𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Calculations of the circular dichroism of double-helical nucleic acids. II. Effects involving n → π* transitions

✍ Scribed by David S. Studdert; Robert C. Davis

Publisher
Wiley (John Wiley & Sons)
Year
1974
Tongue
English
Weight
725 KB
Volume
13
Category
Article
ISSN
0006-3525

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The circular dichroism of double‐helical nucleic acids was calculated as a function of geometry, including terms involving n → π* transitions. The “nonbonding” n or σ orbitals were of the azine type, delocalized, but concentrated at the nitrogen atoms of the purines and pyrimidines. Dynamic coupling of the magnetic moments of the n → π* transitions with the electric moments of π → π* transitions generated important terms. Mixing of electric dipole character into n → π* transitions by the static electric field perturbation of the molecule is of lesser importance. The largest contributions of n → π* transitions to the circular dichroism of double‐helical nucleic acids are comparable in magnitude to the sum of π → π* terms only for geometries where the circular dichroism is weak. Using both n → π* and π → π* contributions one is able to match experimental and calculated circular dichroism spectra for DNA's over a much wider range of conditions than was possible previously.

📜 SIMILAR VOLUMES

Calculations of the circular dichroism o
Calculations of the circular dichroism of double-helical nucleic acids. I. Effects involving π → π* transitions
✍ David S. Studdert; Robert C. Davis 📂 Article 📅 1974 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 657 KB

## Abstract The circular dichroism of double‐helical nucleic acids was calculated as a function of geometry using the theory of Tinoco and Johnson. This theory does not include contributions of near ultraviolet transitions that are not π → π\* in nature. The calculated circular dichroism shows a st

Calculation of the circular dichroism of
Calculation of the circular dichroism of double-helical nucleic acids. III. Dependence of the results on the choice of wave functions for purines and pyrimidines
✍ David S. Studdert; Robert C. Davis 📂 Article 📅 1974 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 559 KB

## Abstract The circular dichroism of double‐helical nucleic acids was calculated using three different sets of wave functions for the purine and pyrimidine chromophores. Different wave functions give qualitatively the same types of spectra. Quantitatively, the differences are very substantial. How

Effect of side chains on the conformatio
Effect of side chains on the conformational energy and rotational strength of n–π* transition for some α-helical poly-α-amino acids
✍ John N. Vournakis; Johnson F. Yan; Harold A. Scheraga 📂 Article 📅 1969 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 59 KB 👁 1 views

On page 1533, in the last term of eq. (2), (alm[O) should be (alml0). On page 1538, in line 3 of the Results section, R,,\* should be Rn,\*; in the next line, RB should also be Rn,\*, and the first "in" should be "is.