Photochemical retro-aldol type reactions of nitrobenzyl derivatives. Mechanistic variations in the elimination of nitrobenzyl carbanions from nitrobenzyl derivatives on photolysis

1986 ◽  
Vol 64 (9) ◽  
pp. 1949-1951 ◽  
Author(s):  
Peter Wan ◽  
S. Muralidharan
Keyword(s):  
Aqueous Solution ◽  
Leaving Group ◽  
Ph Dependent

The photochemical retro-aldol type reactions of several nitrobenzyl derivatives are reported. The reactions are observed only in aqueous solution with quantum efficiencies being pH dependent for several derivatives, consistent with the existence of several mechanistic pathways for reaction. The primary photochemical event is believed to involve the generation of a nitrobenzyl carbanion, which acts as a photolabile leaving group in these reactions, and the generation of an oxocarbocation (or oxocarbocation-derived) fragment.

scholarly journals Synthesis of pH-Sensitive and Self-Fluorescent Polymeric Micelles Derived From Rosin and Vegetable Oils via ATRP

2021 ◽  
Vol 9 ◽  
Author(s):  
Juan Yu ◽  
Chaoqun Xu ◽  
Chuanwei Lu ◽  
Qian Liu ◽  
Jifu Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Vegetable Oils ◽  
Renewable Resources ◽  
Polymeric Micelles ◽  
Drug Loading ◽  
Dehydroabietic Acid ◽  
Great Promise ◽  
Loading Capacity ◽  
Carboxylic Groups ◽  
Ph Dependent

Preparation and application of sustainable polymers derived from renewable resources are of great significance. The aim of this study is to synthesize a kind of sustainable polymeric micelles from rosin and vegetable oils via atom transfer radical polymerization (ATRP) and to investigate the doxorubicin delivery properties of these micelles. Dehydroabietic acid–based poly lauryl methacrylate (DA-PLMA) with narrow PDI of 1.13 was prepared in a well-controlled process using rosin as an ATRP initiator. Thereafter, carboxylic groups were introduced to form poly methacrylic acid (PMAA) moieties in DA-PLMA polymer via acid hydrolysis. The resulted DA-PLMA-PMAA could self-assemble in water to form pH-dependent polymeric micelles with a diameter of ∼65 nm and PDI as low as 0.105. Owing to the existence of rosin, DA-PLMA-PMAA micelles also showed self-fluorescence properties. In addition, Dox-loaded micelles were prepared in aqueous solution with the drug-loading capacity as high as 16.0% and showed sustained-release characteristics. These results demonstrate great promise for designing polymeric micellar from rosin and vegetable oils.

Thermoresponsive behavior of poly(N-isopropylacrylamide)s with dodecyl and carboxyl terminal groups in aqueous solution: pH-dependent cloud point temperature

2017 ◽  
Vol 295 (8) ◽  
pp. 1343-1349 ◽  
Author(s):  
Juraj Škvarla ◽  
Rahul K. Raya ◽  
Mariusz Uchman ◽  
Jiří Zedník ◽  
Karel Procházka ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Cloud Point ◽  
Solution Ph ◽  
Point Temperature ◽  
Cloud Point Temperature ◽  
Ph Dependent ◽  
Carboxyl Terminal

scholarly journals PH-Dependent Enantioselectivity of D-amino Acid Oxidase in Aqueous Solution

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Qingju Liu ◽  
Li Chen ◽  
Zhikun Zhang ◽  
Bibai Du ◽  
Yating Xiao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Amino Acid ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Ph Dependent

pH‐Dependent Metal‐Enhanced Fluorescence from CdTe@PAA Nanospheres near the Au Nanoparticles in Aqueous Solution

2012 ◽  
Vol 30 (7) ◽  
pp. 1490-1496 ◽  
Author(s):  
Rongqing Li ◽  
Chunlei Wang ◽  
Shuhong Xu ◽  
Zhuyuan Wang ◽  
Haibao Shao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Au Nanoparticles ◽  
Enhanced Fluorescence ◽  
Metal Enhanced Fluorescence ◽  
Ph Dependent

Octahedral cobalt(III) complexes of the chloropentanimine type. XXX. The thallium(III)-induced aquation of some cis-Halogeno(amine)bis(ethylenediamine)cobalt(III) cations in aqueous solution

1973 ◽  
Vol 26 (6) ◽  
pp. 1235 ◽  
Author(s):  
SC Chan ◽  
SF Chan
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Activation Parameters ◽  
Second Order ◽  
Alternative Possibility ◽  
Order Rate ◽  
Leaving Group ◽  
Activated Complex

The second-order rate constants for the thallium(III)-induced aquation of cis-[Co(en)2(RNH2)Cl]2+ cations, where R is H, Me, Et, Prn, and Pri, have been measured in aqueous solution over a range of temperatures, and the activation parameters calculated. The kinetic results are discussed in terms of a rapid pre-equilibrium formation of an activated complex Co-Cl-Tl, followed by a simple rate-determining aquation in which TlCl2+ acts as the leaving group, although the alternative possibility of a rate-determining attack by Tl3+ cannot be excluded. In the case of R = H, the investigations have been extended to the corresponding bromo cation which reacts some 50 times faster than its chloro analogue.

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