1546. To William Michael Rossetti (15 December 1874)

Proton Tunneling In 5‐Chlorotropolone‐M1 (M = Kr, Xe, CH4) Van Der Waals Complexes

“…This difference might be related to the shape of the potential function along the y axis. As discussed previously, the potential functions for 5CTR-Rgt (Rg Kr, Xe) along the y axis are more symmetric than those for TRN-Rg (Rg Kr, Xe) 2. Since the y axis is not exactly parallel to the C2 axis of TRN, the change of the equilibrium position may induce asymmetry in the double-minimum potential well along the proton transfer coordinate in the case of the excitation of byo in TRN(OD)-Kr and TRN(OD)-Xel.It should be noted that A'o A"ol of 5CTR(OH)-(CH4) is remarkably smaller than that of 5CTR(OH).…”

“…The red-shift of 5CTR(OH)-Kr is similar to that of 72.2 cm of TRN(OH)-Kr, indicating that the structure of 5CTR(OH)-Kr is very similar to that of TRN(OH)-Kr in which the Rg atom attaches to the seven-membered ring in the TRN-Rg complexes. 2 The transitions marked with asterisks are assigned as hot bands of 5CTR(OH), because these transitions appear without introducing Kr. The lower frequency hot band and the higher frequency one are assigned to the 251 and 267 transitions, respectively, from the v25 and V26 frequencies in $1 and So o22, 25 Several low frequency transitions in Figure 1 must be due to vdW vibrations, because these transitions have not been observed in the fluorescence excitation spectrum of 5CTR(OH).…”

“…In Figure 11, a good linear correlation exists between the spectral red-shift and the polarizability of M. The binding energy of the complex involving a polar molecule is expressed by the sum of the dispersive and inductive interactions. 2 The strength of these interactions increases in proportion to the polarizability of M. The permanent dipole moment of TRN(OH) is u (So) 3.53 D, 26 where the MOPAC package (Ver. 6.01) furnished by Japanese Chemistry Exchange was used.…”

“…Previously, we reported preliminary results on the S-So fluorescence excitation spectra of the TRN(OH)-Rg (Rg Ar, Kr, Xe) vdW complexes and their OD derivatives in the region near the electronic origin. 2 Intermolecular vibrations were observed in these spectra and the assignments of transitions were given. The H/D isotope effect on the vibrational frequencies and the temperature dependence of vibrational distribution provided unambiguous assignments of the tunneling splittings.…”

“…7-The changes in the tunneling splittings of vibronic states of vdW clusters compared to those of the bare molecule may provide additional information about the intermolecular interactions, which have not been obtained from various vdW complexes of the aromatic molecules. 2 Intermolecular vdW vibrations have been measured in pdFB-Ar, 3,4 benzene-M (M Ar, H20, CH4, NH3), 5 aniline-Ar, 6 chlorobenzene-Ar, 6 phenol-Ar, 6 fluorobenzene-Ar, 6 s-tetrazine-Ar, v aniline-Rg (Ar, Kr, Xe), 8 phenol-Rg, 8 chlorobenzene-Rg, 8 toluene-Rg, 8 s-tetrazine-Rg, 9 and carbazole-Kr. 2 Direct data obtained from the electronic spectra of these molecules are intermolecular frequencies and spectral shifts of the origin band relative to the bare molecule.…”