Question

)Ethylene absorbs strongly at 175 nm in far UV region. The value changes to atching a double bond to it. The shift in wavelength corresponds to. a. Bathochromic shift b. Hypsochromic shift c. Hyperchromic shift​

Answer 1

Bathochromic shift

Explanation:

• Bathochromic shift , also known as the red shift is the shift of absorption maxima to a longer wavelength.
• It can be achieved in different ways. One of them is by conjugation of two chromophores.
• In the given question , ethylene absorbs strongly at 175 (ϵ  15000) nm in the far UV region but when two double bonds are brought in conjugation, similar to that in butadiene, the π- π* transition undergoes a bathochromic shift along with hyperchromic effect and butadiene now absorbs at 2701 nm . This shows a shift of wavelength to a longer wavelength.
• Such a shift is known as Bathochromic shift.
• Answer is (a).