Asked 21st Aug, 2022

Hi. Is the reaction between primary amine and Si-OH possible or not?

I saw this sentence .Hydroxyl group and amino group are the both nuclephilic. So no reaction will take place
I have prepared a sample and apparent physical properties show excellent coverage, but I do not how to explain. can anyone help me?

All Answers (2)

22nd Aug, 2022
James E Hanson
Seton Hall University
What kind of reaction?
surface Si-OH is relatively acidic.
amine is basic
so Si-OH + R3N -> Si-O- + R3N-H +
ionic forces will hold them together.
but if you wash with water they may desorb
if you wash with acidic water at a low enough pH to protonate Si-O- it will definitely desorb.
1 Recommendation
25th Aug, 2022
Sura Salim
University of Mosul
There is no interaction

Similar questions and discussions

EDC coupling of a primary amine to a succinylated protein does not work - what could I be missing?
4 answers
  • Wy ChenWy Chen
Dear Researchgate Community,
I am currently trying to couple taurine to a protein via EDC reaction. I have already tried the following attempts:
1) Direct coupling at either pH 5 - 6, by only using EDC
2) Direct coupling in a two-step reaction with the aid of NHS
3) Succinylation of the lysine residues of the protein, then coupling by EDC only at pH 6
For all attempts, I have used around 7-fold molar excess of EDC to expected -COOH groups of the protein, and around 9-fold molar excess of taurine, if not even up to 20-fold.
The way I analyze "coupling efficiency" is by measuring the zeta potential of the dialyzed product at different pH, in hopes that since taurine "masks" lysine residues and offers a sulfonic acid instead, the IEP must drift to more acidic pH values. After succinylation alone, such a drift could be observed, but after EDC reaction, I keep finding an IEP that is been even more basic than my native protein, which could be caused by side-reactions due to EDC. After EDC/NHS reaction, the IEP is unchanged compared to the native protein.
I have found a paper (doi: 10.1007/bf01046841) in which taurine was succesfully coupled to succinylated ovalbumin and couldn't find anything that I did differently in terms of pH and amounts of reagents. My only "weak points" would be the total volume I'm working with. Judging by this, I have always used more concentrated solutions of protein, taurine and EDC (by using less water). I wouldn't expect this to impact the reaction, but I might be very mistaken. Does anyone have experience or knowledge about this?
I would be very much thankful for any help. Could it really be the reaction volumes? Am I using too much EDC, facilitating the reaction to N-acyl-urea derivates (although I have found similar amounts of EDC in literature, and have used the same amount to successfully couple ethylenediamine to the same protein before)? Am I overlooking something vital?
Thank you in advance.

Related Publications

Thesis (Ph. D.) Massachusetts Institute of Technology. Dept. of Chemistry, 1957. Vita. Includes bibliographical references (leaves 71-74).
A chemical mystery featuring Sherlock Holmes and Dr. Watson. Keywords (Audience): High School / Introductory Chemistry
Got a technical question?
Get high-quality answers from experts.