One electron bond

A large number of polymeric substances, (RAs) or (ArAs), are also known (113). They are usually prepared by the reduction of arsonic acids with hypophosphorous acid (100,114) or sodium dithionite (115). Most of these polymers have not been well characterized. An insoluble, purple material, poly(methylarsinidene) [26403-94-1], (CH As), prepared by the interaction of methylarsine and a dihalomethylarsine, however, has been shown by an x-ray investigation to have a ladderlike polymeric stmcture in which the inter-mng distances correspond to one-electron bonds (116) ... 

However, a very unexpected situation is found24 for the phenyl allyl sulphone (53), for which a one-electron cleavage occurs in aprotic non-aqueous solvents. The allyl radical is apparently not electroactive at the cleavage potential, and forms the dimer. Therefore, in this one-electron bond scission no strong base is formed and the isomerization into the vinylic isomer is not observed (Figure 9). Similarly, the cleavage of phenyl propargyl... 

The lavish use made of one-electron bonds by some English authors is without justification. 

It is shown that a stable shared-electron bond involving one eigenfunction for each of two atoms can be formed under certain circumstances with either one, two, or three electrons. An electron-pair bond can be formed by two arbitrary atoms. A one-electron bond and a three-electron bond, however, can be formed only when a certain criterion involving the nature of the atoms concerned is satisfied. Of these bonds the electron-pair bond is the most stable, with a dissociation energy of 2-4 v. e. The one-electron bond and the three-electron bond have a dissociation energy... 

In Sections 42 and 43 we shall describe the accurate and reliable wave-mechanical treatments which have been given the hydrogen molecule-ion and hydrogen molecule. These treatments are necessarily rather complicated. In order to throw further light on the interactions involved in the formation of these molecules, we shall preface the accurate treatments by a discussion of various less exact treatments. The helium molecule-ion, He , will be treated in Section 44, followed in Section 45 by a general discussion of the properties of the one-electron bond, the electron-pair bond, and the three-electron bond. 

In order to obtain information as to the extent to which the bond strength S of an orbital can be considered a qualitative measure of its bondforming power and also as to the quantitative relation between the energy of a bond and the strengths of the bond orbitals involved in its formation, we have now carried out the thorough discussion of various sp and spd one-electron bonds between identical atoms. 

Fig. 1.— Energy curves for one-electron bonds involving 2s-2p hybridization.

An atomic bond orbital p = a ps + bpP can be varied from a pure 5 orbital to a pure p orbital by varying the ratio of the coefficients a and b. Energy curves calculated for one-electron bonds between similar orbitals on two atoms, as functions of p = rAB/2an, with rAB the internuclear... 

Fig. 4.—Calculated one-electron bond energy-values (D/k, full curves) and squared bond strength values (S, dashed curves) for s-p hybridization.

The results of the calculation of one-electron bond energies for orbitals of the type wpis +... 

Fig. 6b.—Contour diagram of D/k (calculated one-electron bond energy divided by a constant) for s-p-d hybridization.

Theoretical energy curves for one-electron bonds between two atoms are calculated for bond orbitals formed by hybridization of 2s and 2p orbitals, 35 and 3 orbitals, and 35, 3p, and 3d orbitals, the same radial part being used for the orbitals in a set. It is found that for s-p hybridization the bond energy is closely proportional to S3, with 5 the magnitude of the angular part of the bond orbital in the bond direction. This relation is less satisfactorily approximated in the case of s-p-d hybridization. 

The energy of the one-electron bond in the lithium molecule ion is calculated with consideration of the s-p separation to be 1.19 e. v and the hybrid bond orbital involved is shown to involve about equal contributions from the 25 and 2p orbitals of the lithium atom. 

Radical IV can be considered as a unique phosphorus radical species. Reduction of the parent macrocycle with sodium naphtalenide in THF at room temperature gave a purple solution. The FPR spectrum displayed a signal in a 1 2 1 pattern, with flp(2P)=0.38 mT. DFT calculations on radical IV models indicated a P-P distance of 2.763 A (P - P is3.256 A in the crystal structure of the parent compound and the average value of a single P-P bond is 2.2 A). According to the authors, the small coupling constant arises from the facts that the principal values of the hyperfine tensor are of opposite sign and that the a P P one electron bond results from overlap of two 3p orbitals [88]. 

Nicker reactivities are relatively flat with cluster size(lc). For clusters smaller than the decamer a weak even odd pattern exists down to the trimer, the smallest cluster reported to react. This pattern might be suggestive of a one-electron bonding scheme as used in very early calculations on Ni n clusters(30). 

Organometallic radicals are important intermediates in biological and catalytic reactions. The structure and formation mechanism of radicals trapped in y-irradiated molecular sieves exposed to methanol and ethylene have been studied by EPR spectroscopy. It was found that Ag CH2OH+ radical with one-electron bond between Ag and C is formed by the attack of -CH2OH hydroxymethyl radical on Ag+ cation. 

Already in the thorium dimer, Th2, we see another pattern. The 7s population is reduced to close to one. The electron is moved to 6d, and a strong quadruple bond is formed, involving three two-electron bonds and two 6d one-electron bonds. We also start to see some population of the 5f orbitals that hybridizes with 6d. 

The strongest bond is formed between the Pa atoms in Pa2. Here the contribution of 6d is maximum, and we see a complete promotion to the atomic state with five unpaired electrons. A quintuple bond is formed with a short bond distance and a bond energy close to 5 eV. The bond contains the (7sag)2(6dnu)4 triple bond plus a 6dag two-electron bond and two 6dhg one-electron bonds. The 5/population is increased to one electron, but we still do not see any molecular orbital dominated by this atomic orbital. They are all used but rather in combination with the 6d orbitals. 

Linus Pauling, "The Nature of the Chemical Bond. Applications of Results Obtained from the Quantum Mechanics and from a Theory of Paramagnetic Susceptibility to the Structure of Molecules," JACS 53 (1931) 13671400 also, "The Nature of the Chemical Bond. II. The One-Electron Bond and Three-Electron Bond,"... 

The Nature of the Chemical Bond. II. The One-Electron Bond and Three-Electron Bond." JACS 53 (1931) 32253237. 

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