Resonance and preresonance Raman spectra of nucleotides using ultraviolet lasers

✍ Scribed by Michel Pézolet; Tain-Jen Yu; Warner L. Peticolas

• Publisher: John Wiley and Sons
• Year: 1975
• Tongue: English
• Weight: 537 KB
• Volume: 3
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/jrs.1250030107

✦ Synopsis

Abstract

The Raman spectra of AMP and UMP have been taken as a function of the laser excitation wavelength at 5145 Å, 4880 Å, 4579 Å, 3638 Å, and 2572.5 Å (the first harmonic of 5145 Å). The Raman bands of adenine which decrease in intensity upon base stacking or base ordering are shown to derive their intensity largely from the ultraviolet absorption band at 2600 Å which also decreases in absorption strength upon base stacking or base ordering (hypochromism). These bands show a strong resonance Raman effect (RRE) with 2572.5 Å laser light. These results are in agreement with the suggestion of Tomlinson and Peticolas [1] that Raman hypochromism is largely derived from UV hypochromism. The hypochromic Raman band of uracil at 1230 cm^−1^ is shown to derive its intensity from the hypochromic UV band at 2050 Å. None of the bands of uracil appear to show RRE when 2572.5 Å laser radiation is used.

One or two Raman bands in adenine which are not strongly hypochromic show RRE at 2572.5 Å. These bands appear to come from vibrations which have Raman tensors that derive their intensity from higher UV bands as well as the 2600 Å band.