1. An anti-parallel triple helix motif with oligodeoxynucleotidescontaining 2'-deoxyguanosine and 7-deaza-2'-deoxy xanthosine
2. 7-Desaza-Isostere von 2′-Desoxyxanthosin und 2′-Desoxyspongosin — Synthese via Glycosylierung von 2,4-Dichlor-7H-pyrrolo[2,3-d]pyrimidin
3. Crystal data for 1⋅2 H2O (C11H17N4O7; c7Xd): Mr=303.28, crystal dimensions 0.42×0.30×0.24 mm, monoclinic, space group P21, a=4.891(2), b=17.746(4), c=15.467(4) Å, β=92.53(2)°, V=1341.3(6)Å3, Z=4, ρcalcd=1.502 Mg m−3, θmax=25.01°, μ=0.126 mm−1 (MoKα with λ=0.71073 Å), 2θ/ω scans, T=293(2) K, 5418 measured reflections, 4698 independent reflections; 4698 reflections used for refinement, of which 4271 had I>2σ(I), Tmin=0.1333, Tmax=0.1778. Data were collected on a Siemens P4 diffractometer. The structure was determined by direct methods (SHELXS97: G. M. Sheldrick, Program for the Solution of Crystal Structures, Universität Göttingen, 1997). Refinement on F 2 was performed with SHELXL (
4. G. M. Sheldrick, Program for the Refinement of Crystal Structures, Universität Göttingen, 1997), 404 free parameters, H atoms were treated by a mixture of independent and constrained refinement, R=0.0463, wR=0.1609, residual electron density min./max.=−0.299/0.228 e Å−3. CCDC 169203 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html (or from the Cambridge Crystallographic Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-033; or deposit@ccdc.cam.ac.uk).
5. Abbreviations and Symbols for the Description of Conformations of Polynucleotide Chains. Recommendations 1982