J. Appl. Cryst.の発刊に際して

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.

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

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.

A Short History Of...

Conformational stability, spectroscopic (FT-IR, FT-Raman and UV-Vis) analysis, NLO, NBO, FMO and Fukui function analysis of 4-hexylacetophenone by density functional theory.

The title complex, [CoCl(C5H13N)(C2H8N2)2]Cl2·H2O, comprises one chloridobis(ethyl­enediamine)(n-pentyl­amine)cobalt(III) cation, two chloride counter-anions and a water mol­ecule. The CoIII atom of the complex is hexa­coordinated by five N and one Cl atoms. The five N atoms are from two chelating ethyl­enediamine and one n-pentyl­amine ligands. Neighbouring cations and anions are connected by N—H⋯Cl and N—H⋯O hydrogen bonds to each other and also to the water mol­ecule.

https://journals.iucr.org/e/issues/2009/07/00/bq2142/bq2142.pdf

Chloridobis(ethyl-enediamine-κN,N')(n-pentyl-amine-κN)cobalt(III) dichloride monhydrate.

Construction of one-dimensional homochiral helical supramolecular stereoismers using chiral macrocyclic nickel(II) complexes as building blocks

In the title compound, C26H26O4, steric crowding of the Ph3C– group with the –CH(CO2Et)2 unit leads to a long C—C bond [1.585 (2) A]. One of the two ethyl groups is disordered over two sites in a 60:40 ratio.

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Diethyl 2-(triphenyl-meth-yl)malonate.

The title compound, [Ni(C8H5O4)(C16H36N4)]ClO4·H2O, has the NiII atom in a distorted octa­hedral geometry, surrounded by coordination by four N atoms of the 5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­decane ligand in a folded configuration, and two carboxyl­ate O atoms of the 2-carboxy­benzoate ligand in cis positions. The complex cation, the disordered perchlorate anion [occupancies 0.639 (8):0.361 (8)] and uncoordinated water mol­ecules engage in N—H⋯O and O—H⋯O hydrogen bonding, forming a layer structure parallel to (010).

https://journals.iucr.org/e/issues/2009/07/00/ng2586/ng2586.pdf

(2-Carboxy­benzoato-κ2O1,O1′)(5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­decane-κ4N)nickel(II) perchlorate monohydrate

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.

https://journals.iucr.org/e/issues/2010/11/00/bt5378/bt5378.pdf

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

C11H20O4, triclinic, P1 (no. 2), a = 6.014(2) Å, b = 9.566(3) Å, c = 10.135(4) Å, , = 96.669(6)°, + = 94.985(6)°, ' = 97.419(6)°, V = 571.2 Å, Z = 2, Rgt(F) = 0.053, wRref(F ) = 0.179, T = 298 K.

Min Zhang

Papers

Construction of one-dimensional homochiral helical supramolecular stereoismers using chiral macrocyclic nickel(II) complexes as building blocks

Diethyl 2-(triphenyl-meth-yl)malonate.

(2-Carboxybenzoato-κ2O1,O1′)(5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4N)nickel(II) perchlorate monohydrate

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

Crystal structure of 3,3-dihydroxymethyl- 1,6-dioxa-spiro[5.5]undecane, C11H20O4

Min Zhang

Papers

Construction of one-dimensional homochiral helical supramolecular stereoismers using chiral macrocyclic nickel(II) complexes as building blocks

Diethyl 2-(triphenyl-meth-yl)malonate.

(2-Carboxy­benzoato-κ2O1,O1′)(5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­decane-κ4N)nickel(II) perchlorate monohydrate

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

Crystal structure of 3,3-dihydroxymethyl- 1,6-dioxa-spiro[5.5]undecane, C11H20O4

(2-Carboxybenzoato-κ2O1,O1′)(5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4N)nickel(II) perchlorate monohydrate