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51.
Adnan S. Abu‐Surrah Tony Debaerdemaeker Wolfgang Huhn Bernhard Rieger Martti Klinga Timo Repo Markku Leskel 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):e42-e43
In the title compound, [Pd(CH3)2(C27H26P2)]·0.5C7H8, the Pd atom is at the centre of an approximately square‐planar arrangement of two P atoms and two methyl groups. The P—Pd—P angle [93.19 (3)°] is significantly larger than that in the corresponding dichloride complex [Pd(dppp)Cl2]. The toluene molecule is disordered across an inversion centre. 相似文献
52.
José Molina Molina J. A. Dobado George L. Heard Richard F. W. Bader Markku R. Sundberg 《Theoretical chemistry accounts》2001,105(4-5):365-373
The electron pair density, in conjunction with the theory of an atom in a molecule, enables one to unambiguously determine
the nature of the bonding between the gallium atoms in bent [HGa-GaH]2−. The Ga-Ga bonding in the dianion at the experimental bond length is found to be the result of the sharing of two electron
pairs at the Hartree-Fock level of theory, the level consistent with the Lewis model of the electron pair.
Received: 27 July 2000 / Accepted: 4 October 2000 / Published online: 19 January 2001 相似文献
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Applying human and pig hepatic in vitro experiments for sulfur mustard study: Screening and identification of metabolites by liquid chromatography/tandem mass spectrometry 下载免费PDF全文
56.
Sirpa Peräniemi Jouko Vepsäläinen Heikki Mustalahti Markku Ahlgrén 《Fresenius' Journal of Analytical Chemistry》1992,344(3):118-122
Summary In a method developed for the determination of phosphorus in aqueous solutions, phosphorus was changed to the phosphate form, coprecipitated with hydrated iron(III) oxide, bound with activated charcoal and measured by EDXRF. The detection limit was 0.89 mg P/g activated charcoal. The method was used to determine the total phosphorus content of a waste water sample from a paper mill. Investigation of two sample destruction methods, dry ashing/HCl digestion and persulphate oxidation, showed the former to be more suitable for our purpose. 相似文献
57.
Markku S. Hannula 《ZDM》2007,39(3):197-203
Since the 1990s there has developed a strong cluster of research around the affect in mathematics in Finland. This review highlights some outcome of this work. It is argued that both theoretically and methodologically there has been a tendency to incorporate influences from several sources, which has provided a fertile ground for innovative research. Some of the empirical findings are also reviewed. 相似文献
58.
Edyta Piskorska Krystyna Lawniczak-Jablonska Iraida N. Demchenko Ewa Benko Markku Heinonen 《Mikrochimica acta》2004,145(1-4):159-163
X-ray photoelectron spectroscopy (XPS) is used to estimate phase and element contents of the composites based on cubic boron nitride. A composite is a mixture of several compounds and the use of traditional X-ray diffraction for phase analysis in many cases can be difficult. By using XPS, we were able to evaluate the atomic concentration of elements and the content of different compounds of each element. SEM and XPS showed that samples are heterogeneous. The TiB2 phase, expecting from thermodynamic calculations, was formed in both investigated samples of cBN/Ti3SiC2/TiC but in different amount. The Ti3SiC2 additive was found more chemically active then TiC. 相似文献
59.
Markku Rsnen 《Journal of Molecular Structure》1983,102(3-4):235-242
The association of formamide has been studied in argon. In the spectral region from 800 to 200 cm−1 several characteristic bands due to association were found and assigned to the out-of-plane bending modes of the NH group. The widths of these low-frequency bands are of the same order of magnitude as those of the fundamental bands of the monomer. By comparing the spectra of self-associated species with spectra of heteroassociated species between formamide and N,N-dimethyl formamide, it was possible to assign association bands to the open dimers as well as to the cyclic dimers. A band appearing upon warming at about 230 cm−1 has been assigned to a H-bond stretching mode. The results indicate that dimers trapped from the gas phase are predominantly open, and that both open and cyclic structures are formed upon diffusion-controlled association in the matrix. 相似文献
60.
The (NgHNg)+ cations (Ng = Ar and Kr) produced via the photolysis of HFAr, HFKr, and HBrKr solid mixtures are studied, with emphasis on their decay mechanisms. The present experiments provide a large variety of parameters connected to this decay phenomenon, which allows us to reconsider various models for the decay of the (NgHNg)+ cations in noble-gas matrices. As a result, we propose that this phenomenon could be explained by the neutralization of the solvated protons by electrons. The mechanism of this neutralization reaction probably involves tunneling of an electron from an electronegative fragment or another trap to the (NgHNg)+ cation. The proposed electron-tunneling mechanism should be considered as a possible alternative to the literature models based on tunneling-assisted or radiation-induced diffusion of protons in noble-gas solids. As a novel experimental observation of this work, the efficient formation of HArF molecules occurs at 8 K in a photolyzed HFAr matrix. It is probable that the low-temperature formation of HArF involves local tunneling of the H atom to the Ar-F center, which in turn supports the locality of HF photolysis in solid Ar. In this model, the decay of (ArHAr)+ ions and the formation of HArF molecules observed at low temperatures are generally unconnected processes; however, the decaying (ArHAr)+ ions may contribute to some extent to the formation of HArF molecules. 相似文献