نتایج جستجو برای: halogen bonding

تعداد نتایج: 47843  

Journal: :Dalton transactions 2016
Luca Rocchigiani Alceo Macchioni

The potential of NMR spectroscopy to investigate inorganic systems assembled by, or whose reactivity is affected by, non-covalent interactions is described. Subjects that have received particular attention in recent years (halogen bonding and Frustrated Lewis Pairs) and more classical subjects that remain under-explored (self-aggregation of ion pairs in low polar solvents, behavior of MAO conta...

Journal: :Physical chemistry chemical physics : PCCP 2016
Antonio Bauzá Antonio Frontera Tiddo J Mooibroek

The 1,1,2,2-tetracyanocyclopropane (TCCP) unit presents a synthetically accessible and versatile synthon that can interact with lone-pair or π-electrons by 'non-covalent carbon bonding'. Complexes of TCCP with common small molecules, anions, aromatics like fullerenes, amino acids and nucleobases were computed at the DFT BP86-D3/def2-TZVP level of theory. Binding energies vary between about -10 ...

Journal: :Acta crystallographica. Section C, Structural chemistry 2015
Kulsoom Kamal Hardesh K Maurya Atul Gupta Prema G Vasudev

The revived interest in halogen bonding as a tool in pharmaceutical cocrystals and drug design has indicated that cyano-halogen interactions could play an important role. The crystal structures of four closely related δ-keto esters, which differ only in the substitution at a single C atom (by H, OMe, Cl and Br), are compared, namely ethyl 2-cyano-5-oxo-5-phenyl-3-(piperidin-1-yl)pent-2-enoate, ...

2015
Joseph E. Meany Steven P. Kelley Robert M. Metzger Robin D. Rogers Stephen A. Woski

In the title compound, C14H10Br2O4, the dihedral angle between the aromatic rings is 67.29 (19)°. Both meth-oxy-group C atoms lie close to the plane of their attached ring [deviations = -0.130 (4) and 0.005 (5) Å]. In the crystal, mol-ecules pack in a centrosymmetric fashion and inter-act via a mixture of weak π-π stacking inter-actions [centroid-centoid separations = 4.044 (2) and 4.063 (3) Å]...

Journal: :Physical chemistry chemical physics : PCCP 2015
Ibon Alkorta José Elguero Otilia Mó Manuel Yáñez Janet E Del Bene

Ab initio MP2/aug'-cc-pVTZ calculations have been carried out to investigate the structures, binding energies, and bonding characteristics of binary complexes HFBe:FCl, R2Be:FCl, and FCl:N-base, and of ternary complexes HFBe:FCl:N-base and R2Be:FCl:N-base for R = H, F, Cl; N-base = NH3, NHCH2, NCH. Dramatic synergistic cooperative effects have been found between the Be···F beryllium bonds and t...

Journal: :Topics in current chemistry 2015
Michal H Kolář Palanisamy Deepa Haresh Ajani Adam Pecina Pavel Hobza

The nature of halogen bonding in 128 complexes was investigated using advanced quantum mechanical calculations. First, isolated halogen donors were studied and their σ-holes were described in terms of size and magnitude. Later, both partners in the complex were considered and their interaction was described in terms of DFT-SAPT decomposition. The whole set of complexes under study was split int...

Journal: :Organic & biomolecular chemistry 2015
Stuart P Cornes Charles H Davies David Blyghton Mark R Sambrook Paul D Beer

A rotaxane host system containing a novel halogen bonding (XB) 5-iodo-1,2,3-triazole functionalised pyridinium motif, within its axle component, has been prepared via a ring closing metathesis reaction, using chloride as a template. Proton NMR titration experiments, in competitive 1 : 1 CDCl3-CD3OD solvent media, showed the XB rotaxane selectively bound halides over larger, more basic oxoanions...

Journal: :Physical chemistry chemical physics : PCCP 2014
Sergiy V Rosokha Charlotte L Stern Alan Swartz Rory Stewart

UV-Vis measurements showed that the interaction of pseudohalide anions, A(-) (A(-) = N3(-), NCO(-), NCS(-)), with electrophilic bromocarbons, R-Br (R-Br = CBr4, CBr3NO2, CBr3CONH2, CBr3H, CBr3F, CBr3CN or C3Br2F6), in solution results in formation of [R-Br, A(-)] complexes. These associates are characterized by intense absorption bands in the 200-350 nm range showing distinct Mulliken correlati...

Journal: :Crystal Growth & Design 2023

Halogen bonding interactions of 15 crystalline 3-iodopyridinium systems were investigated. These derived from four N-alkylated salts prepared in this study. The experimental results the solid state show that halogen acts as a secondary intermolecular force these charged but sustains high directionality interaction presence other forces. bonds donated by polytopic cations are also sufficient to ...

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