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Af bond in Af

Theoretical studies of the hydrogen bond generally agree that the Af bond will be linear in the absence of peculiarities of packing in the solid.

Moreover, it will be asymmetric until a certain critical Af distance is reached, below which it will become symmetric.

There is ample evidence from many sources that the Af bond in Af is symmetric.

The Af distance in Af is 2.26 Aj.

There is evidence, though less convincing than for Af, that the Af bond in nickel dimethylglyoxime is symmetric.

Here the Af distance is 2.44 Aj.

A number of semiempirical estimates by various workers lead to the conclusion that the Af bond becomes symmetric when the Af bond length is about 2.4 to 2.5 A, but aside from the possible example of nickel dimethylglyoxime there have been no convincing reports of symmetric Af bonds.

Douglass has studied the crystal structure of Af by x-ray diffraction.

He finds the structure contains an Af bond with the Af distance of Af.

There is, then, the possibility that this Af bond is symmetric, although Douglass was unable to determine its symmetry from his x-ray data.