Face, Notch, or Edge? Intermolecular dissociation energies of 1-naphthol complexes with linear molecules

Abstract

The stimulated-emission-pumping/resonant 2-photon ionization (SEP-R2PI) method was used to determine the intermolecular dissociation energies D 0 of jet-cooled 1-naphthol(1NpOH)⋅S complexes, where S is a linear molecule (N 2 , CO, CO 2 , OCS, N 2 O, and ethyne) or symmetrictop molecule (2-butyne) that contains double or triple bonds. The dissociation energies D 0 (S 0 ) are bracketed as follows: 6.68 ± 0.08 kJ/mol for S= =N 2 , 7.7 ± 0.8 kJ/mol for CO, 12.07 ± 0.10 kJ/mol for CO 2 , 13.03 ± 0.01 kJ/mol for N 2 O, 14.34 ± 0.08 kJ/mol for ethyne, 15.0 ± 1.35 kJ/mol for OCS, and 29.6 ± 2.4 kJ/mol for 2-butyne. The minimum-energy structures, vibrational wavenumbers, and zero-point vibrational energies were calculated using the dispersion-corrected density functional theory methods such as B97-D3 and B3LYP-D3 with the def2-QZVPP basis set. These predict that N 2 and CO are dispersively bound Face complexes (S bound to a naphthalene Face), while CO 2 , N 2 O, and OCS adsorb into the "Notch" between the naphthyl and OH groups; these are denoted as Notch complexes. Ethyne and 2-butyne form Edge complexes involving H-bonds from the − −OH group of 1NpOH to the center of the molecule. The presence of a double or triple bond or an aromatic C= =C bond within S does not lead to a specific calculated geometry (Face, Notch or Edge). However, a correlation exists between the structure and the sign of the quadrupole moment component Θzz of S: negative Θzz correlates with Face or Notch, while positive Θzz correlates with Edge geometries.

Soft experimental constraints for soft interactions: a spectroscopic benchmark data set for weak and strong hydrogen bonds

“…ENCH relies on experimentalists providing more reference data for its molecular entries 14,40,107 and on computational chemists adding quantum chemical models to its performance tables. [6][7][8]12,60,92 In particular, an investigation of the current 51 data entries at the highest consistently affordable wave function theory level would be instructive to test the degree of realism of the back-correction rules in a more rigorous way.…”

“…Experimental benchmark data sets offer alternatives. 13,14 They have to make educated selections in the chemical space and in the space of observables, to be practical. Furthermore, they should offer back-correction to easily computable equilibrium and harmonically evaluated quantities to be applicable without major computational barriers.…”

Structural study of 1- and 2-naphthol: new insights into the non-covalent H–H interaction in cis-1-naphthol

“…About 3.8 M (850 k) FIDs were averaged and then Fourier transformed to generate the broadband rotational spectrum for 1-naphthol (2-naphthol). 3.8 M averages were necessary to measure 13 C transition for the cis-1-naphthol conformer with sufficient signal to noise ratio.…”

“…The Leutwyler group in particular has studied 1-naphthol-(H 2 O) N (N = 1 to 50) 4 and 2-naphthol-(NH 3 ) N (N = 1-10) 5 complexes and clusters with laser spectroscopic techniques in an effort to determine the solvation threshold for excited state proton transfer from naphthol to water, 1-naphtholalkane complexes, [6][7][8] 1-naphthol-rare gas and N 2 complexes, 9 hydrogen-bonded complexes of naphthol, [10][11][12] and most recently complexes of 1-naphthol with linear molecules. 13 Naphthol-water clusters have also been studied by the Fujii group, 14 by Knochenmuss and Smith, 15 and by Pratt et al 16 The 1-naphthol dimer has been studied by infrared dip spectroscopy 17 and more recently the microwave spectrum of the 1-naphthol dimer has been measured, assigned, and interpreted, with the help of theoretical calculations, in terms of a structure that is dominated by p-p stacking interactions over canonical hydrogen bonding. 18 There are a number of earlier spectroscopic studies of the naphthol monomers.…”

“…Here, we describe the rotational spectrum of trans-2naphthol measured with a chirped-pulse Fourier transform microwave spectrometer in the 2 to 6 GHz range. Spectra of all singly substituted 13 C isotopologues were also recorded, in addition to those of cis-and trans-1-naphthol and cis-2naphthol. The isotopic data were used to derive heavy atom Kraitchman substitution coordinates 28 and semi-experimental structures for both conformers of both isomers.…”