1,15‐Penta­decane­diol

In the title compound, C₁₅H₃₂O₂, one of the terminal hydroxyl groups has a gauche conformation with respect to the hydro­carbon skeleton, while the other is trans. The mol­ecules lie parallel to the longest axis and form layers similar to those of the smectic A structure of liquid crystals. These features are similar to those of the homologues with an odd number of C atoms, but different from those with an even number.     

1,17‐Hepta­decane­diol

In the title compound, C₁₇H₃₆O₂, one of the hydroxyl groups has a gauche conformation with respect to the hydro­carbon skeleton, which is all‐trans, whereas the other has a trans conformation. The molecular shape is rod‐like and the compound has a rotator phase in which mol­ecules are assured greater motional freedom, as in liquid crystals. In addition, the mol­ecules arranged along the longest axis, b, form layers which are very similar to those of the smectic A liquid crystals.     

Pentane and tetra­hydro­furan solvates of trans‐di­chloro­bis­[1,2‐ethane­diyl­bis­(di­phenyl­phos­phine)‐P,P′]­molybdenum(II)

trans‐[MoCl₂(dppe)₂] [dppe is 1,2‐ethane­diyl­bis­(di­phenyl­phos­phine), C₂₆H₂₄P₂] was obtained as a side product from the reaction of trans‐[Mo(dppe)₂(N₂)₂] with Cp*GeCl to give the germyl­yne complex trans‐[Cl(dppe)₂Mo[triple‐bond]Ge(η¹‐Cp*)]. The crystal structures of the hemi­pentane (0.5C₅H₁₂) and di­tetra­hydro­furan (2C₄H₈O) solvates of trans‐[MoCl₂(dppe)₂], (IIIa) and (IIIb), respectively, have been determined.     

Two optically active iso­quinoline derivatives

In the two title optically active tetra­hydro­iso­quinoline derivatives, namely 3‐hydroxy­methyl‐4‐phenyl‐1,2,3,4‐tetra­hydro­isoquinolin‐2‐ium bromide methanol hemisolvate, C₁₆H₁₈NO⁺·Br^?·0.5CH₃OH, (IIb), and 2‐formyl‐3‐hydroxy­methyl‐4‐phenyl‐1,2,3,4‐tetra­hydro­iso­quinoline, C₁₇H₁₇NO₂, (III), the absolute configurations have been confirmed as 3R,4R by structure refinement using Bijvoet‐pair reflections. The hydroxy­methyl and phenyl groups in (IIb) are oriented in equatorial and pseudo‐equatorial positions, respectively, whereas in (III), the corresponding groups are in axial and pseudo‐axial positions, respectively; the hydroxy­methyl and phenyl groups are trans with respect to one another in both structures. The heterocyclic rings in (IIb) and (III) adopt envelope conformations inverted with respect to each other. In both structures, the mol­ecules are linked through hydrogen bonds.     

cis,cis‐Ceratospong­amide N,N‐di­methyl­acet­amide hemisolvate in the presence of twinning

Ceratospong­amide (CS) is a potent inhibitor of secreted phospho­lipase A₂, and cis,cis and trans,trans isomers, related with respect to the two proline amide bonds, are known. Crystals of cis,cis‐CS were grown from N,N‐di­methyl­acet­amide solution, giving the title compound, the cyclic ester of isoleucyl­oxazolinyl­phenyl­alanyl­prolyl­thia­zolyl­phenyl­alanyl­pro­line [cyclo(‐Ile–Oxz–Phe–Pro–Thz–Phe–Pro‐)] N,N‐di­methyl­acet­amide hemisolvate, C₄₁H₄₉N₇O₆S·0.5C₄H₉NO. The structure is the third example of cis,cis‐CS to be investigated and comprises twinned crystals, in which the a and b axes are interchanged. The ratio of co‐existing twin crystals is approximately 50%. The peptide has a `saddle‐like' structure and is very similar to previously reported structures of cis,cis‐CS, which implies that the structure of cis,cis‐CS is very stable in spite of differences in crystallization conditions.     

One‐dimensional polymeric chain structure of bis­(aniline)­di­thio­cyanato­cadmium(II)

In the title compound, catena‐poly­[[bis­(aniline‐N)cadmium(II)]‐di‐μ‐thio­cyanato‐S:N;N:S], [Cd­(SCN)₂­(C₆H₇N)₂], the Cd^II atom lies on an inversion centre and is in a distorted octahedral geometry. The coordination sphere contains two thio­cyanate (SCN) S atoms, two iso­thio­cyanate (NCS) N atoms and two aniline N atoms. The six‐coordinated Cd atoms run parallel to the b axis and are doubly bridged with neighbouring Cd atoms by SCN and NCS ligands. Thus, this complex has a one‐dimensional coordination polymeric chain structure in which the aniline ligand is in the trans conformation.     

Penta­aqua­oxovanadium(IV) bis(trifluoro­methane­sulfonate)

The structure of the penta­aqua­oxo­vanadium(IV) ion in a salt with singly charged counter‐ions is presented. In [VO(H₂O)₅](CF₃SO₃)₂, the six‐coordinate V atom is coordinated to the oxo group with a short bond [1.577 (2) Å]. The equatorial V—O bond lengths are 2.0262 (18) and 2.0277 (17) Å. The aqua ligand trans to the oxo group is subject to its trans influence, which leads to a somewhat longer V—O bond [2.175 (2) Å]. In the structure, the cation and both anions are situated on crystallographic mirror planes. The cation and anions engage in a number of relatively long hydrogen bonds [2.725 (2)–2.834 (2) Å].     

Two thia­zolino­[2,3-a]­iso­quinolinone S-oxides

The structures of two racemic thia­zolino­[2,3-a]­isoquinolinone S-oxides, i.e. 8,9-di­methoxy-2,3,5,6-tetra­hydro-10bH-thia­zolo­[2,3-a]­isoquinolin-3-one 1-oxide [C₁₃H₁₅NO₄S, (IIa)] and 8,9-di­methoxy-10b-methyl-2,3,5,6-tetra­hydro-10bH-thia­zolo­[2,3-a]­isoquinolin-3-one 1-oxide [C₁₄H₁₇NO₄S, (IIb)], are described. The thia­zolinone ring in (IIa) exists in an envelope conformation, while in (IIb), it assumes a half-chair conformation. In (IIa) and (IIb), the six-membered heterocyclic ring adopts an envelope conformation. The O atom at sulfur is oriented in a pseudo-axial position, whereas the H atom in (IIa) and the methyl group in (IIb), linked to the stereogenic C centre, occupy a bisectional position with respect to the partially saturated pyridine ring and a pseudo-axial position with respect to the thia­zolinone ring. In both structures, the S=O group and the substituent at the stereogenic C centre are trans with respect to one another. Intermolecular C—H⋯O hydrogen bonds are observed in the crystal lattice of (IIa) and (IIb).     

trans‐Bis­[N‐(2‐hydroxy­ethyl)­ethyl­ene­di­amine‐κ2N,N′]­bis­(iso­thio­cyanato‐κN)­nickel(II)

The crystal structure of the title compound, [Ni(NCS)₂(C₄H₁₂N₂O)₂], has two crystallographically independent half‐mol­ecules in the asymmetric unit, with each Ni atom residing on a centre of symmetry. The two mol­ecules exhibit similar coordination geometry but display differences with regard to other structural features. Each Ni^II centre is octahedrally coordinated by two mutually trans chelating hydroxy­ethyl­ethyl­ene­di­amine ligands and two mutually trans iso­thio­cyanate ions. The two independent mol­ecules form chains through different types of non‐covalent interactions. In the case of one of the mol­ecules, only NCS and free OH groups participate in hydrogen bonding, while in the chain based on the second mol­ecule, the NCS, NH, NH₂ and free OH groups are involved in intermolecular hydrogen bonding. The two chains interact with one another through hydrogen bonding, forming planar sheets. The third packing direction is mediated only by van der Waals interactions.     

Cyano­cobalt(III) complexes of penta‐ and tetra­dentate‐coordinated macrocyclic hexa­amines

The pendent‐arm macrocyclic hexa­amine trans‐6,13‐dimethyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐diamine (L) may coordinate in tetra‐, penta‐ or hexa­dentate modes, depending on the metal ion and the synthetic procedure. We report here the crystal structures of two pseudo‐octa­hedral cobalt(III) complexes of L, namely sodium trans‐cyano­(trans‐6,13‐dimethyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐diamine)cobalt(III) triperchlorate, Na[Co(CN)(C₁₃H₃₀N₆)](ClO₄)₃ or Na{trans‐[CoL(CN)]}(ClO₄)₃, (I), where L is coordinated as a penta­dentate ligand, and trans‐dicyano­(trans‐6,13‐dimethyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐diamine)cobalt(III) trans‐dicyano­(trans‐6,13‐dimethyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐diaminium)cobalt(III) tetra­perchlorate tetra­hydrate, [Co(CN)₂(C₁₄H₃₂N₆)][Co(CN)₂(C₁₄H₃₀N₆)](ClO₄)₄·4H₂O or trans‐[CoL(CN)₂]trans‐[Co(H₂L)(CN)₂](ClO₄)₄·4H₂O, (II), where the ligand binds in a tetra­dentate mode, with the remaining coordination sites being filled by C‐­bound cyano ligands. In (I), the secondary amine Co—N bond lengths lie within the range 1.944 (3)–1.969 (3) Å, while the trans influence of the cyano ligand lengthens the Co—N bond length of the coordinated primary amine [Co—N = 1.986 (3) Å]. The Co—CN bond length is 1.899 (3) Å. The complex cations in (II) are each located on centres of symmetry. The Co—N bond lengths in both cations are somewhat longer than in (I) and span a narrow range [1.972 (3)–1.982 (3) Å]. The two independent Co—CN bond lengths are similar [1.918 (4) and 1.926 (4) Å] but significantly longer than in the structure of (I), again a consequence of the trans influence of each cyano ligand.     

The charge‐transfer complex trans‐STB–TCNQF4

In the crystal structure of the title charge‐transfer complex, namely trans‐stilbene–2,2′‐(2,3,5,6‐tetra­fluoro­benzene‐1,4‐diyl­idene)­propane­di­nitrile (1/1) (trans‐STB–TCNQF₄), C₁₄H₁₂·C₁₂F₄N₄, the planar STB and TCNQF₄ mol­ecules are stacked alternately. The structure is not isostructural with that of STB–TCNQ. No anomaly was found in the displacement parameters of any atoms, while the bond length of the central C=C moiety was shorter than the corresponding bond in ethyl­ene. This suggests that the central C=C moiety of the STB mol­ecule vibrates with a large amplitude, similar to the case in free STB and STB–TCNQ.     

Two ethyl 2-deoxy-α-d-hexo-3,7-pyranoso-3-octulosonate derivatives

In each of the two pyran­oid sugars, ethyl 2-deoxy-4,5,6,8-tetra-O-acetyl-α-d -gluco-3,7-pyran­oso-3-octulosonate, C₁₈H₂₆O₁₂, and ethyl 2-deoxy-4,5,6,8-tetra-O-benzyl-α-d -galacto-3,7-pyranoso-3-octulosonate, C₃₈H₄₂O₈, the anomeric configuration is α. The acetoxy­methyl substituent on the hexo­pyran­ose ring of the former compound and the ethoxy­carbonyl­methyl substituents in both sugars all have the gauche–trans conformation, while the benzyl­oxy­methyl substituent of the galacto­pyran­ose sugar has the trans–gauche conformation. In each structure, the anomeric hydroxy group forms an intramolecular hydrogen bond with the carbonyl O atom of the ethoxy­carbonyl­methyl substituent.     

4‐(4‐Chloro­benzyl­ideneamino)‐1,5‐dimethyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐one and 4‐(2‐chloro­benzyl­idene­amino)‐1,5‐dimethyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐one

The two title compounds, both with formula C₁₈H₁₆ClN₃O, are structurally similar Schiff bases derived from the condensation of 4‐chloro­benzaldehyde or 2‐chloro­benzaldehyde with 4‐amino­anti­pyrine in methanol solution. As expected, both compounds adopt trans configurations about the central C=N bonds. In the crystal structure of the 4‐chloro analogue, mol­ecules are linked through weak C—H⋯O hydrogen bonds, forming chains running along the a axis. In the crystal structure of the 2‐chloro analogue, mol­ecules are linked through weak C—H⋯O and C—H⋯Cl hydrogen bonds, forming layers parallel to the ab plane.     

2,6‐Di­methyl‐4‐(phenyl­diazenyl)­phenol

The crystal structure of the title compound, C₁₄H₁₄N₂O, determined at 293 K, shows that the mol­ecule is approximately planar in the solid state and that the aromatic rings have a trans configuration with respect to the azo double bond, as found for other diazene derivatives. The packing can be described as a polymeric arrangement of mol­ecules linked through O—H⋯N and C—H⋯O hydrogen bonds and close contacts. These intermolecular interactions result in the formation of infinite chains parallel to the b axis.     

Three ginkgolide hydrates from Ginkgo biloba L.: ginkgolide A monohydrate,ginkgolide C sesquihydrate and ginkgolide J dihydrate,all determined at 120 K

A low‐temperature structure of ginkgolide A monohydrate, (1R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)‐3‐(1,1‐dimethylethyl)‐hexa­hydro‐4,7b‐di­hydroxy‐8‐methyl‐9H‐1,7a‐epoxymethano‐1H,6aH‐cyclo­penta­[c]­furo­[2,3‐b]­furo­[3′,2′:3,4]­cyclopenta­[1,2‐d]­furan‐5,9,12(4H)‐trione monohydrate, C₂₀H₂₄O₉·H₂O, obtained from Mo Kα data, is a factor of three more precise than the previous room‐temperature determination. A refinement of the ginkgolide A monohydrate structure with Cu Kα data has allowed the assignment of the absolute configuration of the series of compounds. Ginkgolide C sesquihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11S,11aR)‐3‐(1,1‐di­methyl­ethyl)‐hexa­hydro‐2,4,7b,11‐tetrahydroxy‐8‐methyl‐9H‐1,7a‐epoxy­methano‐1H,6aH‐cyclopenta­[c]­furo­[2,3‐b]­furo­[3′,2′:3,4]­cyclo­penta­[1,2‐d]­furan‐5,9,12(4H)‐trione sesquihydrate, C₂₀H₂₄O₁₁·1.5H₂O, has two independent diterpene mol­ecules, both of which exhibit intramolecular hydrogen bonding between OH groups. Ginkgolide J dihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)‐3‐(1,1‐di­methyl­ethyl)‐hexa­hydro‐2,4,7b‐tri­hydroxy‐8‐methyl‐9H‐1,7a‐epoxy­methano‐1H,6aH‐cyclo­penta­[c]­furo­[2,3‐b]furo[3′,2′:3,4]­cyclo­penta­[1,2‐d]­furan‐5,9,12(4H)‐trione dihydrate, C₂₀H₂₄O₁₀·2H₂O, has the same basic skeleton as the other ginkgolides, with its three OH groups having the same configurations as those in ginkgolide C. The conformations of the six five‐membered rings are quite similar across ­ginkgolides A–C and J, except for the A and F rings of ginkgolide A.     

The C form of n‐hexa­decanoic acid

In the crystal structure of the title compound, C₁₆H₃₂O₂, the mol­ecules are arranged into dimers through O—H⋯O hydrogen bonds. These dimers are packed in bilayers with terminal methyl groups at both external faces, and these layers are parallel to the crystallographic (100) plane. All C—C bonds of the alkyl chain show an anti­periplanar (trans) conformation, with slight deviations from the ideal value in the C—C bonds close to the inter­molecular hydrogen bonds. The similarity between the carb­oxyl C—O bond distances is consistent with the existence of cis–trans tautomerism.     

Chalcone epoxide inter­mediates in the syntheses of lignin‐related phenyl­coumarans

Compounds (2R*,3S*)‐1‐(3,4‐dimethoxy­phen­yl)‐3‐{3‐meth­oxy‐2‐[(2R*)‐tetra­hydro­pyran‐2‐yl­oxy]phen­yl}‐2,3‐ep­oxy‐1‐propanone, C₂₃H₂₆O₇, (I), and trans‐1‐(3,4‐dimethoxy­phen­yl)‐3‐[3‐meth­oxy‐2‐(methoxy­methoxy)­phen­yl]‐2,3‐ep­oxy‐1‐propanone, C₂₀H₂₂O₇, (II), were obtained on epoxidation of chalcones. The stereochemistries of (I) and (II) were elucidated. In both compounds, the substituents on the oxirane ring are trans‐oriented. Compound (I) was obtained together with a diastereometric form that differs from (I) with respect to the configuration of the asymmetric C atom in the tetra­hydro­pyran group. The geometries of the substituted oxirane rings of (I) and (II) are very similar. The hydrogen‐bonding patterns, mediated via weak C—H⋯O inter­actions, differ considerably. The crystal structures of (I) and (II) are compared with those of related chalcone epoxides. The conversion of (I) and (II) into lignin‐related phenyl­coumarans is discussed.     

10‐Ethyl‐3‐(4‐methoxy­phenyl)‐1,2,4‐triazolo­[4′,3′:2,3]‐1,2,4‐triazino[5,6‐b]­indole

Oxidative cyclization of 5‐ethyl‐3‐(4‐methoxy­benzyl­idene)­hydrazino‐1,2,4‐triazino­[5,6‐b]­indole gave the linearly annel­ated title compound, C₁₉H₁₆N₆O. The skeleton is approx­imately planar, except for the ethyl group.     

Bis(μ‐diphenyl­phosphinato‐κ2O:O′)bis­[aqua­(diphenyl­phosphinato‐κO)bis­(pyridine‐κN)cobalt(II)]

In the centrosymmetric title compound, [Co₂(C₁₂H₁₀O₂P)₄(C₅H₅N)₄(H₂O)₂], each approximately octa­hedral Co atom features two trans‐coordinated pyridine mol­ecules, one water mol­ecule, a terminally coordinated monodentate diphenyl­phosphinate ligand, and two bidentate diphenyl­phosphinate ligands that bridge the two Co atoms across a centre of inversion to form a dimeric binuclear complex. The discrete mol­ecules are linked by double hydrogen bonds between the terminally coordinated diphenyl­phosphinate ligand and the water mol­ecule to form a continuous chain along the crystallographic b axis.     

Bis(acesulfamato‐κO4)diaqua­bis­(3‐methyl­pyridine‐κN)nickel(II)

In the crystal structure of the title compound [systematic name: diaqua­bis(6‐methyl‐2,2‐dioxo‐1,2,3‐oxathia­zin‐4‐olato‐κO⁴)bis­(3‐methyl­pyridine‐κN)nickel(II)], [Ni(C₄H₄NO₄S)₂(C₆H₇N)₂(H₂O)₂], the Ni^II centre resides on a centre of symmetry and has a distorted octa­hedral geometry. The basal plane is formed by two carbonyl O atoms of two monodentate trans‐oriented acesulfamate ligands and two trans aqua ligands. The axial positions in the octa­hedron are occupied by two N atoms of two trans pyridine ligands. Mol­ecules are stacked in columns running along the a axis. There are π–π stacking inter­actions between the mol­ecules in each column, with a distance of 3.623 (2) Å between the centroids of the pyridine rings. There are also O—H⋯O inter­actions between the columns.