نتایج جستجو برای: halogen compounds
تعداد نتایج: 230653 فیلتر نتایج به سال:
In the 1- (4-fluorophenyl) -2,3-dihydro-1 H-naphto- [1 and 2-e] [1 and 3] oxazine-3-n, there are 4 rings, respectively, rings from the side attached to the halogen They are named C, B, A, and D. Calculations and studies show that the amount of aromatics in the halogen-ring A in all cases has the highest number. In the B loop, the predicted aromatism level is zero, and in the ring C and D, relat...
The charge distribution of halogen atoms on organochlorine compounds can be highly anisotropic and even display a so-called σ-hole, which leads to strong halogen bonds with electron donors. In this paper, we have systematically investigated a series of chloromethanes with one to four chloro substituents using a polarizable multipole-based molecular mechanics model. The atomic multipoles accurat...
Halogen bonds are defined as interactions between halogens and a Lewis base in which the halogen (X) acts as the electrophilic species, and is typically explained by the presence of a σ-hole at the end of the C-X bond. Despite the important role of the halogen bond in intermolecularly interacting species, e.g. in acid-base reactions, enzyme inhibition and the supramolecular architecture, this i...
Halogen bonding between halide sites (in substituted organic molecules or inorganic halides) and Lewis bases is a rapidly progressing area of exploration. Investigations of this phenomenon have improved our understanding of weak intermolecular interactions and suggested new possibilities in supramolecular chemistry and crystal engineering. The capacity for halogen bonding is investigated at the...
A structure-activity relationship study concerning the antibacterial properties of several halogen-substituted tricyclic sulfur-containing flavonoids has been performed. The compounds have been synthesized by cyclocondensation of the corresponding 3-dithiocarbamic flavanones under acidic conditions. The influence of different halogen substituents on the antibacterial properties has been tested ...
In the combination of 5-fluorophenyl-1, 3, 7, 9-tetra methyl pyrido [2, 3, d, d, 5, 6 di pyrimidine -2, 4, 6, and 8 tetron, there are 4 rings, respectively, ring that is attached to the halogen ring A and, respectively, a ring The lower and the right to the left of the ring A are called C, B, and D. Calculations and studies show that the amount of aromatics in halogen-ring A in all cases has th...
It has previously been demonstrated that the rate of tumor induction in mice by chemical carcinogens of the hydrocarbon type is retarded by a series of compounds containing labile halogen atoms (9, 10). These halogen compounds ranged from chloro-acetal, a compound of relatively low reactivity, to a variety of highly active acid halides. The velocity constants of their reaction with cysteine und...
Materials of steam water cycles can suffer from corrosion induced by halide anions in feedwater. Organic halogen compounds in feedwater can be degraded and release halide anions under high temperature and pressure. Therefore it is necessary to be able to measure the organic halogen concentration. Existing measurements including Adsorbable Organic Halogens and Gas Chromatography are either not c...
In this paper, quantitative–structure–toxicity–relationship (QSTR) models are developed for predicting the toxicity of halogen, sulfur and chlorinated aromatic compounds. Two sets of compounds, containing mainly halogen and sulfur inorganic compounds in the first set and chlorinated aromatic compounds in the second, are investigated for their toxicity level with the aid of the conceptual Densit...
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