Topic
Substituent
About: Substituent is a research topic. Over the lifetime, 42877 publications have been published within this topic receiving 516716 citations. The topic is also known as: side chain & side group.
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11 Mar 1974
TL;DR: In this paper, a method of inhibiting corrosion and scale formation in an aqueous system is disclosed which comprises the step of treating the said system with 0.1 to 500 parts per million by weight of the total Aqueous content of the system, of a composition which may additionally include zinc and which comprises a polymer selected from the group consisting of polymers having recurring units of the formula.
Abstract: A method of inhibiting corrosion and scale formation in an aqueous system is disclosed which comprises the step of treating the said system with 0.1 to 500 parts per million by weight of the total aqueous content of the said system, of a composition which may additionally include zinc and which comprises a polymer selected from the group consisting of: Polymers having recurring units of the formula: ##EQU1## WHEREIN M + may be H + , alkali metal cation, or quaternary ammonium cation of the formula: ##EQU2## wherein for all of the above formulas, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to 10 carbon atoms, and substituted alkyl of from one to 10 carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; and Wherein n is an integer of from 2 to 100; and polymers having recurring units of the formula: ##EQU3## WHEREIN R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to 10 carbon atoms, and substituted alkyl of from one to 10 carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; Wherein p is an integer of from 1 to 6; Wherein m is an integer of from 2 to 100; and Wherein n is an integer of from 2 to about 100, provided that, n not equal to m, the lesser of m or n is multiplied by a factor such that n = m.
81 citations
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TL;DR: In this paper, a conjugated polymer system with propargyl side chains and N-propargylpyridinum substituent was formed, which was shown to be completely soluble in water, methanol, dimethylformamide, and dimethyl sulfoxide, and well processable into thin homogeneous film.
Abstract: Poly-(2-ethynylpyridinum bromide) (PEPBP) having propargyl side chains was prepared by the direct polymerization of 2-ethynylpyridine and propargyl bromide under mild reaction conditions without any initiator and catalysts. The polymerization proceeded well to give PEPBP with propargyl side chains in relatively high yields. Various spectral data for the polymer structure indicated that the conjugated polymer system having N-propargylpyridinum substituent was formed. This ionic polymer was completely soluble in water, methanol, dimethylformamide, dimethyl sulfoxide, and N,N-dimethylacetamide and well processable into thin homogeneous film. The photoluminescence intensity (λmax = 760 nm) of this polymer increased as the temperature was increased. At 1 KHz and room temperature, this polymer has k′ = 2.9 and σ = 7.3 × 10−10 (S/cm). © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3151–3158, 2001
81 citations
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TL;DR: In this article, the electron-donating character of the substituent in the excited fluorenone and the hydrogen-bonding power of alcohol play important roles in determining the rate of dynamic quenching by alcohols.
Abstract: Substituent effects on intramolecular radiationless deactivation and hydrogen-bonding-induced quenching have been examined for various fluorenone derivatives. In toluene, triplet formation is the dominant process from the singlet excited state when an electron-withdrawing group is attached to the fluorenone moiety, whereas an electron-donating substituent promotes internal conversion. There is a clear correlation between the internal conversion rate constant and the lowest excited singlet state energy, which can be explained in terms of the energy gap law. It is shown that both the electron-donating character of the substituent in the excited fluorenone and the hydrogen-bonding power of alcohol play important roles in determining the rate of dynamic quenching by alcohols. The intermolecular hydrogen bonding with alcohols in the singlet excited state acts as an effective accepting mode of radiationless deactivation for fluorenones substituted with an electron-donating group. However, 2-NO2− and 2-COOCH3− d...
81 citations
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TL;DR: Domenicano et al. as discussed by the authors analyzed the deformation of the carbon skeleton of the benzene ring under substituent impact from the structures of 74 monosubstituted derivatives, as determined by ab initio MO calculations.
Abstract: The deformation of the carbon skeleton of the benzene ring under substituent impact has been analyzed from the structures of 74 monosubstituted derivatives, as determined by ab initio MO calculations. The geometry of the substituted ring is shown to contain valuable information on the electronegativity, resonance, and steric effects of the substituent, and also on other, more subtle effects, affecting primarily the length of the Cipso−Cortho bonds. The results obtained substantially augment previous knowledge from the analysis of experimental geometries (Domenicano, A.; Murray-Rust, P.; Vaciago, A. Acta Crystallogr., Sect. B 1983, 39, 457). Varying the electronegativity of the substituent causes a concerted change of the ring angles at the ipso, ortho, and para positions, coupled with a change in the Cipso−Cortho bond length. The values of the ipso angle span a remarkably wide range, 113−126°. Enhancing the resonance interaction between a substituent and the ring causes a complex pattern of angular distor...
81 citations
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TL;DR: In this article, a series of sulfur chelated dormant ruthenium olefin metathesis catalysts were presented, which were shown to possess the uncommon cis-dichloro arrangement and were mostly inactive at room temperature.
81 citations