A STUDY OF THE SELF-ASSEMBLY OF 2'-DEOXYGUANOSINE 3'5'-CYCLIC MONOPHOSPHATE, D(CGP), BY CD AND X-RAY-DIFFRACTION

2'-Deoxyguanosine 3':5'-cyclic monophosphate forms in water cholesteri c and hexagonal columnar mesophases. The polymorphic behaviour and the structural building blocks of the liquid crystalline phases, as deter mined by optical microscopy, CD spectroscopy and X-ray diffraction, ar e comparable to those found with all the deoxyguanylates investigated so far (in particular with deoxuguanosine 5'- and 3'-monophosphate). T he present results show that the formation of a stacked array of plana r G-tetramers, a necessary condition for the existence of the columnar mesophases, occurs even in the absence of hydrogen bonding groups lin king the molecules along the length of the columns.