Rotation-tunneling spectrum of the deuterated ammonia dimer

Karyakin, E. N.; Fraser, Gerald T.; Loeser, J. G.; Saykally, Richard J.

doi:10.1063/1.478920

Cited by 16 publications

(8 citation statements)

References 20 publications

(32 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The potential surface of ammonia dimer is configurationally complex. In addition to possessing a rather flat intermolecular surface, inversion at nitrogen plays a role in the spectroscopy that is used to determine the experimental structure . The classic microwave study by Nelson, Fraser, and Klemperer, wherein ammonia dimer is found to have an asymmetric structure, is inconsistent with ab initio reports from the 1980s.…”

Section: Discussionmentioning

confidence: 99%

Ab Initio Calculation of Nonbonded Interactions: Are We There Yet?

2000

View full text Add to dashboard Cite

We present calculations for the nonbonded interactions in the dimeric complexes: methane dimer, ammonia dimer, water dimer, H2O·(NH3), CH4·(NH3), and (FHF)- as a function of theory level (HF, DFT(B3LYP), MP2, LMP2, MP3, MP4, CCSD(T), and others) and basis set (6-31G**, cc-pVXZ, X = D, T, Q, 5). Dimer minimum energy structures are determined at the MP2 theory level for the cc-pVTZ basis set employing analytical second derivatives. For HF and DFT levels of theory, methane dimer and one structure of CH4·(NH3) are not bound. The basis set superposition error (BSSE) begins to converge (becomes systematically small) for basis sets larger than cc-pVTZ. For hydrogen-bonded systems, most levels of theory seem to give reasonable estimates of the experimentally known binding energies, but here, too, the BSSE overwhelms the reliability of the binding energies for the smaller basis sets. The CH4·(NH3) dimer has two minimum energy conformations with similar binding energies, but very different BSSE values especially for small basis sets (cc-pVXZ, X ≤ T). On the basis of these calculations, we present a discussion of ab initio calculations of nonbonded interactions for molecules, such as phenethylamine, that have different conformations. Suggestions for possible next steps in the calculation of nonbonded interactions are presented.

show abstract

Section: Discussionmentioning

confidence: 99%

Ab Initio Calculation of Nonbonded Interactions: Are We There Yet?

2000

View full text Add to dashboard Cite

show abstract

“…However, further studies showed the need for further refinement. Karyakin et al 16 determined the A + A states interchange splitting of (ND 3 ) 2 . Their observed value of 264 GHz is about 25% smaller than the calculated 331 GHz, while the calculated A + A interchange splitting of (NH 3 ) 2 of 475 GHz matches the experimental value of 483 GHz very well.…”

Section: Analysis and Discussionmentioning

confidence: 99%

“…Heineking et al 14 analyzed the 14 N nuclear hyperfine structure of some rotation-inversion transitions in the lowest K ) 1 E 3 state. Behrens et al 15 studied the infrared molecular beam depletion spectrum of the ammonia dimer in cold helium clusters, in which they found that the dominating interchange tunnelings in free ammonia dimers are largely quenched in a superfluid helium cluster at 0.4 K. Finally, Karyakin et al 16 measured the millimeter and submillimeter-wave molecular beam spectrum of the A + A state of (ND 3 ) 2 . Mu ¨ller-Dethlefs and Hobza 17 used the ammonia dimer as an illustrative example in their review article on noncovalent interactions.…”

Section: Introductionmentioning

confidence: 99%

Terahertz Vibration−Rotation-Tunneling Spectroscopy of the Ammonia Dimer: Characterization of an out of Plane Vibration

et al. 2006

View full text Add to dashboard Cite

Terahertz vibration-rotation-tunneling transitions have been measured between ca. 78.5 and 91.9 cm -1 , and assigned to A-E (ortho-para) combinations of NH 3 monomer states. The spectrum is complicated by inversion splittings that correlate to E symmetry monomer rovibronic states. Twenty progressions have been assigned to six excited states involving an out-of-plane vibration and an in-plane intermolecular vibration. The quality of the fit was affected by strong Coriolis interactions among these states and possibly an additional K ) 2 state that was not explicitly observed in the data.

show abstract

“…24,35 The electric field dependent rotational energy level shifts are related to the permanent electric dipole moments (EDMs) of InA via the Stark Hamiltonian, which was added as a perturbation to the asymmetric rigid rotor Hamiltonian in the analysis of the Stark spectra. 24,45 A simulation of the Stark spectrum recorded at an applied electric field of 423 V cm À1 was fit by least squares using 48…”

Section: Fluorescence Excitation Spectramentioning

confidence: 99%

“…This (NH 3 ) 2 arrangement is similar in structure to that found in the (NH 3 ) 2 dimer, as measured in great detail using far-infrared and microwave spectroscopy. [46][47][48] Examples of the optimized structures of InA and InA 2 are shown in Fig. 4.…”

Section: Theoretical Structures and Vibrational Frequenciesmentioning

confidence: 99%

Experimentally measured permanent dipoles induced by hydrogen bonding. The Stark spectrum of indole–NH3

Fleisher

Young

Pratt

2012

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Hydrogen bond pairs involving the chromophore indole have been extensively studied in the gas phase. Here, we report high resolution electronic spectroscopy experiments on the indole-NH(3) hydrogen bond pair in the absence and presence of an electric field. The S(1)-S(0) origin band of this complex recorded in zero field at high resolution reveals two overlapping spectra; a consequence of NH(3) hindered internal rotation. The barrier to internal rotation is predicted by theory to be less than 20 cm(-1) in the ground state, therefore requiring a non-rigid rotor Hamiltonian to interpret the spectra. Conducting the experiment in the presence of an applied electric field further perturbs the already congested spectrum of the complex, but makes possible the measurement of the permanent electric dipole moments in its S(0) and S(1) states. These values reveal significant changes in electron distribution that arise from hydrogen bonding effects.

show abstract

Rotation-tunneling spectrum of the deuterated ammonia dimer

Abstract: Articles you may be interested inThe rotational spectrum and dynamical structure of LiOH and LiOD: A combined laboratory and ab initio study

Cited by 16 publications

References 20 publications

Ab Initio Calculation of Nonbonded Interactions: Are We There Yet?

Ab Initio Calculation of Nonbonded Interactions: Are We There Yet?

Terahertz Vibration−Rotation-Tunneling Spectroscopy of the Ammonia Dimer: Characterization of an out of Plane Vibration

Experimentally measured permanent dipoles induced by hydrogen bonding. The Stark spectrum of indole–NH3

Contact Info

Product

Resources

About