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131.
K. Jakop
ic J. Koji Z. Orhanovi Z. Stiploek A. Nagl A. Hergold 《Journal of heterocyclic chemistry》1992,29(1):107-112
Unlike comenic acid or most other 4-pyrones, methyl or ethyl comenate reacts with aromatic amines under mild conditions in the sense of ring contraction to 3-arylamino-2,4-dihydroxy-2-cyclopentenone-4-carboxylates. The structure of the new cyclopentenone derivatives were determined from their characteristic spectroscopic behaviour and was confirmed by X-ray crystallographic studies of compound Vb . 相似文献
132.
The T> and T< components of giant resonance levels in N>Z nuclei cannot be unambiguously identified in photonuclear reactions. In charged pion photoproduction, their analogs may be so identified (at least for the spinflip levels), as illustrated here with a 13C target. 相似文献
133.
134.
135.
M. Weindlmayr-Goettel I. Schindler S. Nagl und K. Steinbereithner 《Fresenius' Journal of Analytical Chemistry》1988,330(4-5):392-393
Ohne Zusammenfassung
Determination of hypoxanthine and xanthine in plasma by HPLC. Evaluation of the determination for assessing hypoxic cell damage in animal experiments相似文献
136.
William H. Watson Ante Nagl Ming-Jaw Don Michael G. Richmond 《Journal of chemical crystallography》2000,30(4):233-236
Treatment of Fe2(CO)6(2-PPhH)2 with BuLi (2 equiv.), followed by the addition of PtCl2 (dppe), affords the phosphido-bridged cluster Fe2(CO)6(3-PPh)2Pt(dppe). The Fe2Pt cluster was isolated and characterized in solution by IR and 31P NMR spectroscopy, and the molecular structure of Fe2(CO)6(3-PPh)2Pt(dppe) determined by X-ray diffraction analysis. Fe2(CO)6(3-PPh)2Pt(dppe) crystallizes in the orthorhombic space group Pbca, a = 17.539(3) Å, b = 21.490(2) Å, c = 22.959(3) Å, V = 8653.5(18) Å3, Z = 8, dcalc = 1.670 g cm–3; R = 0.0644, Rw = 0.0389 for 5040 observed reflections with I > 3(I). 相似文献
137.
Diudea MV Nagy CL Silaghi-Dumitrescu I Graovac A Janezic D Vikić-Topić D 《Journal of chemical information and modeling》2005,45(2):293-299
Various cages are constructed by using three types of caps: f-cap (derived from spherical fullerenes by deleting zones of various size), kf-cap (obtainable by cutting off the polar ring, of size k), and t-cap ("tubercule"-cap). Building ways are presented, some of them being possible isomerization routes in the real chemistry of fullerenes. Periodic cages with ((5,7)3) covering are modeled, and their constitutive typing enumeration is given. Spectral data revealed some electronic periodicity in fullerene clusters. Semiempirical and strain energy calculations complete their characterization. 相似文献
138.
Ante Ljubi
i 《Radiation Physics and Chemistry》2005,74(6):443-453
In this report the present status of axions in our understanding of particle physics and cosmology is given. A brief review of axion theory is presented and constraints on axion properties from laboratory searches and astrophysical and cosmological arguments are discussed. 相似文献
139.
Linear models for estimation of the first (K1), second (K2), and overall stability constant (beta2) based on the valence connectivity index of the third order ((3)chi(v)) were developed and checked on four sets of copper(II) chelates (with diamines, N-alkylated glycines, and naturally occurring amino acids, including their mixed complexes). Univariate models were valid when log K1 and log K2 values were linearly correlated, i.e., when there was no interaction between chelate rings. The univariate models proved applicable for estimation of all three stability constants of complexes with diamines and N-alkylated glycines, but for complexes with amino acids additional terms were needed (bivariate models). Models reproduced stability constants with an error usually less than 0.3 log K units. 相似文献
140.
The estimation of the overall stability constants β1 of copper(II) and nickel(II) chelates with dipeptides was performed by using the model with the valence connectivity index of the 3rd order (3χv). It was done by dividing β1 to its constituting constants K1 and Ka, and subsequently by dividing the basic set into subsets or treating the chelate rings as separate units. Altogether 15 copper(II) and eight nickel(II) chelates with dipeptides were investigated. Six models for the estimation of log K1 and pKa were checked, most of them by usage of indicator variables (for differentiation of copper(II) and nickel(II) complexes or subclasses of ligands). Estimates of log β1 gave the range of rms values from 0.19 to 0.27. For the best model, errors of estimates were less than 0.34. 相似文献