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Short X···N Halogen Bonds With Hexamethylenetetraamine as the Acceptor

2021

Hexamethylenetetramine (HMTA) and N-haloimides form two types of short (imide)X···N and X–X···N (X = Br, I) halogen bonds. Nucleophilic substitution or ligand-exchange reaction on the peripheral X of X–X···N with the chloride of N-chlorosuccinimide lead to Cl–X···N halogen-bonded complexes. The 1:1 complexation of HMTA and ICl manifests the shortest I···N halogen bond [2.272(5) Å] yet reported for an HMTA acceptor. Two halogen-bonded organic frameworks are prepared using 1:4 molar ratio of HMTA and N-bromosuccinimide, each with a distinct channel shape, one possessing oval and the other square grid. The variations in channel shapes are due to tridentate and tetradentate (imide)Br···N coordi…

116 Chemical scienceschemistry.chemical_elementHMTAN-haloimidechemistry.chemical_compoundkemialliset sidoksethalogen bond. hexamethylenetetraamine. N-haloimide.Nucleophilic substitutionsupramolekulaarinen kemiaQD1-999orgaaniset yhdisteetOriginal ResearchInterhalogenHalogen bondBrominehalogeenitChemistryhexamethylenetetraaminehalogen bond. hexamethylenetetraamine. N-haloimideGeneral ChemistryAcceptorChemistryCrystallographyCovalent bondinterhalogenHalogendihalogenhalogen bondHexamethylenetetramine

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Interaction Between Amines and N-Haloimides: a New Motif for Unprecedentedly Short Br...N and I...N Halogen Bonds

2011

The complexes of N-bromosuccinimide or N-iodosuccinimide with a halogen bond acceptor, either 1,4-diazabicyclo[2.2.2]octane (DABCO), hexamethylenetetramine (HMTA) or 1,3,5-triazine (TRZ), led to an unprecedentedly strong (CO)2N–X⋯N halogen bond synthon (X = Br or I) determined from crystal structures of [DABCO]·[NBS]22, [HMTA]·[NBS]22, [TRZ]·[NIS]22 and [HMTA]·[NIS]44. The Br⋯N distances with DABCO and with HMTA donors were 2.347 A and 2.414 A being remarkably shorter (31% and 29%) than the sum of the VDW radii of nitrogen and bromide atoms, respectively. The corresponding I⋯N distances with HMTA and TRZ were 2.549 A and 2.596 A (27.8% and 26.4% less than the sum of the VDW radii of N and I…

Halogen bondChemistryInorganic chemistrySynthonGeneral ChemistryDABCOCrystal structureCondensed Matter Physicschemistry.chemical_compoundCrystallographyBromideHalogenGeneral Materials ScienceHexamethylenetetramineAcetonitrileta116Crystal Engineering Communications

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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…

Halogen bondHydrogenChemistryHydrogen bondInorganic chemistrychemistry.chemical_elementGeneral ChemistrySolventchemistry.chemical_compoundCrystallographyHalogenMoleculeHexamethylenetetraminePorosityta116Chemical Science

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Picomolar inhibition of cholera toxin by a pentavalent ganglioside GM1os-calix[5]arene

2013

Cholera toxin (CT), the causative agent of cholera, displays a pentavalent binding domain that targets the oligosaccharide of ganglioside GM1 (GM1os) on the periphery of human abdominal epithelial cells. Here, we report the first GM1os-based CT inhibitor that matches the valency of the CT binding domain (CTB). This pentavalent inhibitor contains five GM1os moieties linked to a calix[5]arene scaffold. When evaluated by an inhibition assay, it achieved a picomolar inhibition potency (IC50 = 450 pM) for CTB. This represents a significant multivalency effect, with a relative inhibitory potency of 100000 compared to a monovalent GM1os derivative, making GM1os-calix[5]arene one of the most potent…

Models MolecularCholera ToxinbindingStereochemistrydesignCalix[5]areneEpithelial cellsG(M1) GangliosideHeat-labile enterotoxinmedicine.disease_causeligandBiochemistrycrystalMultivalency effectsCholeraCausative agentsmedicinePotencyHumansoligosaccharidePhysical and Theoretical ChemistryIC50Vibrio choleraeheat-labile enterotoxinVLAGchemistry.chemical_classificationgm1 mimicsGangliosideInhibition assaysChemistryCholera toxinOrganic ChemistryOligosaccharideBinding domainLigand (biochemistry)ValenciesOrganische ChemiehexamethylenetetramineChemistryPositive ionsaffinityAntitoxinsCalixarenesrecognitionBinding domain

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Synchrotron-based Fourier transform spectra of the ν23 and ν24 IR bands of hexamethylenetetramine C6N4H12

2015

Abstract Hexamethylenetetramine (HMT), C6N4H12 is a spherical top with nine IR-active modes. Because of its relevance for astrophysics, we recorded the absorption spectra in the full range of its fundamental bands. In total, we detected eight fundamental bands and recently published the rotational analysis of the four most intense bands ( ν 19 , ν 20 , ν 21 , ν 22 ) located in the 1000–1500 cm−1 range as a support for astronomical searches (Pirali et al., 2014). While the CH stretch modes are unresolved broad features, in this article we report the analysis of the two remaining fundamental bands exhibiting rotationally resolved structures: ν 23 –GS and ν 24 –GS located at about 820 cm−1 and…

PhysicsAbsorption spectroscopyFourier transform spectraSpectral bandsAtomic and Molecular Physics and OpticsSynchrotronlaw.inventionchemistry.chemical_compoundNuclear magnetic resonancechemistryFar infraredlawPhysical and Theoretical ChemistryHexamethylenetetramineAtomic physicsSpectroscopyJournal of Molecular Spectroscopy

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