organic compounds
The structure of the title compound (systematic name: 2-{2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetoxy}acetic acid monohydrate, C21H18ClNO6·H2O) contains one-dimensional infinite hydrogen-bonded chains. Molecules of acemetacin, a nonsteroidal anti-inflammatory drug, and water are linked by three independent O—HO bonds. The central unit in each chain consists of a sequence of alternating centrosymmetric R44(12) and R44(18) rings, which are edge-fused. Each ring links two acemetacin and two water molecules. A comparison with seven related structures reveals that molecules of acemetacin, indomethacin and their analogues can adopt two principal conformations.
organic compounds
N-HO bonding in a form of 5-butyl-5-ethylbarbituric acid (systematic name: 5-butyl-5-ethyl-1,3-diazinane-2,4,6-trione), C10H16N2O3, produces two distinct one-dimensional motifs, viz. tape and ladder. Both are different from the ribbon chain motif observed in two previously reported polymorphs of the same compound.