Supported sulfonic acids such as SiliaBond^® Propylsulfonic Acid (SiliaBond SCX-2) are in a class of strong acids widely used in different fields of synthetic organic chemistry. Their applications are well known and are used in a large number of settings going from drug discovery laboratories up to manufacturing processes. Among these applications, we denote their uses as acid catalysts, stationary phases for ion chromatography and basic impurity scavengers. Meanwhile, the most common use is probably as a strong cation exchanger (SCX) for the amine “Catch and Release” purification technique in SPE cartridges.

SiliCycle offers SiliaBond Propylsulfonic Acid (SCX-2) and SiliaBond Tosic Acid (SCX). Both are considered strong cation exchanger as they maintain a negative charge throughout the pH scale. The aromatic ring of the SiliaBond Tosic Acid makes it slightly more acidic than the other. However, tests have demonstrated that they both have comparable strength. The difference between the two products is mainly in the selectivity. SiliaBond SCX-2 presents a slightly more non-polar character than the SiliaBond SCX, thus reducing secondary non-polar interactions with compounds.

PRODUCT SPECIFICATIONS

MSDS-R51230B

APPLICATION NOTES
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POSTERS
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RELATED PUBLICATION

1. Electrochem. Comm., 11 (2009) 305

SiliaBond^® Tridecafluoro (Si-TDF) is a sorbent primarily used to separate fluorinated molecules. It can also be used in fluorous solid-phase extraction (FSPE) of fluorous-tag compounds as reported for the synthesis of oligosaccharide.³ It has a fluorine content that is between the SiliaBond Fluorochrom and the SiliaBond Pentafluorophenyl.

PRODUCT SPECIFICATIONS

MSDS-R63530B

RELATED PUBLICATIONS

1. J. Org. Chem., 73 (2008) 2058
2. Org. Lett. 9 (2007) 2285
3. Angew. Chem. Int. Ed., 40 (2001) 4433

SiliaBond^® Triethylamine (SiliaBond WAX-2) is a silica bound tertiary amine base and can be used in most applications requiring a tertiary amine, particularly as a HCl sponge. Silica bound ammonium salt by-products are easily separated by filtration. This triethylamine immobilized on silica gel can be used for the same applications as SiliaBond Dimethylamine. It is a very common supported tertiary amine.

SiliaBond Triethylamine is also used as weak anion exchanger (WAX) in SPE. It has a pka of ≈10.5 and is preferred over SiliaBond TMA Chloride (SAX) when performing “Catch and Release” purification of compounds bearing a permanent negative charge such as salts of sulfonic acids. Using SAX in this case could make the release of the compounds of interest difficult, not to say irreversible, due to the strong interaction between the two strong ions.

PRODUCT SPECIFICATIONS

MSDS-R76530B