RESUMEN
The title compound, C32H32O8*3C2H4Cl2, illustrates how tetrabenzo-24-crown-8 may be solvated by a common solvent-extraction diluent, 1,2-dichloroethane (DCE). Two molecules of DCE occupy the crown cavity, forming weak hydrogen bonds to the ether O atoms and the crown arene rings, while the crown adopts its most commonly observed binding conformation. The asymmetric unit is composed of two molecules of tetrabenzo-24-crown-8 and six molecules of DCE.
RESUMEN
Tribenzo-18-crown-6 binds two acetonitrile ligands, i.e. C(24)H(24)O(6) x 2C(2)H(3)N, one to each face of the crown ring. The crown conformation is relatively low in energy, but does not appear optimized for cation binding. Few significant intermolecular interactions are observed.
RESUMEN
The title compound, C(9)H(9)Cl(3), is being used as a platform for new tripodal receptors. Two molecules make up the asymmetric unit; weak intermolecular hydrogen bonding is observed between methylene H atoms and the chlorine of an adjacent molecule. There are also C-H.pi interactions.
RESUMEN
When complexed by tetrabenzo-24-crown-8, the cesium ion can accommodate unprecedented ligation. The structures of the following complexes are presented. [Cs(tetrabenzo-24-crown-8)(eta 1-NCMe)2(eta 2-NCMe)][NO3] (1): triclinic P1, a = 12.0119(14) A, b = 13.3680(15) A, c = 13.7859(12) A, alpha = 89.124(8) degrees, beta = 66.928(9) degrees, gamma = 71.536(10) degrees, V = 1916.7(4) A3, Z = 2. [Cs(tetrabenzo-24-crown-8)(eta 1-NCMe)2(eta 2-CH2Cl2)][NO3] (2): triclinic, P1, a = 12.295(3) A, b = 13.295(3) A, c = 13.782(3) A, alpha = 89.105(17) degrees, beta = 66.096(18) degrees, gamma = 71.980(19) degrees, V = 1929.5(8) A3, Z = 2. These structures are the first reported examples of linear eta 2-acetonitrile coordination to any metal ion and the first structures illustrating eta 2-acetonitrile and dichloromethane ligation to an alkali metal ion. Possible steric and electronic origins of these unusual metal-ligand interactions are discussed.
RESUMEN
This study was designed to delineate the course of sexual satiation in prairie voles (Microtus ochrogaster). Fourteen male-female pairs were allowed to copulate freely for 24 hr under continuous observation. Copulations occurred predominantly during the first few hours and decreased in frequency thereafter. The mean number of ejaculations per pair was 5.6 (range, 2-9). Two thirds of the ejaculations occurred during the first 3 hr, and over 90% took place within the first 7 hr after the first intromission. No ejaculations were observed during the last 8 hr. These results suggest that male capacity to deliver ejaculations to a female is limited and that direct observations reveal a more limited capacity than observations made with time-lapse videotape.