Tetrahedral molecular geometry

About: Tetrahedral molecular geometry is a research topic. Over the lifetime, 1795 publications have been published within this topic receiving 30706 citations.

Distorted cage structures of Sin (n = 20, 24, 26, 28, 30, 32) clusters

Abstract: We have performed calculations on the fullerene cage structures and the binding energies of Sin (n = 20, 24, 26, 28, 30, 32) clusters by the full-potential linear-muffin-tin-orbital molecular dynamics (FP-LMTO-MD) method. It is found that the fullerene cages are not stable, and relax into structures which are severely distorted. Except for Si20, their atomic arrangement tends towards tetrahedral geometry. After the structural distortion, about two silicon atoms can still be filled into the inside spaces of the distorted cages for Sin (n = 26-32).

Synthesis, characterization and nonlinear optical effects of M4(µ4-O) core complexes with large two-photon absorption cross-section

Abstract: Four tetranuclear 2-mercaptobenzothiazole cluster compounds [M4O(MBT)6] (M = Fe, Co, Ni, Cu; MBT = 2-mercaptobenzhothiazole) were synthesized and characterized by elemental analyses, IR and UV–vis spectra, and single crystal X-ray crystallography. The crystal structures of [M4O(MBT)6] (M = Fe, Co, Ni) confirm that the four metal(II) atoms locate four capsheaves of a tetrahedral skeletal structure and a tetracoordinate O2− as an interstitial atom occupies the centre position of this tetrahedron. The metal atoms all possess slightly distorted tetrahedral geometry. The thermal gravimetry data indicate that these clusters all have good thermal stability. The nonlinear absorption of four cluster solutions (in DMF) were measured by open-aperture Z-scan technique at a 532 nm wavelength. The results of Z-scan experiments show that these clusters all have remarkable and very strong nonlinear optical absorption effects. The largest two-photon absorption cross-section is 172880 GM for cluster [Fe4O(MBT)6].

Aluminepin: Aluminum Analogues of Borepin and Gallepin

Abstract: We report synthesis of dibenzoaluminepin as the first aluminepin, an aluminum analogue of borepin and gallepin. This compound contains one molecule of ethereal solvent on the Al atom, which adopts a tetrahedral geometry. The central 7-membered aluminepin ring has a boatlike conformation and was characterized by single-crystal X-ray diffraction, (1)H/(13)C NMR, and DFT studies. In addition, NICS, NBO, and theoretical calculations provide insight into the nature of the bonding and aromaticity of aluminepins.

Monolayer solids of tetrahedral molecules

Abstract: Monolayer solids of CH4, CD4, and CF4 adsorbed on the basal plane surface of graphite are modeled with atom–atom interaction models and quasiharmonic lattice dynamics. Single molecule adsorption, the stability of registry lattices at monolayer condensation, and the stability of triangular tripod‐down lattices relative to a denser monolayer packing are treated. The Novaco–McTague perturbation theory of the modulation of an incommensurate monolayer by the substrate is extended to molecular adsorbates with orientational degrees of freedom. Experimental data for monolayers of tetrahedral molecules on graphite are summarized; the model calculations give a fair account of the data, with some discrepancies in the energies of monolayer condensation.