N-Allyl-N-methyl-2-aminopropane (AMAP) is a relatively simple tertiary amine that has a chiral center at the pyramidal nitrogen. Racemization occurs by inversion-rotation at nitrogen. For each AMAP enantiomer, conformational exchanges occur via isolated rotation about carbon-nitrogen and carbon-carbon bonds. The 1H and 13C{1H} dynamic NMR (DNMR) spectra of AMAP show a higher temperature decoale...

An electrostatics-based approach has been proposed for probing the weak interactions between lone pair containing molecules and π deficient molecular systems. For electron-rich molecules, the negative minima in molecular electrostatic potential (MESP) topography give the location of electron localization and the MESP value at the minimum (Vmin) quantifies the electron-rich character of that reg...

Interpenetration is an intrinsic behaviour for the porous coordination networks. To prevent the interpenetration, a common strategy is the imposition of geometric or steric restrictions by incorporating bulky moieties into organic tectons. So far, most of the available incorporations have been achieved through a covalent connection, while few involved in the non-covalent weak interactions. In t...

Current limitations in protein structure prediction and design suggest an incomplete understanding of the forces governing protein folding. As such, noncovalent interactions in proteins, particularly hydrogen bonds, have received great attention [1,2]. In common secondary structure patterns like the α-helix and β-sheet, main-chain N–H hydrogen bond donors approach their carbonyl acceptors appro...

Stabilising C–Cl(lone-pair)⋯π(chelate ring) interactions are described.

We investigate the behavior of lone-pair electrons in a mixed Sb(5s)/Bi(6s) crystal-environment. Density functional theory is used to calculate electronic properties Sb-alloyed-Bi2WO6 and study effects introducing Sb 5s orbitals band structure. The edge positions, partial charge analyses, decomposed densities BiSbWO6 are explain observed trends relative stabilities shifts. To isolate role lone-...

Different structural chemistries resulting from the Pb2+ lone-pair electrons in the PbMO3 perovskites are reviewed. The Pb2+ lone-pair electrons enhance the ferroelectric transition temperature in PbTiO3, stabilize vanadyl formation in PbVO3, and induce a disproportionation reaction of CrIV in PbCrO3. A Pb2+ + NiIV = Pb4+ + NiII reaction in PbNiO3 stabilizes the LiNbO3 structure at ambient pres...

Density functional theory methods(DFT) and natural bond orbital (NBO) analysis were used to investigate the effects of isomerism and side chain mutation at a microscopic level on the stability, binding energy and NMR/NQR tensors of structural isomers, L- methionylasparagine (Met-Asn) and L- asparagylmethionine (Asn-Met) in the gas phase. The results represented that the isomerism and side chain...

Quantum-chemical calculations were used to investigate molecular and electronic properties of porphyrin and subporphyrin. Their basicities were estimated in ground and excited states. It was found that multiple proton nitrogen lone-pair coordination plays an important role in acid/base properties of the studied molecules. Lone pair-lone pair interactions in didehydroporphyrin and energetic stab...