1 a. Explain why compound with conjugated systems can fluoresce. b. Why is tryptophan more fluorescent...

Question

Question

1

a. Explain why compound with conjugated systems can fluoresce.

b. Why is tryptophan more fluorescent than tyrosine and phenylalanine?

science chemistry

Answer 1

Answer #1

Solution:

a) In the conjugated systems, the ground states and excited states of the electrons are closer in energy than for

non-conjugated systems. Therefore, a lower energy light is needed to excite electrons in conjugated systems, which means that

lower energy light is absorbed by conjugated systems. Hence, conjugated systems can fluoresce.

b) Tryptophan is significantly more fluorescent than tyrosine and phenylalanine because of its greater absorptivity, higher

quantum yield, and resonance energy transfer than tyrosine and phenylalanine. Its fluorescent properties are solvent dependent,

therefore, the spectrum shifts to shorter wavelengths and increases in intensity as the polarity of the solvent decreases.

Answer 2

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