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Cover Picture: Long‐Wavelength Fluorescence from 2‐Aminopurine‐Nucleobase Dimers in DNA (ChemPhysChem 8/2008)
Author(s) -
Bonnist Eleanor Y. M.,
Jones Anita C.
Publication year - 2008
Publication title -
chemphyschem
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200890030
Subject(s) - nucleobase , fluorescence , wavelength , chemistry , excitation , dna , excitation wavelength , crystallography , photochemistry , molecular physics , materials science , optoelectronics , optics , physics , biochemistry , quantum mechanics
The cover picture illustrates the dual fluorescence when 2‐aminopurine, a fluorescent analogue of adenine, is substituted for a natural base in DNA. Excitation at 300 nm produces the well‐known 370 nm emission band, but excitation at 360 nm produces a second, red‐shifted emission band at 450 nm. The long‐wavelength emission is attributed to conformational states of the duplex in which 2‐aminopurine forms a highly overlapped, π‐stacked heterodimer with an adjacent base. It is proposed by Bonnist and Jones (page 1121) that the essential difference between the short‐wavelength and long‐wavelength emitting conformations is the size of the helical twist between 2‐aminopurine and its flanking bases.