Structure of 2',3'-O-isopropylideneguanosine dimethylsulfoxide solvate

Abstract

C₁₃H₁₇N₅O₅.C₂ H₆OS,M_r=401.23,orthorhombic,P2₁2₁ 2₁,grown from Me₂SO, a=10.749(2), b=13.219(2),c=14.056(2)Å, V = 1997·23 ų, Z =4, D_m =1.40, D_x=1.335Mgm^-3, λ(CuKa)= 1.5418 Å,μ =1.694mm^-1,F(OOO) = 848·00, T=293K, R=0.0538, wR=0.0634 for 2105 unique reflections with F> 3σ(F). The asymmetric unit con­tains one nucleoside molecule with a disordered solvent Me₂SO molecule. The geometry about the C(4')-C(5') bond is gauche-gauche. The guanosine base is in the anti conformation with the furanose ring having C(3'}cxo (E.) puckering. The bases do not show any stacking in contrast to other guanosine-containing structures. The crystal structure is stabilized by N-H···N and N-H···O hydrogen bonding.