Quasi-planar geometries

The technologies for making nm-scale structures by current lithographic methods are largely restricted to planar or quasi-planar geometries. (An array of trenches carved into... 

Of the two explanations advanced, one is the usual ir-bonding concept involving d orbitals of the third-row elements (34), whereas the other refers to a more electrostatic picture (60). The lone pair of electrons at the carbanion is supposed (a) to interact with the suitable empty orbitals of silicon and (b) to suffer much less repulsive interactions from bond pairs in the presence of the larger elements. Both arguments call for the planar or quasi-planar geometry of the carbanion, which is observed in phosphorus ylides. 

Fig. 1.77. The optimized atomic structures of model catalysts comprising Aus (a and b), Au4 (c), and AusSr (d) clusters adsorbed at an F center of an MgO(lOO) surface. For Aus, two relevant isomers are depicted, separated by an energy difference of 0.29eV with the quasi-planar geometry being the ground state. The optimal geometries for the adsorption of the O2 molecule on these model catalysts are shown in panels e-h...

In thiosalen-type complexes the Ni11 ion usually has a four-coordinate square planar geometry.1360,1361 Complex [Ni(510)] shows a quasi-reversible reduction at —1.36 V and an irreversible... 

Lagomarsino, M.C., Dogterom, M., Dijkstra, M. Isotropic nematic transition of long, thin, hard spherocylinders confined in a quasi-two-dimensional planar geometry. J. Phys. Chem. 119, 719-721 (2003)... 

Molecular Orbital Calculations.— The ground state of the anion radical of thioformaldehyde ( S,) is calculated, on the basis of the PNO-CEPA ab initio method, to be bound, near to its quasi-planar equilibrium geometry [reaction (3)]. 

The hybrid compound (56), obtained in good yield by reaction of the monocondensed dicyanomethylene with BTC, exhibits two quasi-reversible reduction waves to the radical anion and dianion E i2 = -0.07 V E i2 = -0.31 V V5. SCE) due, probably, to the more planar geometry of this compound [126]. 

---