Hydrogen bond complexation of ethanol with chlorobenzene: FTIR studies

ABSTRACT

FTIR spectral studies has been carried out on ethanol (EtOH), chlorobenzene (PhCl) and their binary solutions at various EtOH/PhCl mole fractions. The bonded $\mathit{O}-\mathit{H}$ stretching region has been deconvoluted into four Gaussian peaks centring at 3543.6, 3489.4, 3406.3 and 3254.3 cm⁻¹. The first and the last peaks have been assigned to the hydroxyl stretching bands of dimer and tetramer, while the remaining two to the trimer bands. The presence of dimer in liquid PhCl has been confirmed by the experimental $\mathit{C}-\mathit{Cl}$ stretching bands. Experimentally, two $\mathit{C}-\mathit{Cl}$ stretching bands have been observed, which fall outside the 1096–1089 cm⁻¹ range reported for chlorobenzenes in literature. The positional changes in $\mathit{O}-\mathit{H}$, $\mathit{C}{H}_3$, $\mathit{C}{H}_2$, $\mathit{C}-\mathit{H}$ and $\mathit{C}-\mathit{Cl}$ stretching bands in the spectrum of the solutions have been analysed in terms of heteromolecular H-bond interactions. This analysis shows that the classical $\mathit{O}-\mathit{H}\cdots \mathit{Cl}$ hydrogen bonds are the dominant interaction forces.

KEYWORDS:

• FTIR
• H-bond interactions
• ethanol multimers

Disclosure statement

No potential conflict of interest was reported by the author(s).