Red shift
Step 1: Understanding DNA denaturation. - DNA denaturation refers to the disruption of hydrogen bonds between base pairs, leading to strand separation. - This process results in an increase in UV absorbance due to unstacking of bases.
Step 2: Explanation of incorrect options. - (A) Bathochromic shift: Refers to a shift to longer wavelengths (red shift) but is not related to DNA denaturation. - (B) Blue shift: Refers to a shift to shorter wavelengths, which does not occur in DNA denaturation. - (D) Red shift: Similar to a bathochromic shift but does not describe the absorbance increase seen in denaturation.
Step 3: Selecting the correct option. Since DNA denaturation leads to an increase in UV absorbance, the correct term is hyperchromic shift. Hence, the correct answer is (C) Hyperchromic shift.
The UV-visible spectrum of [Ni(en)\(_3\)]\(^{2+}\) (en = ethylenediamine) shows absorbance maxima at 11200 cm\(^{-1}\), 18350 cm\(^{-1}\), and 29000 cm\(^{-1}\).
[Given: Atomic number of Ni = 28] The correct match(es) between absorbance maximum and electronic transition is/are
Compound K displayed a strong band at 1680 cm−1 in its IR spectrum. Its 1H-NMR spectral data are as follows:
δ (ppm):
7.30 (d, J = 7.2 Hz, 2H)
6.80 (d, J = 7.2 Hz, 2H)
3.80 (septet, J = 7.0 Hz, 1H)
2.20 (s, 3H)
1.90 (d, J = 7.0 Hz, 6H)
The correct structure of compound K is:
The 1H NMR spectrum of the given iridium complex at room temperature gave a single signal at 2.6 ppm, and its 31P NMR spectrum gave a single signal at 23.0 ppm. When the spectra were recorded at lower temperatures, both these signals split into a complex pattern. The intra-molecular dynamic processes shown by this molecule are:
A closed-loop system has the characteristic equation given by: $ s^3 + k s^2 + (k+2) s + 3 = 0 $.
For the system to be stable, the value of $ k $ is: