Evidence of C–H···O Interactions in the Thiophene:Water Complex

Abstract

An analysis of the 1:1 complex of thiophene and water is presented. In this study, computation and matrix isolation Fourier transform infrared spectroscopy (FTIR) were used to determine stable complexes of thiophene and water. Computational studies found six, low-energy complexes that were differentiated by the interaction present. Three complexes were characterized by C–H···O interactions, one by O–H···S, one by O–H···π, and one with an unusual, dual interaction of O–H···S and C–H···O. The O–H···π interaction was found to have the lowest overall energy at multiple levels of theory (B3LYP, B3LYP-GD3BJ, B97-D3, M05-2X, ωB97X-D, and MP2). Analysis of matrix isolation FTIR spectra indicated that the primary experimental geometry was a complex where water interacts through C–H···O at the α carbon position of the thiophene ring. This experimental result is not in line with other related complexes (furan:water and thiophene:methanol) where the complex formed through more standard interactions (e.g., O–H···O and O–H···π). These atypical differences are explored in our findings.

Thiophene‐Based Conjugated Acetylenic Polymers with Dual Active Sites for Efficient Co‐Catalyst‐Free Photoelectrochemical Water Reduction in Alkaline Medium

“…As both the 814/819 cm −1 and 933/937 cm −1 normal modes bring the C β closer to the diacetylenic moieties, we propose that the water dissociation step occurs via a six‐atom intermediate where water interacts with the sufficiently electron rich C β (H) of the outer thiophene ring. Such C−H(thiophene)⋅⋅⋅O(water) interaction (Figure S27a) was previously reported [42] to have the most preferred geometry between thiophene and water and it is here proposed to be strong enough to break the (H)O−H bond in the water molecule.…”

Stereoisomer-dependent conversion of dinaphthothienothiophene precursor films

“…5 strongly suggest intermolecular hydrogen bonding between the carbonyl and phenyl C–H groups. The C–H O interactions of aromatic C–H donors have been recognized by several experimental and computational studies 33 – 38 . Here, the shifts of both vibrational bands of the exo-isomer are larger than those of the endo-isomer.…”

Rotational analysis of naphthol-aromatic ring complexes stabilized by electrostatic and dispersion interactions

“…We observed the 1NpOH-1 water and 1NpOH-neon complexes, 29,53 however this does not account for all the unassigned transitions, which we attribute to other complexes containing water, neon, and thiophene. 54…”