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Electronic spectra for the hypermetallic oxide MgOMg have been observed in the 21 100 cm−1–24 000 cm−1 spectral range using laser induced fluorescence and two-photon resonantly enhanced ionization techniques. Rotationally resolved data confirmed the prediction of a X ̃ 1 Σ g + ground state. The spectrum was highly congested due to the optical activity of a low-frequency bending mode and the presence of three isotopologues with significant natural abundances. Ab initio calculations predict a bent equilibrium structure for the à 1B2 upper state, consistent with the observation of a long progression of the bending vibration mode. However, the vibrational intervals were not reproduced by the theoretical calculations. In part, this discrepancy is attributed to strong vibronic coupling between multiple electronically excited states. Two-photon ionization measurements were used to determine an ionization energy of 6.5800(25) eV. [ABSTRACT FROM AUTHOR]

The Fourier transform microwave spectra of the various isotopologs of the weakly bound complex of carbon dioxide with the most abundant molecule in the atmosphere, nitrogen, have been measured. The structure of the complex has been determined and evidence for the inversion of the N2 is presented. The molecule is T-shaped, with the OCO forming the cross of the T, a structure consistent with that deduced from a previous rotationally resolved infrared experiment. A significant wide-amplitude bending motion of the N2 is deduced from the values of the (nearly identical) nuclear quadrupole coupling constants of the nitrogen nuclei. The spectroscopic results are compared with high-quality ab initio calculations. We examine the consequences of the N2 CO2 complex formation in the atmosphere upon the greenhouse warming potential of carbon dioxide. [ABSTRACT FROM AUTHOR]

The rotational spectra of cyclohexeneoxide and its van der Waalscomplex with argon have been observed with a Balle-Flygare type pulsedjet Fourier transform microwave spectrometer in the 6 to 20 GHz region.This work improves the existing rotational and quartic centrifugaldistortion constants of cyclohexene oxide, its six singly substituted 13C, and the 18O isotopologue. In addition, the 17O isotopologue was observed in natural abundance. The quadrupolecoupling constants for the 17O isotopologue are χaa= 8.855(5), χbb= −4.560(4), andχcc= −4.296(4) MHz. The argon–12C6H1016O complex has rotationalconstants of A= 2146.4825(2), B= 908.64292(8), and C= 859.00320(8) MHz. Additionally,the six unique singly substituted 13C isotopologues ofthe argon complex are reported here. The position of the argon thatis consistent with the parent and six 13C complex rotationalconstants is above the ring on the side opposite the epoxide. [ABSTRACT FROM AUTHOR]

This work details a gas phase study of the bonding of hydrogen to the metal in a simple diatomic analogue of a metal organic framework (MOI3), copper fluoride, via dihydrogen complexation. This is the first microwave study of these types of interactions./ = 1--0 transitions of para- H2--CuF, ortho-D2--CuF, and HD--CuF have been measured and analyzed. The complexes were prepared by laser ablating a metal copper rod in the presence of a gas mix of 0.6% SF6 and 3% H2 in Ar undergoing supersonic expansion. The binding energy of this complex is addressed through quantum chemical calculations and measured nuclear quadrupole coupling constants for copper and deuterium. The significant change in the calculated binding energy and nuclear quadrupole coupling constants in relation to similar molecules suggest bonding greater than that typical of van der Waals interactions. [ABSTRACT FROM AUTHOR]