Molecular recognition motifs in cytidinium and 2'-deoxycytidinium salts with composite anions.
In the crystal structures of N3-protonated cytidinium and 2'-deoxycytidinium salts with composite XYn anions capable of accepting hydrogen bonds through their Y atoms, the dominating motif of cytosinium...anion interactions consists of a pair of hydrogen bonds donated from the N3+ -H protonation site and from the exoamino N4-H41 group cis to N3, and accepted by two Y centers of one anion. This multipoint recognition pattern is stable and robust and thus can be classified as a supramolecular synthon. In a broader group of N3-protonated, N1-substituted cytosinium salts with composite anions it occurs with 70% frequency. The C5 side of the cytosine ring mimics the N3+ -H type synthon and shows a propensity to form an analogous motif in which a C5-H5...Y hydrogen bond replaces the strong N3+ -H...Y interaction. Since the C-H...Y bond is much weaker, the secondary motif shows higher deformability and is less frequent (44%).
Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań.
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M
Gilski
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M
Jaskólski
D000838:Anions / Q000737:chemistry*; D002412:Cations / Q000737:chemistry*; D003461:Crystallography; D003562:Cytidine / Q000737:chemistry*; D003841:Deoxycytidine / Q000737:chemistry*; D003845:Deoxycytosine Nucleotides / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular
D000838:Anions; D002412:Cations; D003845:Deoxycytosine Nucleotides; D003841:Deoxycytidine; D003562:Cytidine