Cationic Reverse Micelles Create Water with Super Hydrogen-Bond-Donor Capacity for Enzymatic Catalysis: Hydrolysis of 2-Naphthyl Acetate by α-Chymotrypsin

2010 ◽  
Vol 16 (29) ◽  
pp. 8887-8893 ◽  
Author(s):  
Fernando Moyano ◽  
R. Dario Falcone ◽  
J. C. Mejuto ◽  
Juana J. Silber ◽  
N. Mariano Correa
Keyword(s):  
Hydrogen Bond ◽  
Reverse Micelles ◽  
Enzymatic Catalysis ◽  
Hydrogen Bond Donor ◽  
Donor Capacity ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

Effect of the Addition of a Nonaqueous Polar Solvent (Glycerol) on Enzymatic Catalysis in Reverse Micelles. Hydrolysis of 2-Naphthyl Acetate by α-Chymotrypsin

Langmuir ◽  
2004 ◽  
Vol 20 (14) ◽  
pp. 5732-5737 ◽  
Author(s):  
R. Darío Falcone ◽  
M. Alicia Biasutti ◽  
N. Mariano Correa ◽  
Juana J. Silber ◽  
Eduardo Lissi ◽  
...  
Keyword(s):  
Reverse Micelles ◽  
Polar Solvent ◽  
Enzymatic Catalysis ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

Bromine−AOT Charge-Transfer Complexes and Hydrogen-Bond Donor Ability of Water in AOT−isooctane−H2O Reverse Micelles and Water-in-Oil Microemulsions

1999 ◽  
Vol 103 (24) ◽  
pp. 4997-5004 ◽  
Author(s):  
Luis Garcia-Rio ◽  
Juan C. Mejuto ◽  
Renata Ciri ◽  
Iva B. Blagoeva ◽  
J. Ramon Leis ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Charge Transfer ◽  
Reverse Micelles ◽  
Charge Transfer Complexes ◽  
Hydrogen Bond Donor ◽  
Donor Ability

Hydrolysis of dimethylphenyltin(IV) and triphenyltin(IV) chlorides in different aqueous ethanol solutions

2008 ◽  
Vol 86 (8) ◽  
pp. 751-756 ◽  
Author(s):  
Morteza Jabbari ◽  
Farrokh Gharib ◽  
Mostafa Mohammadpour Amini ◽  
Amirreza Azadmehr
Keyword(s):  
Hydrogen Bond ◽  
Aqueous Ethanol ◽  
Formation Constants ◽  
Single Parameter ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Polarity Parameter ◽  
Wide Ph Range ◽  
Hydrogen Bond Acceptor Basicity ◽  
Hydrolysis Of

The hydrolysis of [(Me)2(Ph)Sn(IV)]+ and [(Ph)3Sn(IV)]+ has been investigated at 25 °C and different aqueous solutions of ethanol, using a combination of spectrophotometric and potentiometric techniques. The species formed together with their formation constants have been determined using the computer program Squad over a wide pH range of 1 to 11. The hydrolysis constants in different media were analyzed in terms of Kamlet and Taft parameters. Single-parameter correlation of the formation constants, K11 and K12, versus α (hydrogen-bond donor acidity), β (hydrogen-bond acceptor basicity), and π* (dipolarity/polarizability) for both cases are relatively poor in all solutions, but multiparameter correlation represents significant improvement with regard to the single-parameter models. In this work, we have also used the normalized polarity parameter, ETN, alone and in combination with the Kamlet–Taft parameter to find a better correlation of the formation constants in different aqueous ethanol solutions.Key words: dimethylphenyltin(IV) chloride, triphenyltin(IV) chloride, hydrolysis constant, aqueous ethanol solutions, solvent effect.

scholarly journals Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

2019 ◽  
Vol 15 ◽  
pp. 167-186 ◽  
Author(s):  
Falco Fox ◽  
Jörg M Neudörfl ◽  
Bernd Goldfuss
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
High Activation ◽  
Activation Barriers ◽  
Oh Groups ◽  
Ketene Acetals ◽  
Silyl Ketene Acetals ◽  
Computational Analyses ◽  
Hydrolysis Of

Biphenyl-2,2’-bisfenchyloxydichlorosilane (7, BIFOXSiCl2) is synthesized and employed as precursor for the new silanols biphenyl-2,2’-bisfenchyloxychlorosilanol (8, BIFOXSiCl(OH)) and biphenyl-2,2’-bisfenchyloxysilanediol (9, BIFOXSi(OH)2). BIFOXSiCl2 (7) shows a remarkable stability against hydrolysis, yielding silanediol 9 under enforced conditions. A kinetic study for the hydrolysis of dichlorosilane 7 shows a 263 times slower reaction compared to reference bis-(2,4,6-tri-tert-butylphenoxy)dichlorosilane (14), known for its low hydrolytic reactivity. Computational analyses explain the slow hydrolyses of BIFOXSiCl2 (7) to BIFOXSiCl(OH) (8, E a = 32.6 kcal mol−1) and BIFOXSiCl(OH) (8) to BIFOXSi(OH)2 (9, E a = 31.4 kcal mol−1) with high activation barriers, enforced by endo fenchone units. Crystal structure analyses of silanediol 9 with acetone show shorter hydrogen bonds between the Si–OH groups and the oxygen of the bound acetone (OH···O 1.88(3)–2.05(2) Å) than with chlorosilanol 8 (OH···2.16(0) Å). Due to its two hydroxy units, the silanediol 9 shows higher catalytic activity as hydrogen bond donor than chlorosilanol 8, e.g., C–C coupling N-acyl Mannich reaction of silyl ketene acetals 11 with N-acylisoquinolinium ions (up to 85% yield and 12% ee), reaction of 1-chloroisochroman (18) and silyl ketene acetals 11 (up to 85% yield and 5% ee), reaction of chromen-4-one (20) and silyl ketene acetals 11 (up to 98% yield and 4% ee).

Aliphatic Carboxylic Acid as Hydrogen-Bond Donor for Converting CO2 and Epoxide into Cyclic Carbonate under Mild Conditions

2021 ◽  
Author(s):  
Zheng Wang ◽  
Yajun Wang ◽  
Qianjie Xie ◽  
Zhiying Fan ◽  
Yehua Shen
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Value Added ◽  
Cyclic Carbonate ◽  
Hydrogen Bond Donor ◽  
Title Reaction ◽  
Aliphatic Carboxylic Acid ◽  
Mild Conditions ◽  
Atmospheric Carbon

The coupling of CO2 and epoxide is promising way to reduce atmospheric carbon by converting it into value-added cyclic carbonate. Pursuing efficient catalysts is highly attractive for the title reaction....

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