Structural and Quantum Chemical Study of Bi₅³⁺ and Isoelectronic Main-Group Metal Clusters. The Crystal Structure of Pentabismuth(3+) Tetrachlorogallate(III) Refined from X-ray Powder Diffraction Data and Synthetic Attempts on Its Antimony Analogue

Abstract

Pentabismuth(3+) tetrachlorogallate(III), (Bi(5)(3+))(GaCl(4)(-))(3), has been synthesized by reducing a BiCl(3)-GaCl(3) melt with bismuth metal and the crystal structure refined from X-ray (Cu Kalpha(1)) powder diffraction data. The structure was found to belong to space group R-3c, with the lattice parameters a = 11.871(2) Å and c = 30.101(3) Å (Z = 6). It is isostructural with the previously characterized Bi(5)(AlCl(4))(3). An attempt to synthesise the antimony analogue Sb(5)(GaCl(4))(3) by reducing a SbCl(3)-GaCl(3) mixture with gallium metal produced a black solid phase. The gallium content of this phase is consistent with the stoichiometry Sb(5)(GaCl(4))(3), and the Raman spectrum of the phase dissolved in SbCl(3)-GaCl(3) comprises strong, low-frequency bands attributable to Sb-Sb stretch vibrations in Sb(5)(3+) or another reduced antimony species. Quantum chemical analyses have been performed for the isoelectronic, trigonal pyramidal closo-clusters Sn(5)(2-), Sb(5)(3+), Tl(5)(7-), Pb(5)(2-), and Bi(5)(3+), both with extended Hückel (eH) and Hartree-Fock (HF) methods. The HF calculations were performed with and without corrections for the local electron-electron correlation using second-order Møller-Plesset perturbation theory (MP2). All theoretical results are compared and evaluted with respect to experimental cluster structures and vibrational frequencies. The results from the calculations agree well with available experimental data for the solid-state structures and vibrational spectra of these cluster ions, except for the Tl(5)(7-) ion. Isolated Tl(5)(7-) is suggested to be electronically unstable because of the high charge density. The Sb(5)(3+) cluster ion is indicated to be stable. According to the calculations, Sn(5)(2-) and Pb(5)(2-) may be described in terms of edge-localized bonds without substantial electron density between the equatorial atoms, whereas Sb(5)(3+) and Bi(5)(3+) have electron density evenly distributed over all M-M vectors. Furthermore, the theoretical results give no support for a D(3h) --> C(4v) fluxionality of these clusters.

The [Sn5]2-Cluster Compound [K-(2,2,2-crypt)]2Sn5- Synthesis, Crystal Structure, Raman Spectrum, and Hierarchical Relationship to CaIn2

“…The agreement between the calculated and measured intensities is also quite satisfactory, except for the pairs mª 4 (E') and mª 2 (A' 1 ), exhibiting intensities which are in reverse order to the measured ones. The calculated frequencies correspond also with those recently reported [9].…”

“…Note that the assigned sequence of the wave numbers for [Sn 5 ] 2± derived from the quantum chemical calculations in this work is consistent with the theoretical assignment of Ulvenlund et al [9], but quite different from that reported for the isoelectronic clusters [Ge 5 ] 2± [12] and [Bi 5 ] 3+ [13], namely: mª 1 (A' 1 ) > mª 2( A' 1 ) > mª 6 (E') > mª 4 (E@).…”

Electronic Excitations in Homopolyatomic Bismuth Cations: Spectroscopic Measurements in Molten Salts and an ab initio CI-Singles Study

“…More recently, the full single-crystal analysis of [Bi 5 (AlCl 4 ) 3 ] that included the intramolecular structure of the Bi 5 3 ion was reported. [14] The Bi 5 3 ion was studied with extended Hückel theory [16] and Ulvenlund et al [17] reported RHF, MP2, and CISD results of ab initio calculations of the D 3h -Bi 5 3 structure. We have reported the results of liquid-state neutron-diffraction measurement of D 3h Bi 5 3 together with highly correlated ab initio computations that employed effective core potentials and well-polarized basis sets.…”

Molekülstruktur und theoretische Untersuchungen von (PPh4)2[Bi10Cu10(SPh)24]

“…[1] Neben 14 ], [3] [Bi 38 O 44 (Hsal) 26 (Me 2 CO) 16 22 ]. [6] Hingegen ist über die Verbrückung 4+ (E = S, Se, [10] Te [11] ) erhalten werden.…”

“…Die Summe der S-Cu-S-Bindungswinkel be- (1) ). [21] Eine [26] ). Die Bindungsverhältnisse in diesen Polykationen können mit den Wade-Regeln erklärt werden.…”