4,4′-Di-tert-butyl-2,2′-dipyridinium dichloride

In the title compound, C18H26N2 2+·2Cl−, the complete dication is generated by crystallographic inversion symmetry; both N atoms are protonated and engaged in strong and highly directional N—H⋯Cl hydrogen bonds. Additional weak C—H⋯Cl contacts promote the formation of a tape along ca. [110]. The crystal structure can be described by the parallel packing of these tapes. The crystal studied was a non-merohedral twin with twin law [−1 0 0, 0 −1 0, −0.887 0.179 1] and the final BASF parameter refining to 0.026 (2)

Tris(4,4′-di-tert-butyl-2,2′-bipyridine-κ2 N,N′)molybdenum(II) μ6-oxido-dodeca-μ2-oxido-hexa­oxidohexa­molybdate(VI) acetonitrile tetra­solvate

The asymmetric unit of the title compound, [Mo(C18H24N2)3][Mo6O19]·4CH3CN, comprises an [Mo(di-t-Bu-bipy)3]2+ cation (di-t-Bu-bipy is 4,4′-di-tert-butyl-2,2′-bipyridine), two halves of Lindqvist-type [Mo6O19]2− anions (with each anion completed by the application of a center of inversion) and four acetonitrile solvent mol­ecules. The geometry around the metal atom of the cation resembles a distorted octa­hedron, with each of the three di-t-Bu-bipy ligands being almost planar [deviation from planarity < 6.3 (2)°]. Supra­molecular inter­actions, namely Mo=O⋯π, C N⋯π, C—H⋯O and C—H⋯N, along with electrostatic forces, mediate the crystal packing. Two of the tert-butyl groups are affected by rotational disorder which was modeled over two distinct positions with major site occupancies of 0.707 (9) and 0.769 (8)

4,4′-Di-tert-butyl-2,2′-bipyridine

In the title compound, C18H24N2, the mol­ecular unit adopts a trans conformation around the central C—C bond [N—C—C—N torsion angle of 179.2 (3)°], with the two aromatic rings almost coplanar [dihedral angle of only 0.70 (4)°]. The crystal packing is driven by co-operative contacts involving weak C—H⋯N and C—H⋯π inter­actions, and also the need to fill effectively the available space

1-Hydr­oxy-1,1,3,3,3-penta­phenyl­disiloxane, [Si2O(OH)(Ph)5], at 150 K

In the crystal structure of the title compound, C30H26O2Si2, one Si(Ph)3 residue is bound to another Si(OH)(Ph)2 residue via a nonlinear Si—O—Si bridge. The asymmetric unit is composed of four [Si2O(OH)(Ph)5] molecules. Each pair of adjacent molecules inter­acts via strong and highly directional O—H⋯O hydrogen bonds connecting neighbouring Si—OH units, and via inter-unit O—H⋯π contacts connecting the second hydroxyl groups with adjacent phenyl groups

2-(1H-Pyrazol-3-yl)pyridinium chloride monohydrate

The title organic salt, C8H8N3 +·Cl−·H2O, exhibits a rich hydrogen-bonding network involving all constituent species. The water mol­ecules are engaged in strong O—H⋯Cl inter­actions with the chloride anions, two neighboring protonated 2-(1H-pyrazol-3-yl)pyridinium species inter­act via N—H⋯N bonds with two pyrazole rings. Further, a short and highly directional C—H⋯O inter­action is observed connecting the pyridinium ring to the water mol­ecule of crystallization. Weak C—H⋯Cl and N—H⋯Cl inter­actions contribute to the stabilization of the crystal structure

Crystal structure of an organic-inorganic supramolecular salt based on a 4,4 '-methylenebis(3,5-dimethyl-1H-pyrazol-2-ium) cation and a beta-octamolybdate anion

The asymmetric unit of the title compound, bis[4,4'-methylenebis(3,5-dimethyl-1H-pyrazol-2-ium)] beta-octamolybdate, (C11H18N4)(2)[Mo8O26] or (H(4)mbdpz)(2)[Mo8O26], is composed of an H(4)mbdpz(2+) cation and half of the beta-octamolybdate anion which is completed by inversion symmetry. The organic molecular units are engaged in a series of N-H center dot center dot center dot O hydrogen bonds with neighbouring anions, with N center dot center dot center dot O distances and N-H center dot center dot center dot O angles in the ranges 2.730 (2)-2.941 (2) angstrom and 122-166 degrees, respectively. These interactions lead to the formation of a supramolecular two-dimensional network parallel to the (010) plane

Catalytic application of an octamolybdate salt (H(3)biim)(4)[beta-Mo8O26] in olefin epoxidation (H(2)biim=2,2'-biimidazole)

The octamolybdate salt (H3biim)4[b-Mo8O26] (1) has been prepared in good yield by hydrolysis of the complex [MoO2Cl2(H2biim)] (H2biim = 2,20-biimidazole). Compound 1 showed a good performance as a (pre)catalyst for the epoxidation of olefins using either tert-butylhydroperoxide (TBHP) or hydrogen peroxide as oxidant. With the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide) as co-solvent and TBHP as oxidant, the catalyst system could be reused several times without loss of activity for the epoxidation of the bio-olefin methyl oleate (Ole). Compound 1 is the first polyoxomolybdate used for the Ole/TBHP reaction in IL medium

1-Hydroxy-1,1,3,3,3-pentaphenyldisiloxane, [Si2O(OH)(Ph)5], at 100 K

In the crystal structure of the title compound, C30H26O2Si2, one Si(Ph)3 residue is bound to another Si(OH)(Ph)2 residue via a non-linear Si&#8212;O&#8212;Si bridge. The asymmetric unit is composed of two such molecules which interact, on the one hand, via a strong and highly directional O&#8212;H...O hydrogen bond involving the two neighbouring Si&#8212;OH units and, on the other, via an O&#8212;H...&#960; contact connecting the second hydroxyl group with an adjacent phenyl group

Oxidation of sulfides in aqueous media catalyzed by pyrazole-oxidoperoxido-molybdenum(VI) complexes

The complex [MoO(O2)2(pyrazole)2] (1) is an effective catalyst for the oxidation of organic sulfides (methylphenylsulfide and diphenylsulfide). Reactions can be run in water as the only medium, at low temperature (25 °C), with low catalyst loadings (0.2 mol%) and excellent H2O2 efficiency with no significant non-productive decomposition of the oxidant. Under conditions that favor sulfone formation, the overall process, including isolation of the precipitated product (by filtration or centrifugation) and recycling of the aqueous phase containing the catalyst, can be performed in the absence of organic or ionic liquid solvents. Catalytic results with the recycled aqueous phase were the same as those obtained in the first cycle. With water as the sole solvent, 1 is a superior catalyst to the 3,5-dimethylpyrazole complexes [MoO(O2)2(dmpz)2] (2) and [Hdmpz]4[Mo8O25.8(O2)0.2(dmpz)2]·4H2O (3). Crystal structures for 1 and 3 are presented.publishe

Microwave-Assisted Synthesis and Crystal Structure of Oxo(diperoxo)(4,4\u27-di-tert-butyl-2,2\u27-bipyridine)-molybdenum(VI)

The oxodiperoxo complex MoO(O2)2(tbbpy) (tbbpy = 4,4\u27-di-tert-butyl-2,2\u27- bipyridine) was isolated from the reaction of MoO2Cl2(tbbpy) in water under microwaveassisted heating at 120 ºC for 4 h. The structure of the oxodiperoxo complex was determined by single crystal X-ray diffraction. The MoVI centre is seven-coordinated with a geometry which strongly resembles a highly distorted bipyramid. Individual MoO(O2)2(tbbpy) complexes are interdigitated along the [010] direction to form a column. The crystal structure is formed by the close packing of the columnar-stacked complexes. Interactions between neighbouring columns are essentially of van der Waals type mediated by the need to effectively fill the available space