Rebek's Diacid-Pyrazine Complex
This is the crystal structure of a hydrogen-bonded complex of the
so-called "Rebek's diacid" (a molecular host with convergent carboxyl
groups) with the small diamine pyrazine. The structures of this and
related complexes had been controversial. Rebek originally proposed
that two hydrogen bonds are formed in the complex; later calculations by
Jorgensen suggested that
only one could be made. The X-ray structures of the
complexes support the original formulation of Rebek. For a brief
communication describing the first X-ray structure of one of these
complexes, see
"Molecular Structure of Rebek's
Diacid-Quinoxaline: Confirmation of Two-Point Binding." R.
A. Pascal, Jr., and D. M. Ho, J. Am. Chem. Soc.
1993, 115,
8507-8508.
