1.Typical Experimental Conditions & Calculation
Step 1: Screening
To find out which SiliaBond® Metal Scavenger will better suit your need, we recommend performing some screening (on small scale) using the SiliaBond Metal Scavenger Kit (Product # K30730B) to quickly determine which scavenger presents the highest efficiency and make experiment optimization from there.
Step 2: Optimization
If, upon completion of the screening procedure, the scavenging is not completed and you are not satisfied with the scavenging efficiency or you wish to reduce the number of equivalents and the reaction time, the following steps should be undertaken:
- Increase the temperature of the scavenging reaction
- Modify the number of molar equivalents of the SiliaBond Metal Scavenger Change the reaction time
- Try a different and/or a mixture of SiliaBond Metal Scavengers
These parameters can be changed one at a time or simultaneously to improve the metal removal efficiency. It is important to underline that these scavengers are stable and work in any solvent.
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SiliaMetS® Thiol
SiliaMetS® Thiol (Si-Thiol) is a robust metal scavenger for a variety of metals including Pd, Pt, Cu, Ag and Pb under a wide range of conditions. It has been used in pharmaceutical processes up to the pilot plant scale. It is our most versatile metal scavenger and is the preferred metal scavenger for Pd(II), Cu, Ag, and Hg.
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SiliaMetS® Thiourea
SiliaMetS® Thiourea (Si-THU) is a versatile metal scavenger for all forms of palladium and is widely used in the pharmaceutical industry. It works particularly well in organic solvents. It can also be used to scavenge Ag, Pt, Ru, Rh and Hg. Once complexed with a transition metal, it has been reported as being an effective catalyst.
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SiliaMetS® Cysteine
SiliaMetS® Cysteine (Si-Cys) is the silica bound equivalent of the amino acid Cysteine. By attaching the molecule to the backbone via the amino group, the thiol group remains free and accessible for higher metal scavenging efficiency. It is a versatile metal scavenger for a variety of metals including Pd, Sn, Ru, Pt, Cu, Rh, Cd and Sc under a wide range of conditions and the preferred metal scavenger for tin residues.
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SiliaMetS® Dimercaptotriazine (DMT)
SiliaMetS® DMT (Si-DMT) is the silica bound equivalent of 2,4,6-trimercaptotriazine (trithiocyanuric acid). It is a versatile metal scavenger for a variety of metals including Cd, Co, Ni, Pd, Pt, Rh, and Ru under a wide range of conditions and the preferred metal scavenger for ruthenium catalysts.
TMT has been reported to efficiently remove palladium and heavy metals by precipitation. Unfortunately, its solubility in organic solvents causes problem. SiliaMetS DMT solves this issue and almost all solvents can now be used.
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SiliaBond® Amine
SiliaBond® Amine (Si-NH2) is an effective scavenger of acid chlorides, sulfonyl chlorides, isocyanates and other electrophiles. Si-NH2 has been shown to be effective metal scavenger and catalyst for Knoevenagel reactions. SiliaBond Amine is also used in chromatography as normal phase sorbent.
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SiliaBond® Amine nec
SiliaBond® Amine (Si-NH2) is an effective scavenger of acid chlorides, sulfonyl chlorides, isocyanates and other electrophiles. Si-NH2 has been shown to be effective metal scavenger and catalyst for Knoevenagel reactions. SiliaBond Amine is also used in chromatography as normal phase sorbent.
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SiliaMetS® Diamine
SiliaMetS® Diamine (Si-DIA) is a proven scavenger for metals and electrophiles. It scavenges acids, acid chlorides, anhydrides, aldehydes, isocyanates, and chloroformates as well as Pb, Ni, and Cd.
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SiliaMetS® Triamine
SiliaMetS® Triamine (SiliaMetS WAX-3, Si-TRI) is effective for scavenging metals such as Pb, Co, Ru and Pd. Our screening studies have shown it to be the preferred scavenger for Pb. It can also be used as a scavenger for acid chlorides, isocyanates and other electrophiles.
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SiliaMetS® Imidazole
SiliaMetS® Imidazole (Si-IMI) is a versatile metal scavenger for a variety of metals including Cd, Co, Cu, Fe, Ni, Pd, and Rh under a wide range of conditions and the preferred metal scavenger for iron catalysts.
SiliaMetS Imidazole can also be used as an amine base in systems that are generally sensitive to basic conditions compared to other SiliaMetS supported bases.
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SiliaMetS® TAAcOH
SiliaMetS® TAAcOH (SiliaMetS Triaminetetraacetic Acid) is a silica bound metal scavenger for Pd(0), Ni(0) and Cu. It is the supported version of EDTA in its free form. It is an effective scavenger for metals in low or zero oxidation states, which includes many of the most synthetically useful catalysts such as tetrakis-(triphenylphosphine)palladium(0).
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SiliaMetS® TAAcONa
SiliaMetS® TAAcONa or (or SiliaMetS Triaminetetraacetate, sodium salt) is a silica bound metal scavenger for Pd(II), Ni(II) and Cu. It is the supported version of EDTA in its sodium salt form. It is an effective scavenger for metals in higher oxidation state, 2+ or higher.
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SiliaMetS® Metal Scavenger Kit
Cysteine - DMT - Imidazole - Triamine - TAAcOH - TAAcONa - Thiol - Thiourea





