Gj. Kemperman et al., Cavities, layers, and channels in the hosting framework of molecular complexes derived from cephradine, EUR J ORG C, (19), 2001, pp. 3641-3650
The cephalosporin-type antibiotics Cephradine, Cephalexin, and Cefaclor for
m clathrate-type complexes with a variety of naphthalene derivatives. The c
rystal structures of these complexes are isomorphous. Interestingly, the ho
sting framework formed by these cephalosporins can adapt to the guest molec
ule. This phenomenon of induced-fit appears to have a much larger potential
, with the consequence that a series of smaller compounds (such as benzene
derivatives) as well as bulkier compounds can also be hosted by Cephradine.
When benzene derivatives were used as guests, pronounced deviations in the
antibiotic framework were observed, and it is possible to induce deviation
s strikingly different from those found for the complexes with the naphthal
ene derivatives. Evidently, the hosting structure formed by Cephradine is h
ighly flexible. Hosting frameworks containing layers, channels, and various
other types of cavities can be obtained by selection of an appropriate gue
st molecule. Remarkably, a number of structural features and interactions r
emain unaffected in all these antibiotic frameworks. These persistent featu
res seem to delineate the boundaries of framework formation for these antib
iotics, thus defining the scope of complex formation.