Molecule able to contain another molecule within itself
In
chemistry, a cavitand is a container-shaped
molecule.[2] The cavity of the cavitand allows it to engage in
host–guest chemistry with guest molecules of a complementary shape and size. The original definition proposed by
Cram includes many classes of molecules:
cyclodextrins,
calixarenes,
pillararenes and
cucurbiturils.[3] However, modern usage in the field of
supramolecular chemistry specifically refers to cavitands formed on a
resorcinarene scaffold by bridging adjacent phenolic units.[4] The simplest bridging unit is methylene (−CH2−), although dimethylene (−(CH2)2−), trimethylene (−(CH2)3−),
benzal,
xylyl,
pyridyl,
2,3-disubstituted-quinoxaline,
o-dinitrobenzyl,
dialkylsilylene, and
phosphonates are known. Cavitands that have an extended aromatic bridging unit, or an extended cavity containing 3 rows of aromatic rings are referred to as deep-cavity cavitands and have broad applications in host-guest chemistry.[5][6] These types of cavitands were extensively investigated by
Rebek, and
Gibb, among others.
Applications of Cavitands
Specific cavitands form the basis of rigid templates onto which de novo proteins can be chemically linked. This template assembled synthetic protein (TASP) structure provides a platform for the study of
protein structure.[7]