1. What is Lifetime Ratio?

Definition: The Lifetime Ratio is the ratio of singlet state lifetime without quencher to singlet state lifetime with quencher of a given system.

Purpose: It helps in studying fluorescence quenching and understanding molecular interactions in photochemistry.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( ζ \) — Lifetime Ratio
• \( K_q \) — Quenching Constant (Hz)
• \( ζ_o \) — Singlet Lifetime without quencher (seconds)
• \( [Q] \) — Quencher Concentration

Explanation: The formula calculates how much the lifetime of the excited state is reduced in the presence of a quencher.

3. Importance of Lifetime Ratio

Details: This measurement is crucial in fluorescence spectroscopy for understanding quenching mechanisms and molecular interactions.

4. Using the Calculator

Tips: Enter the quenching constant in Hz, singlet lifetime in seconds, and quencher concentration. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is quenching in fluorescence?
A: Quenching refers to any process that decreases the fluorescence intensity of a given substance.

Q2: What's a typical quenching constant value?
A: The value varies widely depending on the system, typically ranging from 10⁶ to 10¹⁰ M^-1s^-1 for diffusion-controlled quenching.

Q3: How is singlet lifetime measured?
A: It's typically measured using time-resolved fluorescence spectroscopy techniques.

Q4: What affects the lifetime ratio?
A: Temperature, solvent viscosity, and the nature of the fluorophore-quencher interaction all affect the ratio.

Q5: What does a high lifetime ratio indicate?
A: A high ratio indicates strong quenching, meaning the quencher effectively reduces the excited state lifetime.