Xian-You Yuan

Bio: Xian-You Yuan is an academic researcher from Hunan University of Science and Engineering. The author has contributed to research in topics: Crystal structure & Carboxylic acid. The author has an hindex of 5, co-authored 42 publications receiving 76 citations.

(5-n-Heptyl-2-hydroxymethyl-1,3-dioxan-2-yl)methanol.

Abstract: In the title compound, C13H26O4, the dioxane rings adopts a chair conformation; the n-heptyl chain occupies an equatorial position. In the crystal, mol­ecules are connected by O—H⋯O hydrogen bonds into a zigzag chain running along the a axis, giving rise to a herringbone pattern. There are two independent mol­ecules in the asymmetric unit.

Crystal structure of 5-methyl-2-phenyl-1,3-dioxane-5-carboxylic acid, C12H14O4

Abstract: Abstract C12H14O4, monoclinic, C2/c, a = 32.6674(8) Å, b = 6.0061(2) Å, c = 23.2786(6) Å, α = 90°, β = 103.368(2)°, γ = 90°, V = 4443.6(2) Å3, Z = 16, Rgt(F) = 0.0459, wRref(F2) = 0.1412, T = 298(2) K.

Synthesis and crystal structures of three isophthalato-bridged macrocyclic nickel(II) complexes

Abstract: Three dinuclear isophthalato-bridged nickel(II) complexes formulated as [Ni(rac-L)]2(μ-IPA)(ClO4)2 (1), [Ni(RR-L)]2(μ-IPA)(ClO4)2 (2) and [Ni(SS-L)]2(μ-IPA)(ClO4)2 (3) (L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyc-lotetradecane, IPA = isophthalic acid) have been isolated and characterized. Single crystal X-ray diffraction analyses revealed that the Ni(II) atoms have six-coordinated distorted octahedral environments, and the isophthalato ligand bridges two Ni(II) centres in a bis bidentate fashion to form dimers in all three complexes. The monomers of {[Ni(SS-L)]2(μ-IPA)} 2+ are connected through intermolecular hydrogen bonds to generate one-dimensional left-handed helical chains in complex 3. The homochiral natures of complexes 2and3have been confirmed by CD spectroscopy.

Crystal structure of (2-(2-chlorophenyl)-5-methyl-1,3-dioxan-5-yl)methanol, C12H15ClO3

Abstract: Abstract C12H15ClO3, monoclinic, P21/c (no. 14), a = 10.0231(14) Å, b = 10.7318(16) Å, c = 11.2419(17) Å, β = 106.637(7)°, V = 1158.6(3) Å3, Z = 4, Rgt(F) = 0.0493, wRref(F2) = 0.1879, T = 296(2) K.

Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations

Abstract: This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 A (0.084 A for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 A either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect.

A Short History Of...

Abstract: There are very few people who have lived the allotted time but have an interesting biography, and there are very few congregations but have a very profitable history. The church at Leiper’s Fork, now known as Hillsboro, TN, has a most interesting history. There are few, if any, who know the history of their congregation. It seems that it would be encouraging to the congregation if its history would be kept fresh in the minds of its members.

Group 12 Metal Complexes of an 18-Membered N2O2S2 Macrocycle Incorporating Two Pyridines: First Examples of an Infinite Mercury(I) Complex and a Dumbbell-Shaped Heteronuclear Complex with a Macrocyclic Ligand

Abstract: Homo- and heteronuclear group 12 metal (Zn2+, Cd2+, and Hg2+) complexes 1–6 containing a newly designed 18-membered N2O2S2 macrocycle incorporating two pyridine subunits (L) were prepared and structurally characterized. The individual complexes isolated exhibit unusual stoichiometries, geometries, oxidation states, and structural topologies and include an infinite mercurous complex and a heteronuclear dumbbell-shaped complex. Both the Zn(II) complex [Zn(L)][ZnBr4] (1) and the Cd(II) complex [Cd(L)Br2] (2) are mononuclear, with the metal ion located inside the macrocyclic cavity. The six-coordinated Zn(II) center in 1 adopts an octahedral geometry and is shielded from the anion and solvent by the strongly bound macrocycle. The Cd(II) center in 2 is seven-coordinate, being bound equatorially to two N donors, two O donors, and a S donor from the macrocycle and axially to two bromide ions on opposite sides of the macrocyclic plane, adopting a pentagonal-bipyramidal geometry. In the Hg(II) complexations, the c...