The Structure of 2,6-Di-tert-butylphenol–Argon by Rotational Spectroscopy

Abstract

The molecular structure of a van der Waals-bonded complex involving 2,6-di-tert-butylphenol and a single argon atom has been determined through rotational spectroscopy. The experimentally derived structural parameters were compared to the outcomes of quantum chemical calculations that can accurately account for dispersive interactions in the cluster. The findings revealed a π-bound configuration for the complex, with the argon atom engaging the aromatic ring. The microwave spectrum reveals both fine and hyperfine tunneling components. The main spectral doubling is evident as two distinct clusters of lines, with an approximate separation of 179 MHz, attributed to the torsional motion associated with the hydroxyl group. Additionally, each component of this doublet further splits into three components, each with separations measuring less than 1 MHz. Investigation into intramolecular dynamics using a one-dimensional flexible model suggests that the main tunneling phenomenon originates from equivalent positions of the hydroxyl group. A double-minimum potential function with a barrier of 1000 (100) cm−1 effectively describes this extensive amplitude motion. However, the three-fold fine structure, potentially linked to internal motions within the tert-butyl group, requires additional scrutiny for a comprehensive understanding.

A Rotational Study of 2‐tert‐Butylphenol and Its 1 : 1 Argon Complex

“…The same kind of splitting was then observed in the 26BP•••argon complex. [12] The analysis of the rotational spectrum of the monomer complexed with argon revealed that breaking the symmetry on a plane perpendicular to the ring did not modify the observed splittings, confirming the nature of the hydroxyl group motion toward the two tert-butyl groups. However, it did not provide additional information on the origin of the fine splitting.…”

Easy-to-Use Chemiluminescent-Based Assay for a Rapid and Low-Cost Evaluation of the Antioxidant Activity of Cosmetic Products

“…Cosmetics analysis represents a rapidly expanding field of analytical chemistry, as new cosmetic formulations are increasingly in demand on the market and the ingredients required for their production are constantly evolving. In particular, the addition of antioxidants, which are well established in food, beverages, and pharmaceuticals, is becoming increasingly popular in cosmetic preparations, where they can serve as active ingredients, supplements, and stabilizers [1][2][3][4][5][6]. Indeed, their ability to scavenge free radicals provides anti-aging, photoprotective, antimicrobial, and anti-inflammatory action, along with protection against oxidative degradation of product components, such as lipid rancidity [1].…”