organic compounds
Open access
The title compound, C16H19NO5, which was synthesized from p-methoxycinnamic acid, has intramolecular O—HO and N—HO hydrogen-bonding interactions. In the crystal, molecules are linked by weak C—HO hydrogen bonds and aromatic π–π stacking interactions [minimum ring centroid–centroid separation = 3.790 (1) Å].
metal-organic compounds
Open access
In the title compound, {[Ho2(C6H4NO3)2(C2O4)2(H2O)2]·2H2O}n, the HoIII atom is coordinated by three O atoms from three 5-hydroxynicotinate ligands, four O atoms from two oxalate ligands, each lying on an inversion center, and one water molecule in a distorted square-antiprismatic geometry. The 5-hydroxynicotinate ligand is protonated at the N atom and deprotonated at the hydroxy group. The HoIII atoms are bridged by the carboxylate and phenolate O atoms, forming a three-dimensional framework. N—HO and O—HO hydrogen bonds, as well as π–π interactions between the pyridine rings [centroid–centroid distance = 3.794 (2) Å], are observed.
organic compounds
Open access
The title compound, C51H78N4O12, is a derivative of rapamycin, a triene macrolide antibiotic molecule isolated from Streptomyces hygroscopicus. The macrocyclic ring structure has 15 chiral centres, with one of the substituent hydroxy groups giving an intramolecular hydrogen bond to a ketone O-atom acceptor. The molecules also form intermolecular hydroxy–ketone O—HO hydrogen-bonding associations, giving one-dimensional chains extending along (010). The crystal has 108 Å3 solvent-accessible voids.