CH/π hydrogen bonds in organic and organometallic chemistry

“…The weakest H-bonding interactions are established between weakly polarized D-H bonds (e.g., aliphatic CH) and mildly electron-rich H-acceptor moieties (e.g., alkene π-electrons) [21][22][23]. While a single interaction is energetically insignificant, when several weak H-bonds coexist they can stabilize protein structures [24][25][26] and contribute to the binding of proteins to carbohydrates [27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

RCH3···O Interactions in Biological Systems: Are They Trifurcated H-Bonds or Noncovalent Carbon Bonds?

Bauzá

Frontera

2016

Crystals

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Abstract:In this manuscript, we combine high-level ab initio calculations on some model systems (XCH 3 σ-hole/H-bond donors) and a Protein Data Bank (PDB) survey to distinguish between trifurcated H-bonds and noncovalent carbon bonds in XCH 3¨¨¨O complexes (X = any atom or group). Recently, it has been demonstrated both experimentally and theoretically the importance of noncovalent carbon bonds in the solid state. When an electron-rich atom interacts with a methyl group, the role of the methyl group is commonly viewed as a weak H-bond donor. However, if the electron-rich atom is located equidistant from the three H atoms, the directionality of each individual H-bond in the trifurcated binding mode is poor. Therefore, the XCH 3¨¨¨O interaction could be also defined as a tetrel bond (C¨¨¨O interaction). In this manuscript, we shed light into this matter and demonstrate the importance of XCH 3¨¨¨O noncovalent carbon bonding interactions in two relevant protein-substrate complexes retrieved from the PDB.

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“…3) reveals stacking-like packing of molecules with a lateral displacement of consecutive molecules, indicating that the crystal structure lacks π···π arene interactions. Molecular association is restricted to only one weak hydrogen bond [C(8)-H(8A)···O(2) 2.61Å, 137 • ] and C-H···π(arene) interactions [36]. The inclination between molecules of adjacent stacks indicates that the crystal structure of 1b is stabilised by van der Waals forces and close packing of molecules rather than by directed non-covalent bonding.…”

Section: Crystal Structures Of 1a and 1bmentioning

confidence: 99%

Synthesis and Structural Characterisation of New Bifunctional o-Hydroxyacetophenones – Potential Linker Molecules for Coordinative Framework Construction

Hübscher

Günthel

Rosin

et al. 2013

Zeitschrift Für Naturforschung B

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Two new linker-type molecules 1a and 1b composed of o-hydroxyacetophenone coordinative groups attached to linear ethynylene or 1,4-phenylenediethynylene spacer units have been synthesised and structurally characterised. An X-ray crystallographic study for both compounds has shown structures with strong intramolecular hydrogen bonds fitting in the model of 'Intramolecular Resonance Assisted Hydrogen Bond (IRHAB)'. Initial coordination experiments with Cu(II) were performed and the resulting materials characterised by PXRD. The similarity of the copper coordination between these compounds and copper(II) acetylacetonate complexes was demonstrated by XPS measurements. Based on the evidence of these studies, and on elemental analysis, the formation of the corresponding coordination polymers comprising Cu(II) and the linkers has been proposed.

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CH/π hydrogen bonds in organic and organometallic chemistry

Cited by 529 publications

References 529 publications

Concentration dependent tautomerism in green [Cu(HL1)(L2)] and brown [Cu(L1)(HL2)] with H2L1 = (E)-N′-(2-hydroxy-3-methoxybenzylidene)benzoylhydrazone and HL2 = pyridine-4-carboxylic (isonicotinic) acid

Concentration dependent tautomerism in green [Cu(HL1)(L2)] and brown [Cu(L1)(HL2)] with H2L1 = (E)-N′-(2-hydroxy-3-methoxybenzylidene)benzoylhydrazone and HL2 = pyridine-4-carboxylic (isonicotinic) acid

RCH3···O Interactions in Biological Systems: Are They Trifurcated H-Bonds or Noncovalent Carbon Bonds?

Synthesis and Structural Characterisation of New Bifunctional o-Hydroxyacetophenones – Potential Linker Molecules for Coordinative Framework Construction

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