A New Inclusion Compound between 2,4,5,7,9,10-hexachloro-1,3,6,8-tetrakis (4-methoxyphenylthio)pyrene Host and Cyclohexane Guest Stabilized by C–H···π and C–H···Cl Interaction

Crystal structure analysis shows the 2,4,5,7,9,10-hexachloro-1,3,6,8-tetrakis-(4-methoxyphenylthio) pyrene host and its cyclohexane guest in the Pnma crystal lattice. The crystal data and refinement parameter for the title compound are: a = 15.864(3), b = 30.455(6), c = 9.231(5) Å, V = 4459.2 (14) ų. For Z = 4 and M _w = 1045.76, the calculate density Dcal = 1.558 g/cm³. The C–H···π interaction and C–H Cl interaction stabilized the inclusion of cyclohexane molecules. The S···Cl weak interaction assembled the host molecules into a two-dimensional layer structure, and a three-dimensional structure was obtained by connecting the layers with C–H···O hydrogen bonding.Electronic Supplementary Material Supplementary material is available for this article at ^*Supplementary data: crystallographic data (atomic coordinates, anisotropic displacement parameters, selected bond distance and angles) for the structures in this paper have been deposited with the Cambridge Crystallographic Data Center with CCDC 270603 as supplementary publication.     

Low-temperature crystallization and X-ray structure determination of 2-methylpyridine at 153 K

The molecular and crystal structure of 2-methylpyridine or 2-picoline (1), melting point 206 K, was obtained from single crystal X-ray diffraction data by low-temperature crystallization of the liquid in a thin capillary on the diffractometer SMART 1000 CCD in a cold N₂ gas stream. The molecule has almost C_s symmetry with all atoms in a plane except two hydrogen atoms of the CH₃ group. Molecular geometry parameters obtained from the X-ray data and corrected for libration effect are in good agreement with those obtained from our ab initio calculations. Interesting peculiarity of the crystal packing of (1) is the C–Hπ intermolecular contact with short HX distance 2.64 Å, which can bring about the packing motif of (1) (X is the center of the aromatic ring, C is a carbon atom of the ring).     

The O–H···O, O–H···N and C–H···O hydrogen bonds in 1,4-dimethylpiperazine mono-betaine monohydrate

1,4-Dimethylpiperazine mono-betaine (1-carboxymethyl-1,4-dimethylpiperazinium inner salt, MBPZ) crystallizes as monohydrate. The crystals are orthorhombic, space group Pccn. Two MBPZ molecules and two water molecules form a cyclic oligomer, (MBPZ·H₂O)₂. The O–H···O and O–H···N hydrogen bonds are of 2.769(1) and 2.902(1) Å, respectively. The dimers interact with the neighboring molecules through the C–H···O hydrogen bonds of 3.234(1) Å. The piperazine ring assumes a chair conformation with the N(4)–CH₃ and N⁺(1)–CH₂COO⁻ groups in the equatorial position and the N⁺(1)–CH₃ group in the axial one. The FTIR spectrum is compared with that calculated by the B3LYP/6-31G(d,p) level of theory.     

A New Clathrate Featuring a Spiro-Type Ammonium Host. X-Ray Structure of the Inclusion Compound with Chloroform

A new onium salt host molecule 1 featuring a spiro-type ammonium backbone was synthesized and shown to form a crystalline inclusion compound with chloroform, 1 · chloroform (1:2), the crystal structure of which is reported. The host molecular interactions including C–H···Br, Cl···Cl and aromatic stacking contacts are typical of the packing structure.     

Synthesis,structure and spectroelectrochemical property of (2,2′-bipyridine)–metal (M = Pt,Pd) dichloride with 4,4′-bis(fluorous-ponytail) on bipyridine

The 4,4′-bis(R_fCH₂OCH₂)-2,2′-bpy ligands [R_f = n-C₃F₇ (1a), HCF₂(CF₂)₃ (1b)] were prepared and then treated with [MCl₂(CH₃CN)₂] (M = Pt or Pd) to result in the corresponding metal complexes, [MCl₂(4,4′-bis(R_fCH₂OCH₂)-2,2′-bpy)] (M = Pt 2a–b; Pd 3a–b). Both ligands and metal complexes were fully characterized by multi-nuclei NMR (¹H, ¹⁹F and ¹³C), FTIR, and mass (GC/MS or HR-FAB) methods. The X-ray structures of 2a–b and 3a–b were studied. With terminal CF₃, the structures of 2a and 3a exhibit disordered polyfluorinated regions in solid state. With terminal HCF₂, the structures of 2b and 3b show a π–π stacking of the bpy planes, five-membered C–H···O hydrogen bond and an unusual intramolecular blue-shifting C–H···F–C hydrogen bond system, whereas without terminal HCF₂, the structures of 2a and 3a show the similar π–π stacking, five-membered C–H···O hydrogen bond and typical orientation of polyfluorinated ponytails, but not the C–H···F–C hydrogen bond system. The CV and UV/Vis studies were also carried out.     

Tetrameric O–HO hydrogen-bond systems accompanied by C–HO hydrogen-bonds in the crystal of 1,4-bis(hydroxymethyl)triptycene: an X-ray study

The crystal structure of the title compound was determined (crystal data at 143 K: triclinic, space group P−1, Z=4, a=9.538(2) Å, b=11.638(2) Å, c=14.473(2) Å, α=88.647(3)°, β=89.875(3)°, γ=83.835(3)°, V=1596.9(4) ų). In the crystal there exist two kinds of tetrameric O–HO hydrogen-bond (H-bond) systems that are quite similar to each other. The oxygen atoms accept also intermolecular C–HO H-bonds. The two types of the H-bonds connect the molecules to an infinite two-dimensional supramolecular unit, the stacking of which is aided by an intermolecular C–Hπ H-bond. A phase transition with ΔH_t=4.4±0.1 kJ/mol was found at around 420 K.     

The C–HCl2Cu(II) synthon in the structural direction and assembly of supramolecular complexes with the 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine ligand and its N-substituted derivatives

Three new Cu(II) supramolecular complexes [Cu(L₁)Cl₂]·2DMF (1), [Cu(L₂)Cl₂] (2) and [Cu(L₃)Cl₂]·DMF (3) (L₁ = 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine, L₂ = 3,3′- bis(N-ethyl-2-benzimidazolyl)-2,2′-dipyridine and L₃ = 3,3′-bis(N-benzyl-2-benzimidazolyl)-2,2′-dipyridine) have been prepared and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. X-ray structural analysis of L₁, L₂·3.5H₂O and L₃·H₂O indicates that all three ligands adopt the trans conformation with the two benzimidazole fragments located on opposite sides of the dipyridyl backbone. While in complexes 1–3, all the ligands display the cis conformation and behave as bidentate chelating reagents to coordinate with Cu(II). The inorganic chloride ions always act as a reliable hydrogen bonded acceptor in these structures, and the resulting C–HCl₂Cu supramolecular synthons play a significant role in the formation and stabilization of the structures. Moreover, additional non-covalent interactions, such as C–Hπ, are also identified to extend the discrete (0-D) or low-dimensional (1-D) motifs into high-dimensional architectures.     

Nature of weak inter- and intramolecular contacts in crystals 2. Character of electron delocalization and the nature of X—H...H—X (X = C,B) contacts in the crystal of 1-phenyl-<Emphasis Type="Italic">o</Emphasis>-carborane

High-resolution single crystal X-ray study of 1-phenyl-o-carborane was carried out and the experimental and theoretical (B3LYP/6-311G** calculated) electron density distributions in the title compound were investigated. Character of electron delocalization in 1-phenyl-o-carborane was examined by analyzing the deformation electron density maps, maps of the Laplacian of the electron density, and maps of the electron localization function. Crystal-structure-forming X—H...H—X (X = C, B) intermolecular contacts were revealed and analyzed. The energies and geometric parameters of these contacts were compared with the results of quantum chemical calculations of the crystal structure and with characteristics of the same type of intramolecular contacts.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 541–552, March, 2005.     

A New Clathrate Featuring a Spiro-Type Ammonium Host. X-Ray Structure of the Inclusion Compound with Chloroform

A new onium salt host molecule 1 featuring a spiro-type ammonium backbone was synthesized and shown to form a crystalline inclusion compound with chloroform, 1 · chloroform (1:2), the crystal structure of which is reported. The host molecular interactions including C–H···Br, Cl···Cl and aromatic stacking contacts are typical of the packing structure.Supplementary Data relevant to this publication have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication No. CCDC 229358.This revised version was published online in July 2005 with a corrected issue number.