Nature of One-Dimensional Short Hydrogen Bonding:  Bond Distances, Bond Energies, and Solvent Effects

Abstract

On the basis of recently synthesized calix[4]hydroquinone (CHQ) nanotubes which were self-assembled with infinitely long one-dimensional (1-D) short hydrogen bonds (SHB), we have investigated the nature of 1-D SHB using first-principles calculations for all the systems including the solvent water. The H-bonds relay (i.e., contiguous H-bonds) effect in CHQs shortens the H...O bond distances significantly (by more than 0.2 A) and increases the bond dissociation energy to a large extent (by more than approximately 4 kcal/mol) due to the highly enhanced polarization effect along the H-bond relay chain. The H-bonds relay effect shows a large increase in the chemical shift associated with the SHB. The average binding energies for the infinite 1-D H-bond arrays of dioles and dions increase by approximately 4 and approximately 9 kcal/mol per H-bond, respectively. The solvent effect (due to nonbridging water molecules) has been studied by explicitly adding water molecules in the CHQ tube crystals. This effect is found to be small with slight weakening of the SHB strength; the H...O bond distance increases only by 0.02 A, and the average binding energy decreases by approximately 1 kcal/mol per H-bond. All these results based on the first-principles calculations are the first detailed analysis of energy gain by SHB and energy loss by solvent effect, based on a partitioning scheme of the interaction energy components. These reliable results elucidate not only the self-assembly phenomena based on the H-bond relay but also the solvent effect on the SHB strength.

Theoretical Investigation of Normal to Strong Hydrogen Bonds

“…6) [35]. We have optimized the geometries on the plane up to the decamer at the B3LYP/6-31G * level, and up to hexamer at the MP2/6-31G * level.…”

Wagging motion of hydrogen-bonded wire in the excited-state multiple proton transfer process of 7-hydroxyquinoline·(NH3)3 cluster

“…Therefore, the nature of hydrogen bond in solution is of particular interest and has been investigated extensively by various experimental and theoretical methods [6][7][8][9][10][11]. However, little is known about electronic excited-state hydrogen bond, because the structure and dynamics of which are difficult to analyze for both theoretical and experimental studies.…”

Excited-State Proton Transfer via Hydrogen-Bonded Acetic Acid (AcOH) Wire for 6-Hydroxyquinoline

“…[1][2][3][4] As the important role of hydrogen bonds playing in physics, chemistry, and biology has been recognized, [5][6][7][8][9][10][11][12][13][14][15][16][17][18] the proton transfer along hydrogen bonding has been given more and more attention in recent years. [19][20][21][22][23][24][25] This is especially true for photoacids, where a well-defined zero-point of time for the proton-transfer reaction due to the acidity of photoacids can be switched by optical excitation.…”