Self association behaviour of α-ω diol monoalkyl ethers

Abstract

The infrared spectroscopic and thermodynamic properties of H bonding in a number of diol monoalkyl ethers RO(CH₂)_nOH and RO(CH₂)₂O(CH₂)₂OH where R = CH₃, C₂H₅ and C₄H₉ and n= 2, 3 and 4 are rationalised in terms of their conformational and self-association behaviour in solutions. The half-band width Δν½ and the apparent integrated absorption intensity B= 1/Cl∫ ln(T₀/T)νdν of the intramoleculary H bonded OH bands and the enthalpy change ΔH° involved in the equilibrium reaction intramolecularly H bonded monomer ⇌ free monomer are linearly correlated with the shift of OH frequency on intramolecular H bonding Δν(=ν_{free OH}–νH bonded OH). The nature of the self-associated species is found to depend no the stability of gauche conformations of the O(CH₂)_nO units.