Molekula
Sulphur trioxide pyridine complex
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Sulphur trioxide pyridine complex is a reactive intermediate formed by the adduct of sulphur trioxide with pyridine, primarily used in sulfonation reactions, dye synthesis, and organic transformations requiring controlled SO₃ delivery. This complex offers a safer alternative to handling pure sulphur trioxide gas, improving reaction selectivity and yield in industrial and laboratory settings. CAS 26412-87-3, molecular formula C₅H₅NO₃S, molecular weight 159.17 g/mol. Store at ambient conditions in a cool, dry place. Signal word: Danger (corrosive, reacts violently with water). Molekula supplies Sulphur trioxide pyridine complex from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
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100 g — £45.80 per pack ex VAT · £54.96 inc. VAT
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Specifications
| Property | Value |
|---|---|
| Appearance | white powder |
| Assay | 98% min |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Transport Class | 8 |
| Packing Group | II |
| Acidity | Acid |
Identification
| Property | Value |
|---|---|
| SKU | 90026729 |
| CAS Number | 26412-87-3 |
| IUPAC Name | pyridine;sulfur trioxide |
| EC Number | 247-683-3 |
| Molecular Formula | C5H5NO3S |
| Molecular Weight | 159.17 |
| Exact Mass | 158.999 |
| SMILES | C1=CC=NC=C1.O=S(=O)=O |
| InChIKey | UDYFLDICVHJSOY-UHFFFAOYSA-N |
| InChI | InChI=1S/C5H5N.O3S/c1-2-4-6-5-3-1;1-4(2)3/h1-5H; |
| PubChem CID | 168533 |
| UN Number | UN3261 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 2942003500 |
| Tariff Code | 2942000090 |
Safety & GHS
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Corrosive
GHS05
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Health Hazard
GHS07
Hazard statements
- H290 May be corrosive to metals
- H302 Harmful if swallowed
- H314 (sub cat. 1B) Causes severe skin burns and eye damage
- H318 Causes serious eye damage
Precautionary statements
- P234 Keep only in original container
- P260 Do not breathe dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P303+361 IF ON SKIN (or hair): Remove immediately all contaminated clothing. Rinse with water/shower
- P304+340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Portuguese, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- Pyridine compound with sulfur trioxide (1:1)
- Pyridine sulfotrioxide
- Pyridine sulfur trioxide
- pyridine sulphur trioxide
- Pyridine, compound with sulphur trioxide
- pyridine; sulfonylideneoxidane
- SO3.Pyridine
- sulfur trioxide-pyridine
- Sulfur Trioxide-Pyridine; SO3-Py
- Sulphur trioxide--pyridine (1:1)
Frequently asked questions
What is sulphur trioxide pyridine complex commonly used for?
It is primarily used as a sulfonating agent in organic synthesis, particularly for the preparation of sulfonic acids and sulfonates.
What is the molecular formula and molecular weight of sulphur trioxide pyridine complex?
The molecular formula is **C₅H₅NO₃S**, and the molecular weight is **159.17 g/mol**.
How should sulphur trioxide pyridine complex be stored?
Store at **ambient temperature** in a tightly sealed container, away from moisture and incompatible materials.
What grade or purity is available for sulphur trioxide pyridine complex?
Molekula supplies this product in **high-purity research grade** (typically ≥98% purity).
Can Molekula supply sulphur trioxide pyridine complex in bulk quantities?
Yes, bulk quantities are available upon request—contact our sales team for pricing and lead times.
What documentation comes with an order of sulphur trioxide pyridine complex?
Each order includes a **Certificate of Analysis (CoA)**, Safety Data Sheet (SDS), and a product specification sheet.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.