Rational Design and X-ray Molecular Structure of the First Irido-Cryptand and Encapsulation of a Tetrafluoroborate Anion The CNRS and UPMC are gratefully acknowledged for supporting this work. We thank Prof. D. Davoust and Dr. E. Condamine (IRCOF-Université de Rouen, France) for carrying out the special 13C{19F} NMR experiments on a 600 MHz Bruker instrument equipped with a TXO probe 13C/19F,1H.

Iridium and rhodium coordination chemistry has been used to self-assemble metallocryptands: Treatment of two equivalents of [Cp*M(solv)3][BF4]2 (Cp*=C5(CH3)5; M=Rh, Ir; solv=acetone) with three equivalents of the bidentate ligand 1,3-bis(aminomethyl)-2,5-dimethoxy-4,6-dimethylbenzene (L) afforded the first irido- and rhodio-cryptands [(Cp*M)2L3][BF4]4 in high yields (70–85 %). The use of less congested ligands increased the accessibility of the cavity of the metallocryptands and enabled the encapsulation of tetrafluoroborate ions (see scheme).