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Electron impact mass spectra of 65 pyrrolidine-N-oxyl derivatives have been assigned on a ‘peak-to-subgraph’ basis. On average, 50% of the total ion current is represented by structurally significant fragments associated with the nitroxide group. Secondary fragmentation is, as a rule, of a minor importance (30%), and fragments due to functional groups other than NO· seldom contribute more than 10% of the total ion current An enhanced specificity of fragmentation is observed when one or more of the 2,2, 5,5-methyl groups is replaced by a longer aliphatic chain or an aromatic group. 相似文献
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Hay Robert W. Pujari Mahesh P. Hideg Kaiman Hankovszky Olga H. 《Transition Metal Chemistry》1985,10(5):188-191
Summary The new macrocyclic ligand 7,14-o-hydroxyphenyl-5,12-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (1=L) has been prepared and complexes with copper(II), nickel(II) and cobalt(III) characterised. The nickel(II) complex is a yellow square-planar species, while the purple-red copper(II) complex is probably tetragonal in both the solid state and solution. The complexes appear to have an N-meso arrangement of the chiral nitrogen centres with the HOC6H4 groups occupying equatorial sites so that axial interactions with the metal do not occur. A variety oftrans-[CoLX2]ClO4 complexes (X=Cl, Br, NO2, or N3) have been characterised. 相似文献
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The spin-label technique has become an important method of studying biologically active molecules1–6. 相似文献
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Friedel-Crafts acylation of benzene or toluene with 5- and 6-membered nitroxide acid chloride, anhydrides derivatives (symmetrical or mixed) and aluminium chloride to aryl nitroxide ketones is described. 相似文献
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P. Sohr Gy. Mnyai K. Hideg H. O. Hankovszky L. Lex 《Magnetic resonance in chemistry : MRC》1980,14(2):125-128
The configuration of the diastereomeric pairs of 2-(3-hydroxy-3-methyl-5-phenyl-2,3-dihydrothiophen-2-yl)benzimidazole (1a,1b) and 2-(3-hydroxy-3-methyltetrahydrothiophen-2-yl)benzimidazole (2a, 2b), as well as that of the acyl and diacyl derivatives of 2a and 2b, and the structure of the dehydrated products formed by heating 1a or 1b, and 2a or 2b, were determined by IR, 1H and 13C NMR spectroscopy. 相似文献
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Tamás Kálai Péter Sáska Zoltán Szabó József Jekotilde Olga H. Hankovszky Kálmán Hideg 《合成通讯》2013,43(12):2041-2050
New 2-(2-di- and tetrahydrothienyl)benzimidazole compounds were prepared by the ring closure reactions of 2-(mercaptomethyl)benzimidazole1,2 (1) and α,β-unsaturated compounds activated with electron-withdrawing groups. 相似文献
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Robert W. Hay Bakir Jeragh Dharam P. Piplani Kalman Hideg Olga H. Hankovszky 《Transition Metal Chemistry》1979,4(4):234-236
Summary Metal complexes of the macrocyclic tetraaza ligand C-meso-7,14-diphenyl-5,6-butano-12,13-butano-1,4,8,11-tetraazacyclotetradeca-4,11-diene (L) are described. The copper(II) and nickel(II) complexes, isolated as their perchlorate salts, are 4-coordinate species. Several cobalt(III) complexes,trans-[CoLX2]+(X = Cl–, Br–, NO
2
–
or N
3
–
have also been characterised. The most probable stereochemistry of the ligand in the metal complexes is the C-meso-N-meso arrangements of the chiral centres. The N-meso stereochemistry leads to the bulky phenyl groups lying in equatorial positions. I.r. and d-d spectra are reported for the various complexes described. 相似文献
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