Search results for "Halogen bond"

In the Pursuit of Efficient Anion-Binding Organic Ligands Based on Halogen Bonding

2013

The syntheses and the crystal structures of new multitopic anion-binding organic ligands based on a benzenoid scaffold and bearing two or three 2-iodo-imidazolium arms are reported. The quite short...

One-dimensional organization of free radicals via halogen bonding

2012

Halogen bonds have been applied for the supramolecular organization of organic free radicals in the solid state and their role in the propagation of the magnetic exchange has been studied.

Definition of the halogen bond (IUPAC Recommendations 2013)

2013

This recommendation proposes a definition for the term “halogen bond”, which designates a specific subset of the inter- and intramolecular interactions involving a halogen atom in a molecular entity.

2018

Tetrel bonding is the noncovalent interaction of group IV elements with electron donors. It is a weak, directional interaction that resembles hydrogen and halogen bonding yet remains barely explored. Herein, we present an experimental investigation of the carbon-centered, three-center, four-electron tetrel bond, [N–C–N]+, formed by capturing a carbenium ion with a bidentate Lewis base. NMR-spectroscopic, titration-calorimetric, and reaction-kinetic evidence for the existence and structure of this species is reported. The studied interaction is by far the strongest tetrel bond reported so far and is discussed in comparison with the analogous halogen bond. The necessity of the involvement of …

Breathing molecular crystals: halogen- and hydrogen-bonded porous molecular crystals with solvent induced adaptation of the nanosized channels

2012

Exceptionally strong (OC–)2N–I⋯N halogen bonding (XB) in a combination with CO⋯H–C hydrogen bonds (HB) between N-iodosuccinimide (NIS) and hexamethylenetetramine (HMTA) yielded a series of molecular crystals possessing large 1D channels. In each structure, HMTA was tetra-coordinated by four NIS molecules resulting in robust [HMTA]·[NIS]4 complexes where the observed I⋯N distances, ranging from 2.486 to 2.586 A, were remarkable shorter (from 29.6 to 26.7%) than the sum of the vdW radii of nitrogen and iodine atoms. Multiple CO⋯H–C HBs interconnected the [HMTA]·[NIS]4 complexes into the structures with flexible “breathing” host-channels. Three different host-channel structures, either oval or…

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…

NI halogen bonding supported stabilization of a discrete pseudo-linear [I12]2− polyiodide

2015

Two different dicationic N-donors, based on the DABCO diamine, have been studied as templates for polyiodides. The results present a new strategy for polyiodide stabilization, which involves both N⋯I halogen bonding and cation–anion interactions. This is highlighted by the self-assembly of an unprecedented discrete pseudo-linear dodecaiodide species.

Tunable crossover between one- and three-dimensional magnetic dynamics inCoIIsingle-chain magnets organized by halogen bonding

2016

Low-temperature magnetometry, ac susceptibility, and calorimetry have been employed to study Co-based single-chain magnets (SCMs) organized through halogen bonding. Magnetic hysteresis and maxima in the dc and ac susceptibilities, respectively, confirm the SCM behavior of the system. Several characteristic magnetic relaxation regimes are observed at different temperatures, which can be associated with both intra- and interchain exchange interactions. Remarkably, tweaking the rate at which an external magnetic field is swept along the axis of the chains enables a controlled transition between the one- and three-dimensional dynamics. Experiments on an isostructural Co-based SCM system crystal…

Azobenzene-based difunctional halogen-bond donor: Towards the engineering of photoresponsive co-crystals

2014

Halogen bonding is emerging as a powerful non-covalent interaction in the context of supramolecular photoresponsive materials design, particularly due to its high directionality. In order to obtain further insight into the solid-state features of halogen-bonded photoactive molecules, three halogen-bonded co-crystals containing an azobenzene-based difunctional halogen-bond donor molecule, (E)-bis(4-iodo-2,3,5,6-tetrafluorophenyl)diazene, C12F8I2N2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. The crystal structure of the non-iodinated homologue (E)-bis(2,3,5,6-tetrafluorophenyl)diazene, C12H2F8N2, is also reported. It is demonstrated that the stud…

The Se … Hal halogen bonding: Co-crystals of selenoureas with fluorinated organohalides

2021

Abstract Synthesis and structural characterization of binary co-crystals 1–4 is reported in the present paper. Selenourea and 1,1-dimethylselenourea were used as selenium-containing halogen bond (XB) acceptors and iodopentafluorobenzene (IPFB), 1,4-diiodotetrafluorobenzene (1,4-DIFB) and 1,4-dibromotetrafluorobenzene (1,4-DBrFB) as XB donors. A comparative analysis of the similar binary co-crystals of selenourea and thiourea with a halogen donor revealed that Se … Hal halogen bonds are up to 13.12% shorter than the sum of vdW radii, while in case of S … Hal halogen bonds this value is 11.4%. Therefore, selenium tends to form stronger bonds with halogens than sulfur does. Comparisons of XB i…