Magneto-infrared spectra of the Si2, Ge2, and Sn2 molecules in rare-gas matrices

Abstract

Absorption spectra of Si2, Ge2, and Sn2, observed between 50 and 5000 cm−1 in neon and argon matrices at 4 K, were assigned to the lowest 3Πu←X 3Σg− electronic transition. In all three cases, the Franck–Condon envelope of vibrational bands allowed T00, ωe′, ωe′xe′ to be determined. In the Si2 molecule [near Case (a)] T00=313 cm−1 and each vibrational band was split into Ω triplets (0,1,2) in the upper state. A Zeeman effect on these lines was detected in magnetic fields up to 4 T. As the spin–orbit coupling becomes larger in Ge2 and Sn2, the 1u←X0+g transition [case (c)] was observed, and the corresponding parameters in the upper state determined. For Sn2 the magnetic-dipole 1g←X0+g transition was also detected and identified by the splitting and broadening of the band in magnetic fields up to 4 T. The results are discussed in the context of the ab initio calculations and other experimental results on these molecules.

Study on structures and electronic properties of neutral and charged MgSin- (n= 2–10) clusters with a Gaussian-3 theory

“…The most stable structures for Si n clusters verified by theoretical methods [1][2][3][4][5][6][7] and experimental schemes [8][9][10][11][12][13][14][15], such as anion photoelectron spectroscopy [8][9][10][11][12] or Raman [13] and infrared measurements [14,15], are line for Si 2 , isosceles triangle for Si 3 , rhombus geometry for Si 4 , trigonal bipyramid for Si 5 , tetragonal bipyramid for Si 6 , pentagonal bipyramid for Si 7 . Although the predicted lowest-energy ground states for larger cluster were found to be dependent on the type of the calculation and also on the optimization technique [16].…”

“…Silicon clusters have been studied both experimentally and theoretically because of their intrinsic interest from the point of view of chemical structure and bonding as well as for their importance in the microelectronics industry [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The most stable structures for Si n clusters verified by theoretical methods [1][2][3][4][5][6][7] and experimental schemes [8][9][10][11][12][13][14][15], such as anion photoelectron spectroscopy [8][9][10][11][12] or Raman [13] and infrared measurements [14,15], are line for Si 2 , isosceles triangle for Si 3 , rhombus geometry for Si 4 , trigonal bipyramid for Si 5 , tetragonal bipyramid for Si 6 , pentagonal bipyramid for Si 7 .…”

Configuration Interaction Study of the Low-Lying Electronic States of GaBi

“…7 Neumark and co-workers [8][9][10][11][12] have used the negative ion zero-electron kinetic photodetachment spectroscopic techniques to study the electronic states of the neutral group IV and group III-V clusters. Weltner and co-workers [13][14][15] have studied matrix-isolated electron-spinresonance (ESR) spectra of small clusters of Ga, Si, Sn, and mixed group III-V elements. By using laser vaporization techniques, the infrared absorption spectra of GaX and InX (X) P, As, Sb) molecules in rare-gas matrices have been observed by Li et al 15,16 Although a large number of studies have been reported for the electronic structure and spectroscopic properties of GaAs, there seems to have a very little data on the isovalent GaBi molecule.…”

Theoretical studies on singlet and triplet states of Ge2

“…[5] 0.11 *** 308 Exp. [1] 0.09 *** 308 Theoretical studies on singlet and triplet states of Ge 2 3259 Figure 7. Improved potential curves for selected states of Ge 2 .…”

“…In a matrix absorption experiment, Li et al [1] observed the ground state (GS) of Ge 2 to be X 3 AE À g , with the 1 3 Å u state lying only 694 cm À1 (0.086 eV) higher. The GS of isovalent Si 2 is also X 3 AE À g , and 3 Å u lies 0.08 eV higher [2], but C 2 has an X 1 AE þ g (1p u 4 ) GS, with 3 Å u 0.09 eV, and 3 AE À g 0.80 eV higher [3].…”