Slate, electronic

D. Woolard, W. Zhang, and B. Gelmont, A Novel Interband-Resonant-Tunneling-Diode (I-RTD) Based High-Frequency Oscillator, Solid Slate Electronics 49, 257-266 (2005). 

Briliouin zones Electronic theory of metals divides the electronic slates of a metal into a series of broad energy levels known as Briliouin zones. 

Jahn-TeHer effect The Jahn-Teller theorem states that, when any degenerate electronic slate contains a number of electrons such that the degenerate orbitals are not completely filled, the geometry of the species will change so as to produce non-degenerate orbitals. Particularly applied to transition metal compounds where the state is Cu(II)... 

Orgel diagrams Simple graphs showing the relation between the energies of various electronic slates and the crystal field splitting. 

I h e n otation h ere rn ean s th at electron 1 occupies a spatial orbital tpi with spin up (no bar on top ] electron 2 occupies spatial orbital tPi with spin down (a baron top), and so on. An RIIF description of the doublet S=l/2 slate obiamed by adding an electron to would be... 

Another reaction unique to conjugated dienes is the Diels-Alder cycloaddition. Conjugated dienes react with electron-poor aikenes (dienophiles) in a single step through a cyclic transition slate to yield a cyclohexene product. The reaction is stereospecific, meaning that only a single product stereoisomer is formed, and can occur only if the diene is able to adopt an s-cis conformation. 

Fora [4 + 2 -7r-electron cycloaddition (Diels-Aldei reaction), let s arbitrarily select the diene LUMO and the alkene HOMO. The symmetries of the two ground-slate orbitals are such that bonding of the terminal lobes can occur with suprafacial geometry (Figure 30.9), so the Diels-Alder reaction takes place readily under thermal conditions. Note that, as with electrocyclic reactions, we need be concerned only with the terminal lobes. For purposes of prediction, interactions among the interior lobes need not be considered. 

In contrast with the thermal process, photochemical [2 + 2] cycloadditions me observed. Irradiation of an alkene with UV light excites an electron from i /, the ground-slate HOMO, to which becomes the excited-slate HOMO. Interaction between the excited-state HOMO of one alkene and the LUMO of the second alkene allows a photochemical [2 + 2j cycloaddition reaction to occur by a suprafacial pathway (Figure 30.10b). 

The stereochemistry of any pericyclic reaction can be predicted by counting the total number of electron pairs (bonds) involved in bond reorganization and then applying the mnemonic "The Electrons Circle Around. " That is, thermal (ground-slate) reactions involving an even number of electron pairs occur with either conrotatory or antarafacial stereochemistry. Exactly the opposite rules apply to photochemical (excited-state) reactions. 

Pericyclic reaction (Chapter 30 introduction) A reaction that occurs by a concerted reorganization of bonding electrons in a cyclic transition slate. 

Figure 3-4. Tlic order parameter A, Or) for the solilon solution (thick line) and the electron density IV/o(Jl) 2 for the intragap stale accompanying the solilon (dotted line) are shown to the left. To the right the spectrum of single-electron slates for the solilon lattice configuration is depicted.

Gas Phase to Solid Slate Evolution of the Electronic aiul Optical Properties... 

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