsis C 《Journal of the American Chemical Society》2002,124(15):3814-3815
Time-resolved step-scan Fourier infrared spectroscopy has been used to study the CO-bound cbb(3)-type cytochrome c oxidase from Pseudomonas stutzeri at room temperature. We observe a single band in the FTIR spectrum at 1956 cm(-1) (beta-form). The time-resolved data indicate that upon photolysis, CO is transferred from heme b(3) (nu(CO) = 1956 cm(-1)) to CuB (nu(CO) = 2064 cm(-1)). The decay of the 2065 cm(-1) peak (t(1/2) = 120 +/- 16 ms) and the development of the 1956 cm(-1) peak (t(1/2) = 144 +/- 8 ms ) suggest that formation of the Fe-CO complex is concurrent with the decay of the CuB-CO complex. The intensity ratio of the Fe-CO/CuB-CO (2.15) remains constant for all data points, and thus we conclude that no fraction of CO escapes the binuclear center at 293 K. 相似文献
99.
A very simple method for determination of trace amount of Cu, Mn and Fe in beer by inductively coupled plasma spectrometry
(ICP-AES) was developed. The beer was directly introduced into the plasma, without dilution or adding of reagents, via a conventional
V-groove nebulizer. The only sample preparation used was degassing of the beer to remove CO2. By optimizing the ICP-AES parameters (RF power and Nebulizer gas flow rate) and by the appropriate choice of wavelengths
for measurements, sufficient accuracy for the determination of the trace metals was obtained. Various types of beers were
analysed by the direct ICP-AES method and for comparison, also with two other methods: by GFAAS and ICP-AES after decomposition.
No significant difference was found for Cu and Mn (ANOVA, 95% confidence level) using the three methods. This was normally
also the case for Fe; only in one case did the result of Fe by the direct method deviate from the other methods (10% lower
results). The limit of detection for the direct method was estimated to 1.1, 0.3, and 1.1 ng mL−1 for Cu, Mn, and Fe, respectively. 相似文献
100.
Veli-Matti Mukkala Matti Helenius Ilka Hemmil Jouko Kankare Harri Takalo 《Helvetica chimica acta》1993,76(3):1361-1378
The synthesis and luminescence properties are reported for 20 different chelates composed of 2,2′:6′,2″-terpyridine as the energy-absorbing and donating group, EuIIIand TbIII as the emitting ions, methylenenitrilo(acetic acids) as the stabel chelate-forming moieties, and isothiocyanato or(4,6-dichloro-1,3,5-triazin-2-yl)amino groups as the activated moieties for coupling to biomolecules. 相似文献