A singular beta-cyclodextrin dimer, 1,10-phenanthroline-2,9-dimethyl-bridged-bis(6-monoammonio-beta-cyclodextrin) (phenBisCD, L), was synthesized. Its zinc complex (ZnL) continues to be prepared, indicated, and applied like a new catalyst for diester hydrolysis. The development constant (logK(ML)=9.56 /-.01) from the complex and deprotonation constant (pK(a)=8.18 /-.04) from the matched water molecule were based on a potentiometric pH titration at (298 /-.1) K. Hydrolytic kinetics of carboxylic acidity esters were carried out with (BNPC) and 4-nitrophenyl acetate (NA) as substrates. The acquired hydrolysis rate constants demonstrated that ZnL includes a high rate of catalysis for BNPC hydrolysis, giving a 3.89×10(4)-fold rate enhancement over uncatalyzed hydrolysis at 7.01, in accordance with merely a 42-fold rate enhancement for NA hydrolysis. >
Furthermore, the hydrolysis second-order rate constants of both BNPC and NA greatly increases with . Hydrolytic kinetics of the phosphate diester catalyzed by ZnL seemed to be looked into by utilizing bis(4-nitrophenyl) phosphate (BNPP) because the substrate. The dependence from the BNPP cleavage in aqueous buffer shows a sigmoidal curve by having an inflection point around 8.11, that was nearly just like the pK(a) value in the potentiometric titration. The k(cat) of BNPP hydrolysis marketed by ZnL was discovered to be 9.9×10(-4) M(-1) s(-1), that is comparatively greater than other reported Zn(II)-based systems. The potential intermediate for that hydrolysis of BNPP, , and NA catalyzed by ZnL is suggested based on kinetic and thermodynamic analysis.
Synonym: Bis(p-Nitrophenyl) Carbonate p,p’-Dinitrodiphenylcarbonate
Assay: =99% (HPLC)
Appearance: whitened to off-whitened solid