Rotational spectrum, structure, and intramolecular force field of the ArClCN van der Waals complex

Abstract

The rotational spectrum of the ArClCN van der Waals complex has been assigned using pulsed Fourier transform microwave spectroscopy in a Fabry-Perot cavity with a pulsed supersonic nozzle as the molecular source. ArClCN is T-shaped and the data were fit to the Watson rotational parameters and an exact expression for the Cl and N nuclear quadrupole coupling. The spectroscopic constants for Ar35ClCN are A′′ = 6152.5411(21) MHz, B′′ = 1577.0362(8) MHz, C′′ = 1246.7514(6) MHz, τ1 = −576.0(2) kHz, τ2 = −97.28(8) kHz, τaaaa = −234.8(17) kHz, τbbbb = −55.97(10) kHz, τcccc = −21.60(7) kHz, χClaa = 37.9468(23) MHz, χClbb = −79.5239(20) MHz, χNaa = 1.6403(22) MHz, and χNbb = −3.4571(20) MHz. The centrifugal distortion constants are used to derive the intramolecular force field and a normal coordinate analysis is performed. The Cl nuclear quadrupole coupling tensor indicates that the field gradients in ClCN are slightly perturbed upon complex formation but not enough to proscribe their use in structural determinations of weakly bound complexes.

Amine−Hydrogen Halide Complexes: Experimental Electric Dipole Moments and a Theoretical Decomposition of Dipole Moments and Binding Energies

“…is the semirigid rotor rotational Hamiltonian, including centrifugal distortion, H quad accounts for nuclear quadrupole coupling, and H Stark = − μ · E (where E is the electric field strength and μ is the molecular electric dipole moment). The Hamiltonian matrix is constructed in the | I , J , F , M F 〉 basis using matrix elements reported previously. − The dipole moment of each complex was obtained from a least-squares fit of the observed Stark-shifted frequencies with the rotational and ( 79 Br) nuclear quadrupole coupling constants constrained to their previously determined zero-field values. Examination of the observed Stark shifts indicated that for 15 NH 3 −H 79 Br, the Stark effects were essentially second order, whereas for (CH 3 ) 3 15 N−H 79 Br, H 3 15 N−H 35 Cl and (CH 3 ) 3 15 N−H 35 Cl, significant deviations were observed for some components, requiring the full diagonalization performed by QSTARK .…”

Structural and Electronic Properties of the Charge-Transfer Complex H3P⋅⋅⋅Br2 Determined by Fourier Transform Microwave Spectroscopy

“…[21] Values of D J , B 0 , B H 3 P and B Br 2 are given in Tables 3 and 4, while m has been defined in connection with Equation (6). The resulting values for k s of the six isotopomers of H 3 P´´´Br 2 are identical within experimental error and are listed in Table 5 [a] Ref.…”

Study of the Rotational Spectrum of the Ne–N2O van der Waals Dimer with a Fourier Transform Microwave Spectrometer

“…Rotational and centrifugal distortion constants were fitted to the center frequencies rot , using Watson's Sreduction, I r -representation Hamiltonian (28). The resulting spectroscopic constants, including three rotational constants, four quartic centrifugal distortion constants (i.e., D J , D JK , d 1 , and d 2 ), and two sextic distortion constants (i.e., H J and H JK ), as well as the nuclear quadrupole coupling constants aa (1), bb (1), aa (2), and bb (2) are given in Table 2 for both 20 Ne-14 N 14 NO and 22 Ne-14 N 14 NO. The numbers 1 and 2 in the parentheses indicate the terminal and central 14 N nuclei, respectively.…”