Hybridization covalent

The general understanding of the electronic structure and the bonding properties of transition-metal silicides is in terms of low-lying Si(3.s) and metal-d silicon-p hybridization. There are two dominant contributions to the bonding in transition-metal compounds, the decrease of the d band width and the covalent hybridization of atomic states. The former is caused by the increase in the distance between the transition-metal atoms due to the insertion of the silicon atoms, which decreases the d band broadening contribution to the stability of the lattice. 

Through X-ray scattering studies of the electron densities in MgCu2, Kubota et al. (2000) found concentrations of electrons between the Cu atom pairs, but not between Mg—Cu pairs. They interpreted this as p3d3 covalent hybrid Cu—Cu bonds embedded in Mg metal. 

In the actinide series, therefore, the energies of the 5f 6d, Is, and Ip orbitals are about comparable over a range of atomic numbers (especially U to Am), and since the orbitals also overlap spatially, bonding can involve any or all of them. In the chemistries this situation is indicated by the fact that the actinides are much more prone to complex formation than are the lanthanides, where the bonding is more ionic. The difference from lanthanide chemistry is usually attributed to the contribution of covalent hybrid bonding involving 5/ electrons. 

There Is an additional element which appears In the case of the T1 superconductors which may be worthy of note and further speculation. We first recall that some years ago, Allender, Bray, and Bardeen (32) (ABB) proposed a specific excltonlc mechanism of superconductivity employing a model of semiconductor-metal Interfaces. In the ABB model, the metallic electrons at the Fermi energy tunnel Into the semiconductor and Cooper pair by exchanging virtual "excltons", l.e., virtual electron-hole pairs. As discussed above, the pDOS structure of Tl/2212 and Tl/2223 shows that both systems can be viewed as a metal-semiconductor (or metal-semlmetal) superlattice structure, where the CUO2 metal layers provide conduction electrons and the Tl-03-02 layers serve as low-gap semiconductors. Since the T1 s (d 2 nd 02, 03 P2 states are covalently hybridized, a virtual elicitation from the non-bonding Px,y states of 02 and 03 to the anti-bonding T1 s (d Pz state may... 

H.S. Jeong, Y.K. Ko, Y.H. Kim, D.K. Yoon, H.-T. Jung, Self assembled plate-like structures of single-walled carbon nanotubes by non-covalent hybridization with smectic hquid crystals. Carbon 48, 774-780 (2010)... 

Cannizzo, C., Mayer, C., Secheresse, R, et al. (2005). Covalent Hybrid Materials Based on Nanolatex Particles and Dawson Polyoxometalates, Adv. Mater., 17, pp. 2888-2892. 

Section 3.4.S.4 (Tables 116 205) chemical shifts cs of DNA sequences and of RNA-DNA hybrids (the RNA-DNA covalent hybrids are collected in the DNA tables for computer-technical reasons). 

Immobilization of small proteins in MWNTs with 3.0-5.0nm in inner tube diameters was first observed with HRTEM in 1995 as mentioned in Sect. 2.4 [164,165]. CNTs were non-covalently hybridized with fuUerenes to provide fullerene peapods in 1998 [49,224], This novel nanomaterial attracted considerable attention because of the great possibility for tuning the electronic structures of CNTs and shielding the encapsulated molecules by the carbon cage [222],... 

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