Single occupancy

If the t2 orbitals are occupied unevenly, Jahn-Teller distortions occur. For configuration d4, one of the t2 orbitals is unoccupied for d9, one has single occupation and the rest double. As a consequence, the ligands experience differing repulsions, and a flattened tetrahedron results (Fig. 9.2). Typical bond angles are, for example in the CuCl4 ion, 2x 116° and 4 x 106°. 

For a ds ion such as Fe3+, the five electrons may be unpaired in the set of five d orbitals, or they may be present as two orbitals occupied by pairs of electrons and one orbital having single occupancy. A complex such as [Fe(H20)s]3+ is typical of the first bonding mode (five unpaired electrons, high spin, outer orbital), whereas [Fe(CN)6]3 is typical of the second (one unpaired electron, low spin, inner orbital). Three orbitals can accommodate six electrons, so a d6 ion such as Co3+ should form two... 

Note that single occupancy is assigned to AO s which are principally utilized in forming the sigma bonds in linear OX2 -... 

Mobility is related to invariants such as the following people move for 1 h per day -the average speed, since it was measured for the first time in 1923, remains stable in the range 35-40 km h - people tend to relate mobility to mental freedom and according to the U S Bureau of Transportation as many as 90% of kilometers covered are run in vehicles with a single occupant. 

As expected the Group VB amide V(NMe2)4 possesses a paramagnetic ground state. On the basis of single occupancy of the i>, metal orbital the molecular ground state is expected to be 2fl, a deduction that has been confirmed by ESR studies of this compound (42, 184). Tentative assignments for the various predicted ionic states are indicated in Table XXXV. 

The single-occupancy constraints mentioned on page 90 of ref. 14 are an example of such lateral restriction). ... 

Fe has six 3d electrons in the only unfilled subshell. The maximum unpairing occurs with double occupancy of one of the available d subshells and single occupancy of the remaining four. There will be 4 unpaired electrons. 

Divalent manganese occurring as high-spin cations in all minerals and possessing the unique electronic configuration (t2g) eg)2 with single occupancy of all... 

Aryl cations are highly reactive intermediates with two possible electronic configurations, the singlet and triplet states. The former is a localized cation with a vacant a orbital at the dicoordinated carbon atom, whereas the latter has a diradical character with single occupancy of the g orbital and the charge being delocalized in the... 

The size of H- also implies that H nuclei cannot be close to each other as, for example, in adjacent octahedral or tetrahedral sites in VH0 75. This is also a valid comment, but it accounts correctly for the single occupancy of faces in such unit cells by hydrogen, thus eliminating the assumption made earlier that hydrogen tended to surround itself by vacant sites. 

In our lattice model, each lattice site occupies a single lattice cell of volume v. In view of the cooperative nature of the hole motion, the barrier energy is treated by a mean field average [28], and is related to the Gibbs free energy per molecule (Ag) in a system restrained to single occupancy of cells by... 

In the following the reduced quantities = NJN (i = 0, 1, 2, s) and q = Nc/N are considered. Add some physics to the problem with the additional rules as follows. Placing one ball in a box requires energy Eu and placing two balls requires E2- Furthermore, our balls are particles with spin s = so in the case of single occupancy (polaron), there is a twofold degeneracy. One obtains... 

When anionic micelles are employed the counter ions can often have a profound effect upon the photophysical processes of micellised compounds. Thus if the counter ion is a heavy atom, e.g. silver, intersystem crossing can become highly efficient and make it possible for phosphorescence to be readily detected at room temperature (Kalyanasundaram et al., 1977 Humphry-Baker et al., 1978). If, on the other hand, the counter ion does not interfere with photophysical processes, high triplet yields can be observed, e.g. for N-methyl-phenothiazine (Moroi et al., 1979a), zinc(II) tetrasulphophthalo-cyanine (Darwent, 1980), because the high likelihood of single occupancy of micelles precludes triplet-triplet annihilation. 

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