andra - 29-9-2011 at 00:52
In what can I solubilize chitosan-phthalate? or just phthalates?? Because it seems that is not soluble in acetic acid and water, nor in DMSO, nor in
methanol or chloroform. I need it in order to do the NMR analysis.
Thanks!
Andra.
ThatchemistKid - 29-9-2011 at 09:50
I am not sure about dissolving your chitosan-phthalate considering it has that large amino sugar polymer group on it, but the NMR spectra of
chitosan-phthalate will be completely different from just "any phthalate"
para-phthalaic acid is I believe slightly soluble in methanol or ethanol from which it is recrystallized generally, also the phthalate ester is
soluble in its corresponding alcohol for the ethyl and methyl esters, probably also soluble in acetone. Do you have any d5-acetone or deuterated
alcohols in your NMR lab that you can use as solvents...what exactly are you trying to work with it was a little unclear. Also what is the strength of
your NMR's magnet?
[Edited on 29-9-2011 by ThatchemistKid]
Dr.Bob - 29-9-2011 at 18:24
Phthalate esters dissolve very well in methanol. We used to see them extracted from plastics frequently when people used certain plastic containers
to hold solvent or samples for NMR.
If you are desperate, you could try TFA or a mix of DMSO, methanol and CDCl3. Chitosan is not exactly a small molecule.
Bob
Ozone - 29-9-2011 at 18:31
My old research group used phthalic anhydride to add a low degree of substitution to disrupt the crystallinity of the material in order to get it into
solution. You may have over-substituted (or cross-linked--in this case your screwed) it. Have you tried toluene?
Did your material ppt in brine?
O3
Nicodem - 1-10-2011 at 01:37
What is "chitosan-phthalate"? Is that a phthalate salt of chitosan? An ester? An amide? Is it fully functionalized, partially or what? What do
"phthalates" in general have to do with your question? What makes you think other people can read your mind?
PS: Please open unanswerable and/or referenceless threads only in the Beginnings section where I'm moving this.
Ozone - 1-10-2011 at 08:03
Phthalimides... If everything goes well.
Here are a couple of citatations (I was from the Daly group and did a lot of the early modifications of Chitosan via reductive amination, etc.)
Besides the attached, see also:
1: Sajomsang W, Tantayanon S, Tangpasuthadol V, Daly WH. Quaternization of N-aryl
chitosan derivatives: synthesis, characterization, and antibacterial activity.
Carbohydr Res. 2009 Dec 14;344(18):2502-11. Epub 2009 Sep 30. PubMed PMID:
19863950.
2: Sajomsang W, Tantayanon S, Tangpasuthadol V, Thatte M, Daly WH. Synthesis and
characterization of N-aryl chitosan derivatives. Int J Biol Macromol. 2008 Aug
15;43(2):79-87. Epub 2008 Apr 15. PubMed PMID: 18514305.
3: Zhang C, Price LM, Daly WH. Synthesis and characterization of a trifunctional
aminoamide cellulose derivative. Biomacromolecules. 2006 Jan;7(1):139-45. PubMed
PMID: 16398508.
Cheers,
O3
Attachment: Daly et al 2010.pdf (412kB)
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Attachment: Kurita et al 2002 Biomacromol. 3 (1), pp 1-4.pdf (81kB)
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