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.     

cis‐Dioxocyclam

Molecules of 1,4,8,11‐tetra­aza­cyclo­tetra­decane‐5,7‐dione, or cis‐dioxocyclam, C₁₀H₂₀N₄O₂, lie across mirror planes in space group Cmca; the crystal structure reveals interleaved columns of cis‐dioxocyclam mol­ecules along the 2₁ screw axis parallel to the crystallographic b axis. The columns are interconnected in a chain‐like arrangement by an amido hydrogen‐bonding network (N?O = 2.816 Å) and an amino hydrogen‐bonding network (N?N = 3.193 Å). The intracolumn spacing is 9.02 Å.     

cis‐Verbenol

cis‐Verbenol (alternative name: 4,6,6‐tri­methyl­bi­cyclo­[3.1.1]­hept‐3‐en‐2‐ol), C₁₀H₁₆O, forms an orthorhombic P2₁2₁2₁ crystal that contains three mol­ecules per asymmetric unit. These three mol­ecules form hydrogen‐bonded helices parallel to the shortest axis of the lattice. The O?O distances associated with the hydrogen bonds are 2.760 (3), 2.760 (3) and 2.766 (3) Å.     

NiII and ZnII complexes of the hexadentate macrocyclic ligand cis‐6,13‐di­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐di­amine

The title pendent‐arm macrocyclic hexa­amine ligand binds stereospecifically in a hexadentate manner, and we report here its isomorphous Ni^II and Zn^II complexes (both as perchlorate salts), namely (cis‐6,13‐di­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐di­amine‐κ⁶N)­nickel(II) di­per­chlorate, [Ni(C₁₂H₃₀N₆)]­­(ClO₄)₂, and (cis‐6,13‐di­methyl‐1,4,8,11‐tetraaza‐cyclo­tetra­decane‐6,13‐di­amine‐κ⁶N)­zinc(II) di­per­chlorate, [Zn(C₁₂H₃₀N₆)]­(ClO₄)₂. Distortion of the N—M—N valence angles from their ideal octahedral values becomes more pronounced with increasing metal‐ion size and the present results are compared with other structures of this ligand.     

Hydro­gen‐bonding patterns in cis‐4‐ammonio­cyclo­hexane­carboxyl­ate hemihydrate

In the title compound, C₇H₁₃NO₂·0.5H₂O, cis‐4‐amino­cyclo­hexane­carboxylic acid exists as a zwitterion and co‐crystallizes with water mol­ecules in a 2:1 amino acid–water ratio. The cyclo­hexane ring adopts a chair conformation, with the carboxyl­ate and ammonium groups in axial and equatorial positions, respectively. The basic motif in the crystal structure is a sandwich structure, formed by two amino acid units linked by head‐to‐tail hydrogen bonds. Hydro­gen bonds of the type N⁺—H⋯O—C—O⁻ link these motifs, forming helicoidally extended chains running along the c axis. The water molecule lies on a twofold axis and interacts with the chains by means of O—H⋯O hydrogen bonds.     

Platinum complexes of oxopurines: cis‐bis(theophyllinato‐N7)bis(triphenylphosphine)platinum(II) and cis‐chloro(theobrominato‐N1)bis(triphenylphosphine)platinum(II) ethanol hemisolvate

The syntheses and structures of two mixed‐ligand complexes of platinum(II) with deprotonated oxopurine bases and tri­phenyl­phosphine are reported, namely the theophyllinate complex cis‐bis(1,2,3,6‐tetra­hydro‐1,3‐di­methyl­purine‐2,6‐dionato‐κN⁷)­bis(tri­phenyl­phosphine‐κP)­platinum(II), [Pt(C₇H₇N₄O₂)₂(C₁₈H₁₅P)₂], (I), and the theobrominate complex cis‐chloro(1,2,3,6‐tetrahydro‐3,7‐dimethylpurine‐2,6‐dionato‐κN¹)­bis(tri­phenyl­phosphine‐κP)­platinum(II) ethanol hemisolvate, [PtCl(C₇H₇N₄O₂)(C₁₈H₁₅P)₂]·0.5C₂H₅OH, (II). In (I), the coordination geometry of Pt is square planar, formed by the two coordinating N atoms of the theophyl­linate anions in a cis arrangement and two P atoms from the tri­phenyl­phosphine groups. In (II), there are two crystallographically independent mol­ecules. They both exhibit a square‐planar coordination geometry around Pt involving one Cl atom, the coordinating N atom of the theobrominate anion and two P atoms from the tri­phenyl­phosphine groups. The two tri­phenyl­phosphine groups are arranged in a cis configuration in both structures. The heterocyclic rings are rotated with respect to the coordination plane of the metal by 82.99 (8) and 88.09 (8)° in complex (I), and by 85.91 (16) and 88.14 (18)° in complex (II). Both structures are stabilized by intramolecular stacking interactions involving the purine rings and the phenyl rings of adjacent tri­phenyl­phosphine moieties.     

cis,cis,cis‐1,2,4,5‐Cyclo­hexane­tetra­carboxyl­ic acid and its dianhydride

cis,cis,cis‐1,2,4,5‐Cyclo­hexane­tetra­carboxyl­ic acid, C₁₀H₁₂O₈, (I), contains a mirror plane and the cyclo­hexane ring exhibits a chair conformation. Two crystallographically independent hydrogen bonds form (14), (16) and (16) ring motifs, and propagation of these two hydrogen bonds along the c and b axes generates (16) and (7) chains. cis,cis,cis‐1,2:4,5‐Cyclo­hexane­tetra­carboxyl­ic dianhydride, C₁₀H₈O₆, (II), was prepared by the reaction of (I) with acetic anhydride. The cyclo­hexane ring of (II) exhibits a boat conformation and the dihedral angle between the two an­hydro rings is 117.5 (1)°.     

Dicarbonyldi‐μ‐chloro‐cis,cis‐η4‐1,5‐cyclo­octa­dienedirhodium(I)

The title compound, dicarbonyl‐1κ²C‐di‐μ‐chloro‐1:2κ⁴Cl‐[cis,cis‐2(η⁴)‐1,5‐cyclo­octa­diene]­di­rhodium(I), [Rh₂Cl₂(C₈H₁₂)(CO)₂], consists of a di­chloro‐bridged dimer of rhodium, with a non‐bonded Rh?Rh distance of 3.284 (2) Å. One Rh atom is coordinated to two carbonyl ligands, while the other Rh atom is coordinated to the cyclo­octa­diene moiety.     

cis‐Di­chloro(5,8‐dioxa‐2,11‐dithia[12]‐o‐cyclo­phane)­palladium(II)

The preparation and crystal structure of the title compound, cis‐di­chloro­[6,9‐dioxa‐3,12‐di­thia­bi­cyclo­[12.4.0]­octadeca‐14,‐16,­18(1)‐tri­ene‐S,S′]­palladium(II), [PdCl₂(C₁₄H₂₀O₂S₂)], are described. The Pd atom has a square‐planar environment, coordinated to two S atoms of the di­thia­dioxa macrocycle and to two Cl^? ions. The non‐coordinating O atoms are oriented away from the metal coordination plane. Upon complexation, a bicyclic chelate structure, which consists of a seven‐ and an eleven‐membered ring, is formed.     

cis‐Bis[(3‐amino­prop­yl)dimethyl­phosphine‐κ2N,P]palladium(II) dichloride methanol solvate

In the title compound, cis‐[Pd(C₅H₁₄NP)₂]Cl₂·CH₄O, the coordination geometry around the Pd^II center is distorted square planar, with a cis‐P₂N₂ configuration of the two chelating (3‐amino­prop­yl)dimethyl­phosphine (pdmp) ligands. The six‐membered pdmp chelate rings adopt chair conformations, and pairing of the chairs designates the complex cation as a (C_s)‐chair₂ conformer. The distances between the Pd^II center and the Cl⁻ anions are greater than 4.5 Å, indicating no obvious inter­action.     

cis‐Tetracarbonylbis(tricyclohexyl­phosphine)molybdenum(0) and pentacarbonyl(tricyclohexylphos­phine)molybdenum(0)

In the present redetermination of the complex cis‐tetra­carbonyl­bis­(tri­cyclo­hexyl­phosphine)molybdenum(0), (I), [Mo(C₁₈H₃₃P)₂(CO)₄] or cis‐{η¹‐[P(C₆H₁₁)₃]₂}Mo(CO)₄, the Mo atom has a distorted octahedral geometry with a large P—Mo—P angle of 104.8 (1)°. A strong trans influence on the carbonyls in (I) is seen in a shortening of the Mo—C and a lengthening of the C—O distances opposite the phosphines compared with those that are cis. This influence is greatly diminished in the complex penta­carbonyl­(tri­cyclo­hexyl­phosphine)­molyb­denum(0), (II), [Mo(C₁₈H₃₃P)(CO)₅] or {η¹‐[P(C₆H₁₁)₃]}­Mo(CO)₅, the core of which has a slightly distorted C_4v geometry.     

trans‐Di­chloro‐cis‐bis(3,6‐di­methyl­carbazolyl)‐cis‐bis­(tetra­hydro­furan)­zirconium(IV) benzene sesquisolvate

In the title compound, [ZrCl₂(C₁₄H₁₂N)₂(C₄H₈O)₂]·1.5C₆H₆, the Zr atom is pseudo‐octahedral, with two Cl atoms in trans positions and two tetra­hydro­furan mol­ecules in cis positions. The two 3,6‐di­methyl­carbazolyl ligands are in cis positions and are canted with respect to one another. The two Zr—N distances are 2.1148 (18) and 2.1236 (18) Å, and the N—Zr—N angle is 95.08 (7)°. The title compound crystallizes as the benzene solvate, with one of the benzene mol­ecules positioned on an inversion center.     

cyclo(‐Cha–Oxz–d‐Val–Thz–Ile–Oxz–d‐Val–Thz‐) N,N‐di­methyl­acetamide dihydrate: a square form of cyclo­hexyl­alanine‐incorporated ascidiacycl­amide having the strongest cytotoxicity

The title compound, 1‐cyclo­hexyl­methyl‐1‐de(1‐methyl­propyl)­asci­dia­cycl­amide N,N‐di­methyl­acet­amide di­hy­drate, C₃₉H₅₆N₈O₆S₂·C₄H₉NO·2H₂O, a cyclo­hexyl­alanine‐incorporated ascidiacycl­amide analogue ([Cha]ASC), shows a square form similar to natural ASC. On the other hand, CD (circular dichroism) spectra showed [Cha]ASC to have a folded structure in solution, making it the second known analogue to show a discrepancy between its crystal and solution structures. Moreover, the cytotoxicity of [Cha]ASC (ED₅₀ = 5.6 µg ml⁻¹) was approximately two times stronger than that of natural ASC or a related phenyl­alanine‐incorporated analogue, viz. cyclo(‐Phe–Oxz–d ‐Val–Thz–Ile–Oxz–d ‐Val–Thz‐) ([Phe]ASC), and was confirmed to be associated with the square form. However, [Phe]ASC was previously shown to be folded in the crystal structure, which suggests that the difference between the aromatic and aliphatic rings affects the molecular folding of the ASC mol­ecule.     

cis‐Bis(3,6‐di­hydro‐2H‐1,2‐oxazine‐N)­di­iodo­platinum(II) and cis‐bis(3,4,5,6‐tetra­hydro‐2H‐1,2‐oxazine‐N)­di­iodo­platinum(II)

The title complexes, [Pt(C₄H₇NO)₂I₂], (I), and [Pt(C₄H₉NO)₂I₂], (II), possess similar square‐planar coordination geometries with modest distortions from ideality. For (I), the cis‐L—Pt—L angles are in the range 87.0 (4)–94.2 (3)°, while the trans angles are 174.4 (3) and 176.4 (3)°. For (II), cis‐L—Pt—L are 86.1 (8)–94.2 (6)° and trans‐L—Pt—L are 174.4 (6) and 177.4 (5)°. One 3,6‐di­hydro‐2H‐1,2‐oxazine ligand in (I) is rotated so that the N—O bond is out of the square plane by approximately 70°, while the N—C bond is only ca 20° out of the plane. The other oxazine ligand is rotated so that the N—C bond is about 80° out of the plane, while the N—O bond is out of the plane by approximately 24°. In (II), the 3,4,5,6‐tetra­hydro‐2H‐1,2‐oxazine ligands are also positioned with one having the N—O bond further out of the plane and the other having the N—C bond positioned in that fashion. Both ligands, however, are rotated approximately 90° compared with their positions in (I). In both complexes, this results in an unsymmetrical distortion of the I—Pt—N bond angles in which one is expanded and the other contracted. These features are compared to those of reported cis‐di­amine­di­iodo­platinum(II) complexes.     

cis‐ and trans‐2‐(4‐tert‐Butylcyclohexyloxy)‐1,3,5‐trinitrobenzene

The structures of cis‐ and trans‐2‐(4‐tert‐butyl­cyclo­hexyl­oxy)‐1,3,5‐tri­nitro­benzene, C₁₆H₂₁N₃O₇, (I) and (II), respectively, were determined at low temperature in order to obtain accurate structural parameters for comparison purposes. The C_alkyl—O_ether bond distances are 1.497 (2) and 1.491 (2) Å for (I) and (II), respectively.     

Magnesium iodide–4,4′‐bipyridine–water (1/3/4) and strontium iodide–4,4′‐bipyridine–propan‐1‐ol (1/2.5/2)

Both of the title compounds, catena‐poly­[[[tetra­aqua­magnesium(I)]‐μ‐4,4′‐bi­pyridine‐κ²N:N′] diiodide bis(4,4′‐bi­pyridine) solvate], {[Mg(C₁₀H₈N₂)(H₂O)₄]I₂·2C₁₀H₈N₂}_n, (I), and catena‐poly­[[[μ‐4,4′‐bi­pyridine‐bis­[di­iodo­bis­(propan‐1‐ol)­strontium(I)]]‐di‐μ‐4,4′‐bi­pyridine‐κ⁴N:N′] bis(4,4′‐bi­pyri­dine) solvate], {[Sr₂I₄(C₁₀H₈N₂)₃(C₃H₈O)₄]·2C₁₀H₈N₂}_n, (II), are one‐dimensional polymers which are single‐ and double‐stranded, respectively, the metal atoms being linked by the 4,4′‐bi­pyridine moieties. The Mg complex, (I), is [cis‐{(H₂O)₄Mg(N‐4,4′‐bi­pyridine‐N′)_(2/2)}]_(∞|∞)I₂·4,4′‐bi­pyridine and Mg has a six‐coordinate quasi‐octahedral coordination environment. The Sr complex, (II), is isomorphous with its previously defined Ba counterpart [Kepert, Waters & White (1996). Aust. J. Chem. 49 , 117–135], being [(propan‐1‐ol)₂I₂Sr(N‐4,4′‐bi­pyridine‐N′)_(3/2)]_(∞|∞)·4,4′‐bi­pyridine, with the I atoms trans‐axial in a seven‐coordinate pentagonal–bipyramidal Sr environment.     

Hydrogen bonding in polyamino‐polyalcohols: a monohydrated cocrystal of 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol iodide and 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol

In the title monohydrated cocrystal, namely 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol iodide–1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol–water (1/1/1), C₆H₁₆N₃O₃⁺·I⁻·C₆H₁₅N₃O₃·H₂O, the neutral 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol (taci) molecule and the monoprotonated 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol cation (Htaci⁺) both adopt a chair conformation, with the three O atoms in axial and the three N atoms in equatorial positions. The cation, but not the neutral taci unit, exhibits intramolecular O—H...O hydrogen bonding. The entire structure is stabilized by a complex three‐dimensional network of intermolecular hydrogen bonds. The neutral taci entities and the Htaci⁺ cations are each aligned into chains along [001]. In these chains, two O—H...N interactions generate a ten‐membered ring as the predominant structural motif. The rings consist of vicinal 2‐amino‐1‐hydroxyethylene units of neighbouring molecules, which are paired via centres of inversion. The chains are interconnected into undulating layers parallel to the ac plane, and the layers are further held together by O—H...N hydrogen bonds and additional interactions with the iodide counter‐anions and solvent water molecules.     

3,6‐Di­chloro‐4‐[2‐(4‐thia­morpholino)­ethanesulfanyl]­pyridazine and 3,6‐bis­(pyrazol‐1‐yl)‐4‐[2‐(4‐thia­mor­pho­lino)­ethanesulfanyl]­pyridazine

The trans–trans conformations adopted by the derivatized bis­(bidentate) chelating N₄‐donor ligand 3,6‐bis­(pyrazol‐1‐yl)‐4‐[2‐(4‐thia­morpholino)­ethanesulfanyl]­pyridazine, C₁₆H₁₉N₇S₂, and an intermediate in its formation, 3,6‐di­chloro‐4‐[2‐(4‐thia­morpholino)­ethanesulfanyl]­pyridazine, C₁₀H₁₃Cl₂N₃S₂, con­trast with the cis–cis conformation found previously for 3,6‐bis­(thio­phen‐2‐yl)­pyridazine [Ackers, Blake, Hill & Hubberstey (2002). Acta Cryst. C 58 , o640–o641], which places all four heteroatoms on the same side of the mol­ecule.     

Hydro­gen bonding in calcium–tri­fluoro­methane­sulfonate–1,3‐di‐4‐pyridyl­urea–methanol (1/2/2/4)

The structure of the supramolecular complex calcium–tri­fluoro­methane­sulfonate–1,3‐di‐4‐pyridyl­urea–methanol (1/2/2/4), Ca²⁺·2CF₃SO₃⁻·2C₁₁H₁₀N₄O·4CH₄O, is presented. The Ca²⁺ ion lies on an inversion centre and is octahedrally coordinated by four methanol mol­ecules and two tri­fluoro­methane­sulfonate counter‐ions. The molecular packing is dominated by hydrogen‐bonded sheets in the (110) plane which contain R(32) rings; in these rings, significant π–π interactions are observed between inversion‐related 1,3‐di‐4‐pyridyl­urea mol­ecules.     

A cis‐stilbene derivative

The title compound, 4′‐methoxy‐α,2,3′,4‐tetra­nitro­stilbene, C₁₅H₁₀N₄O₉, crystallizes in the centrosymmetric space group P2₁/c with one mol­ecule in the asymmetric unit. The phenyl rings are inclined to one another and form a dihedral angle of 57.4 (1)°. The size of this angle is a result of intermolecular C—H⃛O interactions involving the phenyl H atoms. The torsion angle between the phenyl rings, −7.5 (3)°, indicates a cis geometry between them. The methoxy group is almost coplanar with the phenyl ring, and the nitro groups are twisted with respect to the phenyl rings because of the short H⃛O contacts. The crystal packing is stabilized by C—H⃛O hydrogen bonds, and the intermolecular hydrogen bonds form a C(12) graph‐set chain running along the [010] direction.