Electronic structure and bonding

The theory proposed by Dewar et al. (154) is also based on a tr-bonded P—N skeleton of sp2-hybridized nitrogen and sp3-hybridized phosphorus but postulates a pair of linear combinations of phosphorus dxz and dy orbitals for overlap with an adjacent nitrogen p2 orbital. The result is a system of almost independent three-center 7t-bonds containing two phosphorus atoms and one nitrogen atom (Fig. 18). More detailed calculations appear to support this theoretical treatment (167,168,171, 172, 318) and indicate that conjugation beyond the three-center islands is of minor importance in cyclotriphosphazene derivatives (167). X-Ray crystallographic data for heterogeneously substituted cyclophosphazene derivatives (Section V,C) and evidence 

Recently, trans-annular phosphorus-phosphorus bonding has been postulated to account for the stability of the cyclotriphosphazene system (40-42, 169). In eight-membered phosphazene rings, it is believed that trans-annular bonding occurs for phosphorus atoms separated by two bonds, and trans-annular antibonding for phosphorus atoms four bonds apart (408). 

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Only two complex fluorides of pentavalent plutonium are known, both having been prepared by Penneman et al. ( 1). One of these, Rb2PuF7, appeared to be stable its crystal structure ( 1) and its electronic spectrum (2) have been reported. The other, CsPuF6, appeared to decompose after a few days (J ) and only its crystal structure was reported. Our interest in the bonding and electronic structure of Pu(V) and particularly in Pu(V) fluorides prompted the present study of CsPuFg. 

Copper, iron, and aluminum are three common metals in modem society. Copper wires carry the electricity that powers most appliances, including the lamp by which you may be reading. The chair in which you are sitting may have an iron frame, and you may be sipping a soft drink from an aluminum can. The properties that allow metals to be used for such a wide range of products can be traced to the principles of bonding and electronic structure. 

Electron energy loss spectroscopy An analytical technique used to characterize the chemistry, bonding, and electronic structure of thin samples of materials. It is normally performed in a transmission electron microscope. The inelastically scattered electron beams are spectroscopically analyzed to give the energy spectrum of electrons after the interaction. 

Bonding and Electronic Structure of Phosphides, Arsenides, and Antimonides by X-Ray Photoelectron and Absorption Spectroscopies... 

Use the periodic table and other information concerning bonding and electronic structure to explain the following observations. 

Robert Mulliken United States chemical bonds and electronic structure of molecules... 

Bonding and electronic structure Electron spectroscopies", electron density by X-ray diffraction and spin density by neutron diffraction... 

In this section, we survey the various theories of bonding and electronic structure which will be invoked elsewhere in the book and which will be regularly encountered by any serious student of inorganic chemistry. As pointed out in Section 1.2, it must be stressed that no one theory is wholly adequate, and the inorganic chemist must have at least a passing knowledge of several. The all-purpose theory would probably... 

Rotational fine structure may also be resolved in the electronic spectra (see also Section 2.6) of molecules in the gas phase. This can provide structural information about unstable, short-lived species which cannot be isolated as pure substances. It may also yield structural parameters for molecules in electronic excited states. Such information is relevant to discussion of bonding and electronic structure. 

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