Search results for " bonding"
showing 10 items of 934 documents
The first catalytic method for Heck alkynylation of unactivated aryl bromides (copper-free Sonogashira) in an ionic liquid: 1 mol-percent palladium/t…
2007
Herein we report the studies of Heck alkynylation (copper-free Sonogashira) with aryl halides (I, Br, Cl) employing various metallic precursors, tertiary phosphanes and bases in [BMIM][BF4] as the solvent. As a result, we provide the first method that allows the coupling of a large array of substrates, either activated or deactivated bromides in an ionic liquid. Furthermore, the system of highest efficiency is unexpectedly the simplest and cheaper combination that employs [Pd(η3-C3H5)Cl]2/PPh3 at only a 1 mol-% loading with pyrrolidine as the base and in the absence of a copper salt. The coupling of sterically and electronically deactivated bromides bearing different functional groups to ar…
The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts
2010
The series of haloanilinium and halopyridinium salts: 4-IPhNH₃Cl (1), 4-IPhNH₃Br (5), 4-IPhNH₃H₂PO₄ (6), 4-ClPhNH₃H₂PO₄ (8), 3-IPyBnCl (9), 3-IPyHCl (10) and 3-IPyH-5NIPA (3-iodopyridinium 5-nitroisophthalate, 13), where hydrogen or/and halogen bonding represents the most relevant non-covalent interactions, has been prepared and characterized by single crystal X-ray diffraction. This series was further complemented by extracting some relevant crystal structures: 4-BrPhNH3Cl (2, CCDC ref. code TAWRAL), 4-ClPhNH3Cl (3, CURGOL), 4-FPhNH3Cl (4, ANLCLA), 4-BrPhNH3H2PO4, (7, UGISEI), 3-BrPyHCl, (11, CIHBAX) and 3-ClPyHCl, (12, VOQMUJ) from Cambridge Structural Database for sake of comparison. Bas…
catena-Poly[[diaquabis[1,4-bis(pyridin-4-yl)buta-1,3-diyne-κN]iron(II)]-μ-cyanido-κ2N:C-[dicyanido-κ2C-platinum(II)]-μ-cyanido-κ2C:N]
2017
The molecular structure of the title compound, [FePt(CN)4(C14H8N2)2(H2O)2]n, consists of one-dimensional polymeric [–Fe–NC–Pt(CN)2–CN–]∞chains. Two water molecules and two monodentate 1,4-bis(pyridin-4-yl)buta-1,3-diyne (bpb) ligand molecules complete the octahedral coordination sphere of the FeIIatoms. The Fe—N(py) bond length (py is pyridine) is 2.2700 (15) Å, Fe—N(cyanide) is 2.1185 (16) Å and the Fe—O distance is 2.1275 (14) Å. The water molecules are hydrogen bonded to either bpb ligands or cyanide groups of the planar [Pt(CN)4]2−anion of adjacent polymeric chains. These O—H...N hydrogen bonds, in conjunction with offset and tilted π–π stacking interactions between bpb ligands and cyan…
Crystal structure ofS-octyl (E)-3-(4-methoxybenzylidene)dithiocarbazate
2015
As already observed in similar molecules, the dithiocarbazate group in the title compound, C17H26N2OS2, adopts anEEconfiguration with respect to the C=N bond of the benzylidene moiety. In the crystal, molecules are connected into inversion dimers by pairs of N—H...S hydrogen bonds. The dimers are linked by weak π–π interactions, with centroid-to-centroid distances of 3.723 (11) Å, forming chains parallel to [110].
Crystal structure of (E)-4-[N-(7-methyl-2-phenyl-imidazo[1,2-a]pyridin-3-yl)carboximido-yl]phenol.
2015
The molecule of the title compound, C21H17N3O, is built up from fused five- and six-membered rings connected to a methyl group, a phenyl ring and an (iminomethyl)phenol group. The fused ring system is almost planar (r.m.s. deviation = 0.031 Å) and forms dihedral angles of 64.97 (7) and 18.52 (6)° with the phenyl ring and the (iminomethyl)phenol group, respectively. In the crystal, centrosymmetric molecules are linked by pairs of C—H...π interactions into dimeric units, which are further connected by O–H...N hydrogen bonds to form layers parallel to (101).
Crystal structure of 4-{2-[4-(dimethylamino)phenyl]diazen-1-yl}-1-methylpyridinium iodide
2015
The molecular geometry of the ionic title compound, C14H17N4+·I−or DAZOP+·I−, is essentially featureless. Regarding the crystal structure, in addition to the obvious cation–anion Coulombic interactions, the packing is mostly directed by non-covalent interactions involving both ring systems, as well as the iodide anion. It consists of cationic molecules aligned along [101] and disposed in an antiparallel fashion while linked into π-bonded dimeric entities by a stacking contact involving symmetry-related phenyl rings, with a centroid–centroid distance of 3.468 (3) Å and a slippage of 0.951 Å. The dimers are, in addition, sustained by a number of C—H...I and I...π (I...centroid = 3.876 Å) inte…
Crystal structure of bis-(azido-κN)bis[2,5-bis(pyridin-2-yl)-1,3,4-thia-diazole-κ(2) N (2),N (3)]cobalt(II).
2015
The structure of the title compound is isotypic with that of the analogous nickel(II) complex, in which the CoN6 core shows an axially weakly compressed octahedral geometry as opposed to the almost regular geometry exhibited by the NiN6 octahedron.
Crystal structure of the diglycidyl ether of eugenol
2017
The diepoxy monomer (DGE-Eu) was synthesized from eugenol by a three-step reaction. It consists of a 1,2,4-trisubstituted benzene ring substituted by diglycidyl ether, a methoxy group and a methyloxirane group. The three-membered oxirane rings are inclined to the benzene ring by 61.0 (3) and 27.9 (3)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming layers parallel to the ab plane.
Crystal structure of 3-mesityl-1-[(pyridin-2-yl)methyl]-3,4,5,6-tetrahydropyrimidin-1-ium bromide monohydrate
2015
In the title hydrated salt, C19H24N3+·Br−·H2O, the values of the N—C bond lengths within the tetrahydropyrimidinium ring indicate delocalization of the N=C double bond. In the cation, the dihedral angle formed by the pyridine and benzene rings is 14.97 (12)°. In the crystal, ions and water molecules are linked by O—H...Br, O—H...N, C—H...Br and C—H...O hydrogen bonds into chains running parallel to thebaxis.
Crystal structures of organoplatinum complexes containing alkyleugenoxyacetate and p-chloroaniline
2016
In the title trans-dichloridoplatinum(II) complexes, the central PtII atom is further coordinated by the p-chloroaniline N atom and ethylenic double bond of alkyleugenoxyacetate.