Intermolecular noncovalent interactions with carbon in solution

Abstract

One of the most familiar carbon-centered noncovalent interactions (NCIs) involving antibonding π*-orbital situated at the Bürgi-Dunitz angle from the electron donor, mostly lone pairs of electrons, is known as n→π*...

Intermolecular n→π* Interactions in Supramolecular Chemistry and Catalysis

“…Biswal and coworkers [32] set up a method of spectroscopy (IR and NMR) aided with molecular dynamics (MD) simulation and DFT calculations to study the intermolecular n!π* interactions in solution, choosing 3,3-dimethyltetracyanocyclopropane as the electronic acceptor and pyridine 1-oxide as the nucleophile (donor). The MD simulations provided significant region of the peak corresponding to short O•••C distance (2.93~3.12 Å, within the sum of van der Waals radii) between the N atom of donor and carbon of cyano group, and observation of ffO•••C � N ranging from 107°~114°(Figure 19).…”

N···C═O n → π* Interaction: Gas-Phase Electronic and Vibrational Spectroscopy Combined with Quantum Chemistry Calculations

“…Maciel and co-workers as well as Rademacher and co-workers measured 13 C NMR spectra by probing the carbonyl carbon of a series of cyclic aminoketones having transannular N···CO n → π* interaction. − Raines and co-workers showed the presence of the CO···CO n → π* interaction by measuring the equilibrium constant for the interconversion of the cis and trans conformers of N -formyl- l -proline methyl ester through 1 H NMR spectroscopy . Recently, Biswal and co-workers utilized 13 C NMR spectroscopy to demonstrate the presence of O···CN n → π* interaction in the complex of pyridine-N-oxide···dimethyltetracyanocyclopropane by probing the chemical shift of the nitrile carbon atom as a function of temperature as well as the concentration of pyridine-N-oxide …”

“…19 Recently, Biswal and co-workers utilized 13 C NMR spectroscopy to demonstrate the presence of O•••C�N n → π* interaction in the complex of pyridine-N-oxide•••dimethyltetracyanocyclopropane by probing the chemical shift of the nitrile carbon atom as a function of temperature as well as the concentration of pyridine-N-oxide. 39 T h i s c o n t e n t i s ■ EXPERIMENTAL AND COMPUTATIONAL METHODS Experimental Details. The experiments were performed using our home-built resonantly enhanced multiphoton ionization time-of-flight mass spectrometer (REMPI-TOF-MS).…”

Engineering supramolecular helical assemblies via interplay between carbon(sp) tetrel and halogen bonding interactions

“…[32][33][34] However, carbon is abundant in nature and the carbon-centered tetrel bond plays a significant role in chemical reactions and in biology. [35][36][37] The carbon tetrel bond can be constructed with sp-(C sp ), [38][39][40] sp 2 -(C sp2 ), 41,42 and sp 3 -(C sp3 ) 17,[43][44][45][46][47][48][49] hybridized carbons. Among these hybridized carbons, the C sp -tetrel bonding, though possesses the most approachable s-hole on carbon, is scarce and remains barely explored.…”