Coumarin 343

Coumarin 343 is a versatile fluorescent laser dye with applications in laser physics, spectroscopy, and biological imaging.

Primary applications:

• Laser spectroscopy: Gain medium for tunable dye lasers (460-540 nm range)
• Fluorescence microscopy: Bright blue-green fluorophore for cellular imaging
• Flow cytometry: Compatible with 488 nm laser excitation
• Fluorescent sensing: pH indicators, ion sensors, environmental monitoring
• Analytical chemistry: HPLC detection, quantum yield standards
• Materials science: OLED dopant, polymer labeling

Key advantages: High quantum yield (0.6-0.8), large Stokes shift (47 nm), excellent photostability, solvent-sensitive fluorescence, and compatibility with standard excitation sources (Ar-ion laser 488 nm, blue LED, xenon lamps).

Coumarin 343 has well-characterized spectral properties in the blue-green region.

Spectral characteristics:

• Excitation maximum: ~443 nm (in ethanol)
• Emission maximum: ~490 nm (in ethanol)
• Stokes shift: ~47 nm (large separation)
• Extinction coefficient: ~46,000 M⁻¹cm⁻¹
• Quantum yield: 0.6-0.8 (solvent-dependent)
• Fluorescence: Bright blue-green

Compatible excitation sources:

• Argon-ion laser (488 nm line) – slightly red-shifted but works
• Blue LED (440-460 nm) – optimal match
• Xenon arc lamps with appropriate filters
• Nitrogen laser (337 nm) – via multiphoton absorption

Solvent effects: Spectral properties shift with solvent polarity. Ethanol is standard reference solvent. In aqueous media, expect slight red-shift. Always verify in your specific solvent system.

Proper solution preparation ensures optimal fluorescence performance and dye stability.

Stock solution preparation:

• Recommended solvent: Ethanol or methanol (1-100 mM)
• Alternative solvents: DMSO, DMF, acetonitrile
• Dissolution: Dissolve dye with stirring or sonication
• Concentration check: Verify by UV-Vis (ε = 46,000 at 443 nm)
• Storage: Store at room temperature in amber bottle
• Stability: Months to years when protected from light

Working solution preparation:

• Laser applications: 0.1-10 mM in ethanol
• Fluorescence microscopy: 0.1-10 µM in buffer or medium
• Flow cytometry: 1-50 µM
• Sensing applications: 0.01-100 µM depending on sensitivity
• Dilute fresh: Prepare working solutions shortly before use

Important notes:

• Coumarin 343 has limited water solubility – use water-miscible organic solvents
• Protect solutions from prolonged light exposure
• pH can affect fluorescence – optimal pH 5-8
• For biological applications, keep organic solvent <1% final concentration

ChemContract supplies Coumarin 343 at 98% dye content, verified by HPLC and UV-Vis spectroscopy.

Quality control methods:

• HPLC analysis: Purity ≥98% by peak area
• UV-Vis spectroscopy: Dye content by absorption at 443 nm
• ¹H NMR spectroscopy: Structural confirmation
• ¹³C NMR spectroscopy: Complete structure verification
• Fluorescence spectroscopy: Emission spectrum verification
• Quantum yield: Measured relative to standards

Certificate of Analysis includes:

• Batch number and manufacturing date
• HPLC chromatogram with purity ≥98%
• UV-Vis absorption spectrum
• Fluorescence excitation and emission spectra
• ¹H NMR spectrum
• Quantum yield data (in ethanol)
• Appearance and solubility
• Storage recommendations

Coumarin 343 is relatively stable but should be protected from prolonged light exposure.

Storage conditions:

• Temperature: Room temperature (15-25°C) is acceptable
• Light: Store in amber bottle or protect from prolonged light
• Container: Tightly sealed to prevent moisture uptake
• Desiccation: Keep dry for long-term storage
• Shelf life: 36+ months when stored properly

Stock solution storage:

• Solvent: Ethanol or methanol solutions preferred
• Temperature: Room temperature in dark bottle
• Light protection: Amber bottle or foil-wrapped
• Stability: Months to years when protected from light
• Storage test: Check absorption spectrum periodically

Handling:

• Use clean, dry spatula for powder transfer
• Minimize light exposure during weighing
• Seal container tightly after use
• For maximum stability, can store at 2-8°C (not required)

Signs of degradation:

• Color change or fading
• Reduced fluorescence intensity
• Shifted absorption/emission maxima
• Additional peaks in HPLC

Yes, Coumarin 343 is an excellent laser dye with high efficiency in the blue-green spectral region.

Laser characteristics:

• Tuning range: 460-540 nm (typical)
• Peak efficiency: ~490-510 nm
• Quantum yield: High (0.6-0.8 in ethanol)
• Photostability: Good under pulsed excitation
• Triplet formation: Low, reducing triplet quenching

Typical laser setup:

• Dye concentration: 0.1-10 mM in ethanol
• Solvent: Ethanol (most common), methanol
• Pumping: Nitrogen laser (337 nm), frequency-tripled Nd:YAG (355 nm)
• Cavity: Standard dye laser cavity with brewster windows
• Circulation: Flowing dye solution recommended

Operating parameters:

• Pulse duration: ns to ps range
• Repetition rate: Up to several kHz
• Output power: mW to W range depending on pump power
• Beam quality: Excellent spatial and spectral quality

Advantages for laser use:

• High gain coefficient
• Broad tuning range
• Good photostability
• Low cost compared to other laser dyes
• Compatible with common pumping sources

We offer multiple pack sizes for research and industrial applications.

Available quantities (in stock):

• 100 mg – Initial studies and characterization
• 250 mg – Standard research quantity
• 500 mg – Extended research projects
• 1 g – Laser applications and high-volume use
• 5 g – Industrial and production quantities
• Custom quantities: Available for large-scale needs

Usage estimates:

• 100 mg makes 330 mL of 1 mM stock (sufficient for thousands of assays)
• 1 g sufficient for continuous laser operation for extended periods
• Typical laser dye solution: 1-10 mM (100 mg makes 33-330 mL)

Delivery times:

• Stock quantities: Ships within 24-48 hours
• Domestic USA: 2-3 business days (FedEx/UPS)
• International: 5-7 business days (DHL/FedEx)
• Custom quantities (>5g): 2-3 weeks

Packaging:

• Amber glass bottle for light protection
• Sealed under nitrogen (for large quantities)
• Standard shipping (room temperature stable)
• Certificate of Analysis included
• Safety Data Sheet included