Chiral metal–organic
materials (CMOMs), can offer molecular
binding sites that mimic the enantioselectivity exhibited by biomolecules
and are amenable to systematic fine-tuning of structure and properties.
Herein, we report that the reaction of Ni(NO3)2,S-indoline-2-carboxylic acid (S-IDECH), and 4,4′-bipyridine (bipy) afforded a homochiral
cationic diamondoid,dia, network, [Ni(S-IDEC)(bipy)(H2O)][NO3],CMOM-5. Composed of rod building blocks (RBBs) cross-linked by bipy linkers,
the activated form ofCMOM-5adapted its pore structure
to bind four guest molecules, 1-phenyl-1-butanol (1P1B), 4-phenyl-2-butanol
(4P2B), 1-(4-methoxyphenyl)ethanol (MPE), and methyl mandelate (MM),
making it an example of a chiral crystalline sponge (CCS). Chiral
resolution experiments revealed enantiomeric excess,ee, values of 36.2–93.5%. The structural adaptability ofCMOM-5enabled eight enantiomer@CMOM-5crystal
structures to be determined. The five ordered crystal structures revealed
that host–guest hydrogen-bonding interactions are behind the
observed enantioselectivity, three of which represent the first crystal
structures determined of the ambient liquidsR-4P2B,
S-4P2B, andR-MPE.