How an Inert‐Gas Matrix Can Modify the Molecular Properties of Lanthanide Trifluoride

Abstract

Ab initio computations performed on LaF(3) x Ar(n) (n = 1-21) complexes allow a quantification of the short-range many-body interactions arising in the argon matrix. It is shown that the molecular properties of LaF(3) are strongly influenced by the embedding medium. The largest investigated cluster, LaF(3) x Ar(21), resembles an hcp structure with the LaF(3) molecule occupying the central substitutional site (see figure).

Dissociative Addition of Water to a Main Group 13 Metal Cluster: Computational Study of the Reaction of Gallium Dimer with H2O

“…For the isolated H 2 O, the ν 1 (a 1 ), ν 2 (a 1 ), and ν 3 (b 2 ) anharmonic frequencies estimated at the latter computational level, ,, at 3737, 3641, and 1592 cm –1 , compare best with the measured fundamentals at 3756, 3657, and 1595 cm –1 , respectively. The calculated IR data for the Ga 2 ···OH 2 ( 3 B 1 ) complex show that, upon the complexation, the ν 2 (a 1 ), the bending vibration of water is shifted to the red, by 11–13 cm –1 based on both the harmonic and anharmonic calculations, consistent with experiment. , It should be also remembered that the matrix host–guest interactions perturb the molecular properties and therefore can affect the observed vibrational frequencies, especially for H 2 O. − …”

“…Employing instead the vibrational self-consistent field (VSCF) method of Gerber et al , provides an anharmonic frequency of 974 cm –1 for this key mode of the isomer 2 (at B3LYP/AE, Table S2, Supporting Information) that compares adequately with the observed wavenumber. As mentioned above, the matrix host–guest interactions are likely responsible for differences between the computed gas phase data and those observed in the matrix. − …”

Extending the Row of Lanthanide Tetrafluorides: A Combined Matrix‐Isolation and Quantum‐Chemical Study

“…The lanthanide trifluorides have been the subject of numerouse xperimental and theoretical investigations owing to their special electronic structure and the question as to whether their structures have C 3v or D 3h symmetry. [1][2][3][4][5][6][7][8][9][10][11][12] There is substantial interest in the formationof novel oxidation states of the lanthanides, notably through the work of Evans and co-workersw ho have found complexeso fL ni n the + II formalo xidation state in contrast to the usual + III oxidationstate. [13,14,15] The availablew ork on the + II oxidation state has recently been summarized by Meyer; [16] we note that only af ew difluorides are known.…”

“…The chemistry of the lanthanides is mostly dominated by compounds in the oxidation state +III owing to the relative inertness of the 4f electrons caused by the contracted radial distribution and the relatively low energy (stability) of these orbitals. The lanthanide trifluorides have been the subject of numerous experimental and theoretical investigations owing to their special electronic structure and the question as to whether their structures have C 3 v or D 3 h symmetry . There is substantial interest in the formation of novel oxidation states of the lanthanides, notably through the work of Evans and co‐workers who have found complexes of Ln in the +II formal oxidation state in contrast to the usual +III oxidation state .…”

A theoretical study on the LaF3 molecule embedded in argon matrix

“…In spite of its simplicity, it has been seen that important experimental spectroscopic features are well reproduced at least at qualitative level 15. In a recent communication, we further clarified the significant effects of inert‐gas matrix on spectroscopic properties considering much more elaborated models 16.…”