Mediating covalent crosslinking of single-chain nanoparticles through solvophobicity in organic solvents

2021 ◽  
Author(s):  
Georg M. Scheutz ◽  
Justine Elgoyhen ◽  
Kyle C. Bentz ◽  
Yening Xia ◽  
Hao Sun ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Reaction Rate ◽  
Single Chain ◽  
Covalent Crosslinking ◽  
Solvophobic Effect

The photoinduced intrachain crosslinking of coumarin-containing copolymers in various organic solvents was mediated through the solvophobic effect, providing control over the reaction rate and the compaction of the final single-chain nanoparticles.

Polar organic solvents accelerate the rate of DNA strand replacement reaction

The Analyst ◽  
2015 ◽  
Vol 140 (6) ◽  
pp. 2023-2028 ◽  
Author(s):  
Tianchi Zhang ◽  
Chunli Shang ◽  
Ruixue Duan ◽  
Abdul Hakeem ◽  
Zhenyu Zhang ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Reaction Rate ◽  
Replacement Reaction ◽  
Polar Organic Solvents ◽  
Dna Strand

Acceleration of the reaction rate by polar organic solvents during both simple and complicated DNA strand replacement reactions is reported.

scholarly journals Kinetics of the inhibition of plasminogen activators by the plasminogen-activator inhibitor. Evidence for ‘second-site’ interactions

1988 ◽  
Vol 251 (2) ◽  
pp. 327-332 ◽  
Author(s):  
J Chmielewska ◽  
M Rånby ◽  
B Wiman
Keyword(s):  
Plasminogen Activator ◽  
Active Site ◽  
Reaction Rate ◽  
Plasminogen Activator Inhibitor ◽  
Peptide Bond ◽  
Plasminogen Activators ◽  
Single Chain ◽  
Free Concentration ◽  
Enzyme Active Site ◽  
Activator Inhibitor

The reactions between plasminogen-activator inhibitor (PAI) and different plasminogen activators were studied in the presence of chromogenic peptide substrates for the enzymes. Our findings suggest that the rate constants for the reactions of PAI with single-chain tissue plasminogen activator (tPA), two-chain tPA, high-Mr urokinase and low-Mr urokinase are high and quite similar (1.6 X 10(7)-3.9 X 10(7) M-1.s-1). A free active site in the enzymes seems to be necessary for their reaction with PAI. Amino acids with antifibrinolytic properties did not interfere with the reactions. However, di-isopropyl phosphorofluoridate-inactivated tPA inhibited the reaction between PAI and all plasminogen activators in a similar way. These findings clearly demonstrated that a ‘second-site’ interaction, in addition to that between the enzyme active site and the inhibitor ‘bait’ peptide bond, is of importance for the high reaction rate. The reaction rate between PAI and single-chain tPA in the presence of an activator substrate (D-Ile-Pro-Arg p-nitroanilide) was decreased in the presence of fibrin. Fibrin caused a decrease in the Km for the single-chain tPA-substrate reaction. As a consequence, the ‘free’ concentration of single-chain tPA in the system decreased in the presence of fibrin, affecting the reaction rate between PAI and single-chain tPA. The phenomenon might be of physiological relevance, in the sense that single-chain tPA bound to fibrin in the presence of plasminogen would be protected against inactivation by PAI.

Recent development in functionalized ionic liquids as reaction media and promoters

2012 ◽  
Vol 90 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Wing-Leung Wong ◽  
Kwok-Yin Wong
Keyword(s):  
Ionic Liquids ◽  
Organic Solvents ◽  
Chemical Reactions ◽  
Reaction Rate ◽  
Bond Formation ◽  
Catalytic Reactions ◽  
Important Chemical ◽  
Reaction Media

The recent development in the use of functionalized ionic liquids as both reaction media and promoters is reviewed. Ionic liquids designed with special functionality can enhance the reaction rate, selectivity, and productivity in various chemical reactions. In this context, some important chemical reactions involving C–C, C–O, C–N, and C–S bond formation in functionalized ionic liquids are discussed. These functionalized ionic liquids were found to provide distinct advantages over conventional organic solvents in these catalytic reactions.

scholarly journals SYNTHESIS AND COORDINATION PROPERTIES OF COBALT COMPLEXES OF 5-PHENYL-2,3,7,8,12,18-HEXAMETHYL-13,17-DIETHYLPORPHYRIN AND ITS NITRO-SUBSTITUTED IN ORGANIC SOLVENTS

2018 ◽  
Vol 61 (7) ◽  
pp. 44 ◽  
Author(s):  
Elizaveta M. Kuvshinova ◽  
Maria A. Bykova ◽  
Irina A. Vershinina ◽  
Olga V. Gornukhina ◽  
Tatyana V. Lyubimova ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Organic Solvents ◽  
Reaction Rate ◽  
Bathochromic Shift ◽  
Cobalt Complexes ◽  
Electronic Effects ◽  
Metal Porphyrin ◽  
Absorption Bands ◽  
Coordination Properties ◽  
Tetrapyrrole Macrocycle

5-Phenyl-2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin (1), 5-phenyl-10,20-dinitro-2,3,7,8,12,18-hexamethyl -13,17-diethylporphyrin (2), 5- (p-nitrophenyl) -2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin (3) weresynthesized. The kinetics of formation and dissociation of their cobalt complexes in pyridine and acetic acid was studied. It was found that the change in reactivity upon transition from porphyrin 1 to 2 during complexation in acetic acid is due to an increase in the degree of deformation of the tetrapyrrole aromatic nucleus and the electronic effect of nitro groups. This is manifested by a strong bathochromic shift of all absorption bands in electronic spectra. It is shown that the opposite effect of the deformation effect and the i-effect of nitro groups on the rate of the reaction of formation of metal porphyrin leads to an insignificant change in the kinetic parameters. In pyridine, which has weakly basic properties, the reaction rate increases sharply with the introduction of nitro groups at position of 10, 20 of the porphyrin core. This is due to the fact that the deviation of the tetrapyrrole macrocycle from planarity leads to an increase in the reaction rate. It was found that a spherical distortion of the planar structure of porphyrins (1-3) in the series 1<3<2 relatively slightly influence on the rate of dissociation of their cobalt complexes. Apparently, this is due to the fact that coordination of the cobalt cation leads to a more flat structure of the tetrapyrrole macrocycle and the electronic effects of the nitro groups is the main contribution to the rate of the dissociation reaction of porphyrins (1-3).Forcitation:Kuvshinova E.M., Bykova M.A., Vershinina I.A., Gornukhina O.V., Lyubimova T.V., Semeikin A.S. Synthesis and coordination properties of cobalt complexes of 5-phenyl-2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin and its nitro-substituted in organic solvents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 43-48

Anion-enhanced solvophobic effects in organic solvent

2018 ◽  
Vol 54 (61) ◽  
pp. 8502-8505 ◽  
Author(s):  
Josef M. Maier ◽  
Ping Li ◽  
Jackson S. Ritchey ◽  
Christopher J. Yehl ◽  
Ken D. Shimizu
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Solvophobic Effect ◽  
Solvophobic Effects

Molecular balanced measured a two-fold anion-induced enhancement of the solvophobic effect in organic solvents.

scholarly journals Light-fueled dynamic covalent crosslinking of single polymer chains in non-equilibrium states

2021 ◽  
Author(s):  
Daniel Kodura ◽  
Hannes A. Houck ◽  
Fabian R. Bloesser ◽  
Anja S. Goldmann ◽  
Filip E. Du Prez ◽  
...  
Keyword(s):  
Green Light ◽  
Synthetic Polymers ◽  
Equilibrium States ◽  
Polymer Chains ◽  
Single Chain ◽  
Covalent Crosslinking ◽  
Non Equilibrium

Synthetic polymers consume green light as fuel for intramolecular crosslinking, yielding non-equilibrium single chain nanoparticles that can be light-stabilised, kinetically and chemically trapped, or else unfold in the absence of light fuel.

Sign in / Sign up

Export Citation Format

Share Document