metal-organic compounds
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The title salt, [K(C18H36N2O6)][Co(CO)4], is an example of a classical carbonylmetalate. The asymmetric unit contains one cation and one tetrahedral anion, both in general positions. Based on comparison of the four carbonyl C-O bond lengths and C-Co-C angles, the anion is unperturbed by the cation, which is normal for an alkali metal fully encased by a cryptand cage.
metal-organic compounds
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The title complex, [Ta(η4-C8H8)(η8-C8H8)I], lies across a crystallographic mirror plane that includes the TaV atom and the iodide ligand. One cyclooctatetraene (cot) ring is η4-coordinating and is bisected by the mirror plane. The fold angle between the plane of the coordinating butadiene portion and the middle plane of the ring is 27.4 (4)°. An additional minor fold angle of 9.3 (7)° exists between the final plane in the ring and the middle plane. The other cot ring is η8-coordinating and is also cut by the mirror plane. In this case, the ring is disordered over the mirror plane, and one position is modeled with appropriate restraints and constraints with respect to distances, angles and displacement parameters (the second position is generated by symmetry). This ring is nearly planar, with an r.m.s. deviation of only 0.05 Å when all eight C atoms are included in the calculation. Pairs of intermolecular η8-cot rings are parallel stacked and slightly off center, with a centroid–centroid distance of 3.652 Å. No other significant intermolecular interactions are observed. The compound is of interest as the first structurally characterized mixed halogen–cot complex of the group 5 metals and contains the longest terminal Ta—I distance [3.0107 (5) Å] reported to date.
research communications
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The first reported structure of a cobalt complex containing an η6-anthracene ligand is presented. The anthracene ligand is nearly flat and coordinates the metal asymmetrically, such that the ring junction carbon atoms are slightly further from the cobalt center than are the other four.
research communications
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Molecules of two related 1,2-amino alcohols are linked via N—HO=S hydrogen bonds, forming chains along [100] for the first compound and along [010] for the second compound.
organic compounds
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The asymmetric unit of the title compound, 2C23H33NO2S·H2O, contains one organic molecule in a general position and one co-crystallized water molecule on a crystallographic twofold axis. Each water molecule serves as a hydrogen-bond donor to a pair of S=O acceptors on symmetry-related molecules. Thus, each trio of molecules forms one title formula unit. These groupings are further connected along [010] via weak non-classical C—HO hydrogen bonds.