1-(β-D-Erythrofuranos­yl)cytidine (β-erythrocytidine)

1-(β-D-Erythrofuranosyl)cytidine, C₈H₁₁N₃O₄, (I), a derivative of β-cytidine, (II), lacks an exocyclic hydroxy­methyl (–CH₂OH) substituent at C4′ and crystallizes in a global conformation different from that observed for (II). In (I), the β-D-erythrofuranosyl ring assumes an E₃ conformation (C3′-exo; S, i.e. south), and the N-glycoside bond conformation is syn. In contrast, (II) contains a β-D-ribofuranosyl ring in a ³T₂ conformation (N, i.e. north) and an anti-N-glycoside linkage. These crystallographic properties mimic those found in aqueous solution by NMR with respect to furan­ose conformation. Removal of the –CH₂OH group thus affects the global conformation of the aldofuranosyl ring. These results provide further support for S/syn–anti and N/anti correlations in pyrimidine nucleosides. The crystal structure of (I) was determined at 200 K.

Poly[[diaqua­(N,N-dimethyl­formamide-[kappa]O)manganese(II)]-[mu]₃-sulfato]

In the title complex, [Mn(SO₄)(C₃H₇NO)(H₂O)₂]_n, each Mn^II ion has a distorted octa­hedral geometry formed by three O atoms of three different sulfate groups, one O atom of a dimethyl­formamide ligand and two water mol­ecules. The sulfate groups act as tridentate bridging ligands connecting the Mn^II ions into a two-dimensional layer structure which can be regraded as a 4.8² network.