Systematic studies on the dynamics, intermolecular interactions and local structure in the alkyl and phenyl substituted butanol isomers

Supramolecular Structure of Phenyl Derivatives of Butanol Isomers

“…From our previous studies using infrared and dielectric spectroscopy, it was established that the phenyl moiety affects only slightly the degree of association and does not influence the strength of HBs in the phenyl butanols compared to their alkyl counterparts. 20 Moreover, phenyl butanols were characterized by similar values of the Kirkwood factor, which measures the long-distance correlations between the dipole moments of molecules, to those determined for their aliphatic analogues. In this context, to explain the lack of the PPs in the structure factors of the studied phenyl butanols, in the further part of the paper, the partial atomic contributions S ij ′ ( Q ) to the total S ( Q ) were examined based on the optimized models.…”

“…Therefore, based on solely experimental total S ( Q ), it is not possible to assign unambiguously the observed diffraction peaks to specific interatomic correlations. From our previous studies using infrared and dielectric spectroscopy, it was established that the phenyl moiety affects only slightly the degree of association and does not influence the strength of HBs in the phenyl butanols compared to their alkyl counterparts . Moreover, phenyl butanols were characterized by similar values of the Kirkwood factor, which measures the long-distance correlations between the dipole moments of molecules, to those determined for their aliphatic analogues.…”

“…Going back to the degree of association of molecules via H-bonds, it is worth mentioning the infrared (IR) spectroscopy results reported in our previous paper. 20 The IR spectra indicated that at room temperature, aliphatic butanols do not exhibit a signal from unbounded OH moieties while phenyl butanols exhibit a very weak peak associated with vibrations of free OH groups. The numbers of HBs determined here based on the optimized MD models with the broadest angle restriction (H–O–O angle ≤ 90°, see the Supporting Information ) best correspond to the results of the previous IR studies.…”

“…The major factors deciding their degree of association and morphology are the intramolecular architecture and the location of the OH group in relation to the carbon skeleton. 20,22 In turn, in another paper, 24 we demonstrated that the phenyl ring exerts a strong effect on the self-organization of 1-phenyl alcohols' molecules, leading to a significant decline in the size and concentration of H-bonded clusters. Furthermore, it was postulated that besides playing the role of steric hindrance, the bulky aromatic ring acts as a source of additional π•••π/OH•••π interactions affecting the supramolecular organization.…”

“…In fact, the discussions on the steric hindrance effect of molecular shape, the impact of the alkyl chain length, and the position of the OH group on the supramolecular structure in various alcohols are abundant in the literature. − However, the information on the associating phenomena of alcohols with the steric hindrance in the form of the attached phenyl group is based practically only on the dielectric and infrared spectroscopy studies and many contradictions have arisen on this topic. − First, Kalinovskaya et al and Johari et al postulated that the phenyl group in 1-phenyl-1-propanol reduces the extent of intermolecular H-bonding as the Debye-type relaxation process vanishes. Subsequently, Böhmer et al concluded that the aromatic ring only affects the supramolecular architecture of phenyl-propanols, while the structure formation through HBs is not generally suppressed by the increased steric hindrance.…”