Search results for "interactions."

The Synergetic Interplay of Weak Interactions in the Ion-Pair Recognition of Quaternary and Diquaternary Ammonium Salts by Halogenated Resorcinarenes

2013

The influence of halogens on the noncovalent interactions of different upper-rim-substituted hexylresorcinarenes with quaternary and diquaternary ammonium iodide salts was investigated in the gas phase by electrospray ionization Fourier-transform ion-cyclotron-resonance (ESI-FTICR) mass spectrometry and in solution by 1H NMR titration studies. The electronic nature of the substituents on the upper rim of the resorcinarene was directly reflected in the order of binding strengths of the hosts towards quaternary and diquaternary ammonium cations in the gas phase. In solution, the opposite trend was observed, with generally higher binding constants for the diquaternary over the quaternary salts…

Metal ion affinity-based biomolecular recognition and conjugation inside synthetic polymer nanopores modified with iron-terpyridine complexes.

2011

Here we demonstrate a novel biosensing platform for the detection of lactoferrin (LFN) via metal-organic frameworks, in which the metal ions have accessible free coordination sites for binding, inside the single conical nanopores fabricated in polymeric membrane. First, monolayer of amine-terminated terpyridine (metal-chelating ligand) is covalently immobilized on the inner walls of the nanopore via carbodiimide coupling chemistry. Second, iron-terpyridine (iron-terPy) complexes are obtained by treating the terpyridine modified-nanopores with ferrous sulfate solution. The immobilized iron-terPy complexes can be used as recognition elements to fabricate biosensing nanodevice. The working pri…

Role of C–H···Au and Aurophilic Supramolecular Interactions in Gold–Thione Complexes

2014

The role of noncovalent gold–hydrogen and aurophilic interactions in the formation of extended molecular systems of gold complexes was studied. Three new gold compounds with a heterocyclic thione ligand N-methylbenzothiazole-2-thione (mbtt), namely, [AuCl(mbtt)] (1), [AuBr(mbtt)] (2), and [Au(mbtt)2][AuI2]1–n[I3]n (3), were synthesized and characterized. The halide ligand had a considerable effect on the complex structures and thus to noncovalent contacts. Intermolecular C–H···Au and aurophilic Au···Au contacts were the dominant noncovalent interactions in structures 1–3 determining the supramolecular arrays of the gold complexes. In 1 and 2, unusual intermolecular C–H···Au gold–hydrogen co…

Discrete and 1D coordination polymeric chloro-bridged copper(II) dimers exhibiting ferro- and antiferromagnetic exchange coupling: Magneto-structural…

2009

The synthesis and characterization of two 1D coordination polymers [Cu 2 (MHL)Cl 2 ][ClO 4 ] 2  · CH 3 CN · THF ( 2  · CH 3 CN · THF) and [Cu 2 (MPyPz)Cl 2 ][ClO 4 ] 2  · CH 3 CN ( 3  · CH 3 CN), having repetitive { Cu 2 II ( μ -Cl ) 2 } units, of m -xylyl-based ligands with terminal tridentate (2-pyridyl)alkylamine (MHL = α,α′-bis[ N -(2-pyridylethyl)- N -(2-pyridylmethyl)amino]- m -xylene) and (2-pyridyl)alkylamine/pyrazole (MPyPz = α,α′-bis[ N -(2-pyridylethyl)- N -(pyrazol-1-ylmethyl)amino]- m -xylene) coordination have been accomplished. X-ray crystallographic studies reveal that the copper(II) centers in the recently reported dichloro-bridged discrete { Cu 2 II ( μ -Cl ) 2 } complex […

2-Acylamino- and 2,4-bis(acylamino)pyrimidines as supramolecular synthons analysed by multiple non-covalent interactions. DFT, X-ray diffraction, and…

2012

Intermolecular interactions of ten 2-acylamino and 2,4-bis(acylamino)pyrimidines (7 of which are previously unknown) have been investigated by X-ray structural, quantum chemical (DFT), and NMR spectral methods. Especially the concentration dependencies of the (1)H NMR chemical shifts and titrations with other molecules capable of multiple hydrogen bonding provided useful information regarding their association via triple or quadruple hydrogen bonding, which is controlled by the conformational preferences of 2-acylamino- and 2,4-bis(acylamino)pyrimidines. On comparison of the properties of 2-acylamino- and 2,4-bis(acylamino)pyrimidines with the corresponding pyridines, an additional nitrogen…

Attractive halogen···halogen interactions in crystal structure of trans-dibromogold(III) complex

2020

Abstract A synthesis of the trans-dibromogold(III) t-Bu-Xantphos complex and its self-assembly into infinite 1-dimensional chain in the solid state is reported. The new complex characterized using elemental analyses (C, H, N), ESI-MS, 1H and 13C NMR techniques and X-ray diffraction analysis. Results of DFT calculations followed by the topological analysis of the electron density distribution within the framework of QTAIM method at the ωB97XD/DZP-DKH level of theory reveal that strength of attractive intermolecular non-covalent interactions Br···Br in the crystal is 1.2–1.6 kcal/mol.

Intermolecular hydrogen bonding H···Cl in crystal structure of palladium(II)-bis(diaminocarbene) complex

2018

Abstract The reaction of bis(isocyanide)palladium complex cis-[PdCl2(CNXyl)2] (Xyl=2,6-Me2C6H3) with excess of 4,5-dichlorobenzene-1,2-amine in a C2H4Cl2/MeOH mixture affords monocationic bis(diaminocarbene) complex cis-[PdClC{(NHXyl)=NHC6H2Cl2 NH2}{C(NHXyl)=NHC6H2Cl2NH2}]Cl (3) in moderate yield (42%). Complex 3 exists in the solid phase in the H-bonded dimeric associate of two single charged organometallic cations and two chloride anions according to X-ray diffraction data. The Hirshfeld surface analysis for the X-ray structure of 3 reveals that the crystal packing is determined primarily by intermolecular contacts H–Cl, H–H, and H–C. The intermolecular hydrogen bonds N–H···Cl and C–H···C…

Structure and Chemical Bonds in Black Ti(C, N, O) Thin Films

2010

Quantitative measurements of non-covalent interactions with diamond based magnetic imaging

2018

We present a technique employing dielectrophoretic (DEP) manipulation of surface immobilized complexes integrated with a magnetic imaging platform based on nitrogen-vacancy (NV) centers in diamond for the quantitative measurements of non-covalent interactions. The interdigitated microelectrodes closely spaced to the functionalized surface of the diamond plate provide a wide range of applied DEP forces for noninvasive manipulation of various molecular interactions, while the NV layer under the surface reports the unbinding dynamics. Given that biological samples do not present significant magnetic background and do not screen magnetic fields, our approach has many advantages over the fluores…

Hydrogen-Bonded Aggregates of Oligoaramide−Poly(ethylene glycol) Block Copolymers

2010

Rod−coil copolymers with an oligomeric rod aggregate on a nanometer length scale, which is important for many applications like e.g. organic photovoltaics. However, this aggregation behavior and the driving forces such as hydrogen bonding and π−π interactions, as well as the role of side groups, are not yet fully understood. Here, we investigated these noncovalent interactions in oligo(p-benzamide)−poly(ethylene glycol) (OPBA−PEG) copolymers using solid-state NMR supported by wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and polarization optical microscopy (POM). It was found that longer OPBAs form layered β-sheet-like aggregates and that these are stabilized …