نتایج جستجو برای: halogen π

تعداد نتایج: 37828  

2014
Yoshinobu Ishikawa

In the title compound, C11H7ClO3, a chlorinated and methyl-ated 3-formyl-chromone derivative, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.0670 Å), with the largest deviation from the least-squares plane [0.2349 (17) Å] being for the pyran carbonyl O atom. In the crystal, mol-ecules are linked through π-π stacking inter-actions along the a axis [centroid-centroid distance betw...

Journal: :Acta crystallographica. Section C, Structural chemistry 2017
Chideraa I Nwachukwu Nathan P Bowling Eric Bosch

Halogen bonding is a well-established and intensively studied intermolecular interaction that has also been used in the preparation of functional materials. While polyfluoroiodo- and polyfluorobromobenzenes have been widely used as aromatic halogen-bond donors, there have been very few studies of iodoimidazoles with regard to halogen bonding. We describe here the X-ray structures of three iodoi...

Journal: :Physical chemistry chemical physics : PCCP 2016
Vincent de Paul N Nziko Steve Scheiner

In addition to the standard halogen bond formed when NH3 approaches XCN (X = F, Cl, Br, I) along its molecular axis, a perpendicular approach is also possible, toward a π-hole that is present above the X-C bond. MP2/aug-cc-pVDZ calculations indicate the latter geometry is favored for X = F, and the σ-hole structure is preferred for the heavier halogens. The π-hole structure is stabilized by cha...

Journal: :ChemistrySelect 2021

Hydrogen and halogen bonds are important anisotropic attractive interactions in the molecular crystalline state. 2,6-dibromophenol (1) was analyzed by single-crystal X-ray diffraction for first time. The intermolecular interaction pattern studied Hirshfeld surface analysis along with 2D fingerprint diagrams. characteristic that dominate crystal packing electrostatic type-II Br⋅⋅⋅Br interactions...

2009
Graeme J. Gainsford Jennifer M. Mason Shivali A. Gulab

The title compound, C(14)H(11)BrClN(3)O, crystallizes with two independent mol-ecules in the asymmetric unit. In the crystal, the molecules are linked by C-N⋯Br halogen bonds, as well as weak methyl-ene C-H⋯π, phenyl C-H⋯π, C-H⋯Br and phenyl C-H⋯O(ether) inter-actions.

2015
Yoshinobu Ishikawa

In the title compound, C10H4Cl2O3, a dichlorinated 3-formyl-chromone derivative, the fused-ring system is slightly puckered [dihedral angle between the benzene and pyran rings = 3.66 (10)°]. The dihedral angle between the pyran ring and the formyl plane is 8.64 (7)°. In the crystal, mol-ecules are linked through π-π stacking inter-actions [centroid-centroid distance between the benzene and pyra...

2016
Anna-Carin C. Carlsson Krenare Mehmeti Martin Uhrbom Alavi Karim Michele Bedin Rakesh Puttreddy Roland Kleinmaier Alexei A. Neverov Bijan Nekoueishahraki Jürgen Gräfenstein Kari Rissanen Máté Erdélyi

We have investigated the influence of electron density on the three-center [N-I-N](+) halogen bond. A series of [bis(pyridine)iodine](+) and [1,2-bis((pyridine-2-ylethynyl)benzene)iodine](+) BF4(-) complexes substituted with electron withdrawing and donating functionalities in the para-position of their pyridine nitrogen were synthesized and studied by spectroscopic and computational methods. T...

2016
Jamie R. Kerr Laurent Trembleau John M. D. Storey James L. Wardell William T. A. Harrison

We describe the syntheses and crystal structures of two indole derivatives, namely a second monoclinic polymorph of ethyl 5-chloro-1H-indole-2-carboxyl-ate C11H10ClNO2, (I), and ethyl 5-chloro-3-iodo-1H-indole-2-carboxyl-ate, C11H9ClINO2, (II). In their crystal structures, both compounds form inversion dimers linked by pairs of N-H⋯O hydrogen bonds, which generate R 2 (2)(10) loops. The dimers ...

2015
Enzo Cadoni Giulio Ferino Patrizia Pitzanti Francesco Secci Claudia Fattuoni Francesco Nicolò Giuseppe Bruno

The aim of this study is to describe and compare the supramolecular interactions, in the solid state, of chloro-, bromo-, and iodobenzothiophene diols. The compounds were obtained through organo-catalyzed reactions starting from 3-substituted halobenzothiophene carbaldehydes. Energies of the noncovalent interactions were obtained by density functional theory calculations. Bond distances and ang...

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