Bis(4,4′‐bipyridinium) hexa­cyano­platinate(IV) bis­(4,4′‐bipyridine)

In the title compound, (C₁₀H₉N₂)₂[Pt(CN)₆]·2C₁₀H₈N₂ or [(Hbpy)⁺]₂[Pt(CN)₆]²⁻·2bpy, where bpy is 4,4′‐bipyridine, the Hbpy⁺ cations and bpy mol­ecules form a hydrogen‐bonded two‐dimensional cationic approximately square grid parallel to the (110) plane. The [Pt(CN)₆]²⁻ dianions reside in the cavities within this grid, with the nitrile N atoms forming weak hydrogen bonds with the CH groups in the cationic lattice.     

3‐Germyl‐3,3‐di­methyl­propionic acid derivatives

The crystal structures of 3,3‐di­methyl‐3‐(tri­chloro­germyl)­propionic acid, [Ge(C₅H₉O₂)Cl₃], 3,3‐di­methyl‐3‐(tri­phenyl­germyl)­propionic acid, [Ge(C₆H₅)₃(C₅H₉O₂)], and 3,3‐di­methyl‐3‐(tri‐p‐toly­lgermyl)­propionic acid, [Ge(C₇H₇)₃(C₅H₉O₂)], have slightly distorted tetrahedral geometries about the Ge atoms. All the structures form dimers via strong O—H·O hydrogen bonds, resulting in eight‐membered rings that can be best described in terms of graph‐set notation (8).     

A novel copper(II) coordination polymer with 2,2′‐bipyridyl‐3,3′‐di­carboxylic acid

A novel copper(II) coordination polymer, poly­[[[aqua­copper(II)]‐μ₃‐2,2′‐bipyridyl‐3,3′‐di­carboxyl­ato‐κ⁴N,N′:O:O′] dihydrate], {[Cu(C₁₂H₆N₂O₄)(H₂O)]·2H₂O}_n, was obtained by the reaction of CuCl₂·2H₂O and 2,2′‐bipyridyl‐3,3′‐di­carboxylic acid (H₂L) in water. In the mol­ecule, each Cu^II atom is five‐coordinated and lies at the centre of a square‐pyramidal basal plane, bridged by three L ligands to form a two‐dimensional (4,4)‐network. Each L moiety acts as a bridging tetradentate ligand, coordinating to three Cu^II atoms through its two aromatic N atoms and two O atoms of the two carboxyl groups. The two‐dimensional square‐grid sheets superimpose in an off‐set fashion through the inorganic water layer.     

1,1′‐Di­acetyl‐3‐hydroxy‐2,2′,3,3′‐tetra­hydro‐3,3′‐bi(1H‐indole)‐2,2′‐dione

In the title compound, C₂₀H₁₆N₂O₅, both of the 1‐acetyl­isatin (1‐acetyl‐1H‐indole‐2,3‐dione) moieties are planar and form a dihedral angle of 74.1 (1)°. Weak intermolecular hydrogen bonds and C—H?π interactions stabilize the packing in the crystal.     

3,3′,5,5′‐Tetramethyl‐4,4′‐bipyrazole–pentafluorophenol (2/3)

In the title compound, 2C₁₀H₁₄N₄·3C₆HF₅O, one of the pentafluorophenol molecules resides on a mirror plane bisecting the O...F axis. The components aggregate by N—H...N, N—H...O and O—H...N hydrogen bonds involving equal disordering of the H atoms into molecular ensembles based on a 2:1 pyrazole–phenol cyclic pattern [O...N = 2.7768 (16) Å and N...N = 2.859 (2) Å], crosslinked into one‐dimensional columns via hydrogen bonding between the outer pyrazole groups and additional pentafluorophenol molecules. The latter yields a 1:1 pyrazole–phenol catemer with alternating strong O—H...N [2.5975 (16) Å] and weaker N—H...O [2.8719 (17) Å] hydrogen bonds. This is the first reported molecular adduct of a pentafluorinated phenol and a nitrogen base, and suggests the utility of highly acidic phenols and pyrazoles for developing hydrogen‐bonded cocrystals.     

3,3′‐Dinitro‐2,2′‐dithiodipyridine

In the title compound, C₁₀H₆N₄O₄S₂, (I), the molecule has a centre of inversion. The structure is a positional isomer of 5,5′‐dinitro‐2,2′‐dithiodipyridine [Brito, Mundaca, Cárdenas, López‐Rodríguez & Vargas (2007). Acta Cryst. E 63 , o3351–o3352], (II). The 3‐nitropyridine fragment of (I) shows excellent agreement with the bonding geometries of (II). The most obvious differences between them are in the S—S bond length [2.1167 (12) Å in (I) and 2.0719 (11) Å in (II)], and in the C—C_ipso—N_ring [119.8 (2)° in (I) and 123.9 (3)° in (II)] and S—C—C [122.62 (18)° in (I) and 116.0 (2)° in (II)] angles. The crystal structure of (I) has an intramolecular C—H...O interaction, with an H...O distance of 2.40 (3) Å, whereas this kind of interaction is not evident in (II). The molecules of (I) are linked into centrosymmetric R⁴₄(30) motifs by a C—H...O interaction. There are no aromatic π–π stacking and no C—H...π(arene) interactions. Compound (I) can be used as a nucleophilic tecton in self‐assembly reactions with metal centres of varying lability.     

A novel cadmium(II) coordination polymer with biphenyl‐3,3′,4,4′‐tetra­carboxylic acid and 4,4′‐bipyridine

A novel cadmium(II) coordination polymer, poly[[[bis­(4,4′‐bipyridine)cadmium(II)]‐μ₃‐4,4′‐dicarboxy­biphenyl‐3,3′‐di­carboxyl­ato] 0.35‐hydrate], {[Cd(C₁₆H₈O₈)(C₁₀H₈N₂)₂]·0.35H₂O}_n, was obtained by reaction of Cd(CH₃COO)₂·3H₂O, 4,4′‐bipyridine (4,4′‐bpy) and biphenyl‐3,3′,4,4′‐tetra­car­boxylic acid (H₄L) under hydro­thermal conditions. Each Cd^II atom lies at the centre of a distorted octa­hedron, coordinated by four O atoms from three H₂L²⁻ ligands and N atoms from two monodentate 4,4′‐bpy ligands. Each H₂L²⁻ ligand coordinates to three Cd^II atoms through two carboxyl­ate groups, one acting as a bridging bidentate ligand and the other in a chelating bidentate fashion. Two Cd atoms, two H₂L²⁻ anions and four 4,4′‐bpy ligands form a ring dimer node, which links into an extended broad zonal one‐dimensional chain along the c axis.     

1,1′‐Dimethoxy‐3,3′‐dimethyl‐3,3′‐(hexane‐1,6‐diyl)bis(triazen‐2‐ium‐2‐olate): a nitric oxide donor

The title compound, C₁₀H₂₄N₆O₄, is the most stable type of nitric oxide (NO) donor among the broad category of discrete N‐diazeniumdiolates (NO adducts of nucleophilic small molecule amines). Sitting astride a crystallographic inversion center, the molecule contains a symmetric dimethylhexane‐1,6‐diamine structure bearing two planar O²‐methylated N‐diazeniumdiolate functional groups [N(O)=NOMe]. These two groups are parallel to each other and have the potential to release four molecules of NO. The methylated diazeniumdiolate substituent removes the negative charge from the typical N(O)=NO⁻ group, thereby increasing the stability of the diazeniumdiolate structure. The crystal was nonmerohedrally twinned by a 180° rotation about the real [101] axis. This is the first N‐based bis‐diazeniumdiolate compound with a flexible aliphatic main unit to have its structure analyzed and this work demonstrates the utility of stabilizing the N‐diazeniumdiolate functional group by methylation.     

Bis[bis­(methoxy­carbimido)amine‐κ2N,N′]bis­(perchlorato‐κO)copper(II) bis­[bis­(methoxy­carbimido)amine‐κ2N,N′]bis­(methanol‐κO)copper(II) bis­(perchlorate) methanol disolvate

The title compound, [Cu(ClO₄)₂(C₄H₉N₃O₂)₂][Cu(C₄H₉N₃O₂)₂(CH₄O)₂](ClO₄)₂·2CH₃OH, comprises two independent Cu^II species lying on different inversion sites. In the Cu complexes, a distorted octa­hedral geometry arises (from basic square‐planar N₄ coordination) from the weak coordination of two perchlorate ions (as Cu—O) in one species and two methanol mol­ecules in the other (also as Cu—O). Inter­actions between the O atoms of the perchlorate anions or methanol groups and the imide or amine NH groups afford an extensive inter­molecular hydrogen‐bonding network.     

Hexaaqua­nickel(II) bis­(4′,7‐dimethoxy­isoflavone‐3′‐sulfonate) octa­hydrate

In the title compound, [Ni(H₂O)₆](C₁₇H₁₃O₇S)₂·8H₂O, the Ni^II atom is located on an inversion centre in the space group P2₁/c. The [Ni(H₂O)₆]²⁺, C₁₇H₁₃O₇S⁻ and H₂O components form many hydrogen bonds and there are π–π stacking inter­actions betweeen the isoflavone units. The hydrogen bonds, π–π stacking inter­actions and electrostatic inter­actions between the cation and anions link the components into a three‐dimensional structure.     

μ‐{N,N′‐Bis[2‐(dimethyl­amino)ethyl]oxamidato(2–)}‐1κ2O,O′:2κ4N,N′,N′′,N′′′‐bis­(4,4′‐dimethyl‐2,2′‐bipyridine‐1κ2N,N′)dinickel(II) bis­(perchlorate)

In the crystal structure of the title complex, [Ni₂(C₁₀H₂₀N₄O₂)(C₁₂H₁₂N₂)₂](ClO₄)₂ or [Ni(dmaeoxd)Ni(dmbp)₂](ClO₄)₂ {H₂dmaeoxd is N,N′‐bis­[2‐(dimethyl­amino)ethyl]oxamide and dmbp is 4,4′‐dimethyl‐2,2′‐bipyridine}, the deprotonated dmaeoxd²⁻ ligand is in a cis conformation and bridges two Ni^II atoms, one of which is located in a slightly distorted square‐planar environment, while the other is in an irregular octa­hedral environment. The cation is located on a twofold symmetry axis running through both Ni atoms. The dmaeoxd²⁻ ligands inter­act with each other via C—H⋯O hydrogen bonds and π–π inter­actions, which results in an extended chain along the c axis.     

(3R*,3′R*)‐1,1′‐Dimethyl‐3,3′‐biindoline‐2,2′‐dithione

The (3R*,3′R*) configuration of the title compound, C₁₈H₁₆N₂S₂, (I), has been unambiguously elucidated by X‐­ray analysis. Mol­ecules of (I) have C₂ symmetry to a good approximation and a strongly folded shape. The interplanar angle between the two halves of a mol­ecule is 67.11 (6)°.     

(Acetonitrile‐κN){2‐[bis­(2‐pyridylethyl)­amino]ethanol‐κ4N,N′,N′′,O}zinc(II) bis­(perchlorate) monohydrate

In the title compound, [Zn(C₂H₃N)(C₁₆H₂₁N₃O)](ClO₄)₂·H₂O, the Zn^II ion is coordinated by two pyridyl N atoms, one amine N atom, and an ethanol O atom from the N,N′,N′′,O‐tetra­dentate 2‐[bis­(2‐pyridylethyl)amino]­ethanol donor ligand. The fifth coordination site is filled by an acetonitrile N atom, and there is one solvent water mol­ecule in the asymmetric unit. The 2+ charge of the cationic portion of the complex is balanced by two perchlorate counter‐anions.     

Polymorphism and phase transition behavior of 6,6′‐bis(chloromethyl)‐1,1′,4,4′‐tetramethyl‐3,3′‐(p‐phenylenedimethylene)bis(piperazine‐2,5‐dione)

A crystallographic investigation of the title compound, C₂₂H₂₈Cl₂N₄O₄, using crystals obtained under different crystallization conditions, revealed the presence of two distinct polymorphic forms. The molecular conformation in the two polymorphs is very different: one adopts a `C' shape, whereas the other adopts an `S' shape. In the latter, the molecule lies across a crystallographic twofold axis. The `S'‐shaped polymorph undergoes a reversible orthorhombic‐to‐monoclinic phase transition on cooling, whereas the structure of the `C'‐shaped polymorph is temperature insensitive.     

1,1′‐(Ethenyl­idene)bis­(4‐chloro­benzene)

The title compound, C₁₄H₁₀Cl₂, crystallizes as colourless prisms with two symmetry‐independent mol­ecules in the unit cell. Numerous inter­molecular C—H⋯π inter­actions dominate in the crystal structure, where C—H⋯Cl and long Cl⋯Cl contacts are also observed.     

N,N′‐Bis(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide and N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide

The mol­ecules of N,N′‐bis­(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyl­dicarboxamide, [Fe(C₁₂H₁₁N₂O)₂], contain intra­molecular N—H⋯N hydrogen bonds and are linked into sheets by three independent C—H⋯O hydrogen bonds. The mol­ecules of the isomeric compound N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide lie across inversion centres, and the mol­ecules are linked into sheets by a combination of N—H⋯N hydrogen bonds and π–π stacking inter­actions between pyridyl groups.     

Poly(ethylene terephthalate) reinforced by N,N′‐diphenyl biphenyl‐3,3′,4,4′‐tetracarboxydiimide moieties

Starting with 3,3′,4,4′‐biphenyltetracarboxylic dianhydride and methyl aminobenzoate, we synthesized a novel rodlike imide‐containing monomer, N,N′‐bis[p‐(methoxy carbonyl) phenyl]‐biphenyl‐3,3′,4,4′‐tetracarboxydiimide (BMBI). The polycondensation of BMBI with dimethyl terephthalate and ethylene glycol yielded a series of copoly(ester imide)s based on the BMBI‐modified poly(ethylene terephthalate) (PET) backbone. Compared with PET, these BMBI‐modified polyesters had higher glass‐transition temperatures and higher stiffness and strength. In particular, the poly(ethylene terephthalate imide) PETI‐5, which contained 5 mol % of the imide moieties, had a glass‐transition temperature of 89.9 °C (11 °C higher than the glass‐transition temperature of PET), a tensile modulus of 869.4 MPa (20.2 % higher than that of PET), and a tensile strength of 80.8 MPa (38.8 % higher than that of PET). Therefore, a significant reinforcing effect was observed in these imide‐modified polyesters, and a new approach to higher property polyesters was suggested. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 852–863, 2002; DOI 10.1002/pola.10169     

Aqua(n‐hexyl)[3,3′‐(propane‐1,3‐diyldinitrilo)­bis­(butan‐2‐one) dioximato‐­κ4N]cobalt(III) perchlorate

The title compound, [Co(C₆H₁₃)(C₁₁H₁₉N₄O₂)(H₂O)]ClO₄, is in the general class of coenzyme B₁₂ models which contain a ClO₄ anion and a [Co(C₆H₁₃)(C₁₁H₁₉N₄O₂)(H₂O)]⁺ cation. In the cation, the Co atom has a distorted octahedral coordination, with the n‐hexyl and H₂O ligands in axial positions. The crystal data reveal some degree of flexibility in the Costa‐type system, which is similar to the coenzyme B₁₂.     

Synthesis and Characterization of 3,3′‐Bis(Dinitromethyl)‐5,5′‐Azo‐1H‐1,2,4‐Triazole

The synthesis of 3,3′‐bis(dinitromethyl)‐5,5′‐azo‐1H‐1,2,4‐triazole ( 5 ) using the readily available starting material 2‐(5‐amino‐1H‐1,2,4‐triazol‐3‐yl)acetic acid ( 1 ) is described. All compounds were characterized by means of NMR, IR, and Raman spectroscopy. The energetic compound 5 was additionally characterized by single‐crystal X‐ray diffraction and DSC measurements. The sensitivities towards impact, friction and electrical discharge were determined. In addition, detonation parameters (e.g. heat of explosion, detonation velocity) of the target compound were computed using the EXPLO5 code based on the calculated (CBS‐4M) heat of formation and X‐ray density.