Hydrogen Bonding in Phenol, Water, and Phenol−Water Clusters

Abstract

Structure, stability, and hydrogen-bonding interaction in phenol, water, and phenol-water clusters have been investigated using ab initio and density functional theoretical (DFT) methods and using various topological features of electron density. Calculated interaction energies at MP2/6-31G level for clusters with similar hydrogen-bonding pattern reveal that intermolecular interaction in phenol clusters is slightly stronger than in water clusters. However, fusion of phenol and water clusters leads to stability that is akin to that of H(2)O clusters. The presence of hydrogen bond critical points (HBCP) and the values of rho(r(c)) and nabla(2)rho(r(c)) at the HBCPs provide an insight into the nature of closed shell interaction in hydrogen-bonded clusters. It is shown that the calculated values of total rho(r(c)) and nabla(2)rho(r(c)) of all the clusters vary linearly with the interaction energy.

Vibrational population relaxation of hydrogen-bonded phenol complexes in solution: Investigation by ultrafast infrared pump–probe spectroscopy

“…In the gas phase, the d-type OH band has a lower frequency than that of the c-type. These trends are in qualitative agreement with the results obtained from ab initio calculations for phenol clusters [44]. Based on the above observations, we proposed that the band at 3350 cm À1 was due to the d-type OH stretching mode, while the band at 3480 cm À1 was the ctype.…”

Cation–π and anion–π interactions

“…For instance, it is well known that H‐bonding shows a highly cooperative behavior. In general, the cumulative strength of networks of H‐bonds is larger than the sum of the individual bond strengths when they work simultaneously 87–90. Similar observations have been made for the interplay between stacking and H‐bonding interactions 91.…”

A new thermoresponsive polymer of poly(N-acryloylsarcosine methyl ester) with a tunable LCST

“…Similarly, phenol (pK a = 9.99), which is more acidic than water (pK a = 15.74), also can break the water molecule layer around the amide pendants. [67][68][69] In short, we suggest a mechanism as shown in Scheme 4 to understand the influence of urea exerting on the solubility of PNASME. That is, urea molecules break the water molecule layer around the polymer chains firstly, and then bind to the amide groups and ester groups as shown in Scheme 4.…”