Open AccessBase Crystallization and Base Stacking in Water
Author(s) -
MARTEL Peter
Publication year - 1979
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1979.tb13031.x
Subject(s) - crystallite , stacking , neutron diffraction , diffraction , crystallization , scattering , crystallography , molar concentration , base (topology) , neutron scattering , materials science , chemistry , crystal structure , organic chemistry , physics , optics , mathematics , mathematical analysis
2 H 2 O solutions of 6‐methylpurine and N 6 , N 9 ‐dimethyladenine have been examined by neutron diffraction. Comparison of the scattering from various molar solutions of 6‐methylpurine with the scattering from its crystalline precipitates indicated base stacking in solution with a separation of ∼ 0.34 nm. In particular at 1.75 M the effective stacking number in 6‐methylpurine, as seen by neutron diffraction, was found to be approximately nine. Attempts to observe similar scattering from N 6 , N 9 ‐dimethyladenine were hampered because solutions with a molarity ≳ 0.02 tended to form filamentary crystallites as a function of time. An analysis of the autocatalytic reaction involved in the formation of these dendrites is given. The rate constant is found to be 2.12 ± 0.05 M −1 h −1 . By comparing the diffraction from wet and dry crystallites it is concluded that hydrophilic interactions mediate the aggregation of both bases in water.