OMS, OM(η²-SO), and OM(η²-SO)(η²-O₂S) Molecules (M = Ce, Th) with Chiral Structure: Matrix Infrared Spectra and Theoretical Calculations

Abstract

Infrared absorptions of the matrix isolated OMS, OM(η-SO), and OM(η-SO)(η-OS) (M = Ce, Th) molecules were observed following reactions of laser-ablated Ce and Th metal atoms with SO during condensation in excess argon and neon. Band assignments for the main vibrational modes were confirmed by appropriate SO and SO isotopic shifts. B3LYP, BPW91 density functional, and CASSCF/CASPT2 calculations were performed to characterize these new reaction products and to explore the admixture of f orbitals into the bonding giving stronger M≡O triple bonds. It is very interesting that both OM(η-SO) and OM(η-SO)(η-OS) molecules show chiral structure.

M←NCCH3, M-η2-(NC)–CH3, and CN–M–CH3 Prepared by Reactions of Ce, Sm, Eu, and Lu Atoms with Acetonitrile: Matrix Infrared Spectra and Theoretical Calculations

“…In the past few decades, studies on the bonding characteristics of lanthanide and actinides have attracted much attention. − Early research believed that for lanthanides, the main orbitals that participate in bonding are the 5d and 6s, 4f valence orbitals are often considered chemically inert because of their relatively low energy and contraction in radial distribution. , However, this view does not apply to early lanthanide elements, such as Ce, the 4f orbitals of which usually show some contributions to bonding. , Lanthanide ions display a strong affinity to electron donors such as O and N, − so it is important to explore the properties of bonding between lanthanide metals and N.…”

“…26,27 However, this view does not apply to early lanthanide elements, such as Ce, the 4f orbitals of which usually show some contributions to bonding. 28,29 Lanthanide ions display a strong affinity to electron donors such as O and N, 30−32 so it is important to explore the properties of bonding between lanthanide metals and N.…”

Bidentate Sulfur Dioxide Complexes of Scandium, Yttrium, and Lanthanum Difluorides

“…A recent gas-phase mass spectrometric study revealed the formation of a series of lanthanide–SO 2 complex anions upon collision-induced dissociation (CID) of Ln­(CH 3 SO 2 ) 4 – , and both oxygens of SO 2 were found to bind the lanthanum and lutetium centers on the basis of density functional theory (DFT) calculations . A similar coordination mode was found in the SO 2 complexes of titanium, zirconium, hafnium, cerium, and thorium. , However, it is still unclear whether such a coordination mode is preserved in the neutral SO 2 complexes of scandium, yttrium, and lanthanum because of the limited number of known examples.…”

“…23 A similar coordination mode was found in the SO 2 complexes of titanium, zirconium, hafnium, cerium, and thorium. 24,25 However, it is still unclear whether such a coordination mode is preserved in the neutral SO 2 complexes of scandium, yttrium, and lanthanum because of the limited number of known examples.…”

Side-On Sulfur Monoxide Complexes of Tantalum, Niobium, and Vanadium Oxyfluorides

“…Similar to O 2 , sulfur monoxide possesses a 3 Σ – ground state, with the frontier orbitals resembling those of CO in energy and size, and the two additional valence electrons occupying the 3π* antibonding orbital. − The coordination modes of diatomic SO toward mononuclear metal center can be mainly divided into end-on (η 1 -SO/OS) and side-on (η 2 -SO) fashion . End-on bonded complexes as well as multinuclear compounds bridged by SO have been reported and characterized by NMR spectroscopy, X-ray crystallography, and theoretical calculations. ,− However, structural information regarding the complexes containing side-on bonded SO ligand is scarce, and only the complexes in the form of OM­(η 2 -SO) have been identified for some transition metals. − …”