Bis-calixarenes

Bis(butadiene) complexes, with tantalum, 5, 173 Bis(z-butanethiolato) complexes, with bis-Cp Ti(IV), 4, 601 Bis(calixarene) complexes, as organic molecule hosts, 12, 799 Bis(carbene) complexes with gold(I), 2, 287-288 with manganese, 5, 780, 5, 826 with mercury, 2, 429 with palladium, 8, 230 with silver , 2, 206... 

Numerous examples of 1,3-alternate conformers of calix[4]arenes are known, but relatively few have been established by X-ray crystallography. In addition to earlier examples, more recent ones include the tetra-O-substituted 92a and 92b as a K complex) (see Figure 4.9), the doubly-bridged 92c,the bis-calixarene 93, and the calix[4]arene 40 containing four extraannular OH groups. 

The bis-calixarene 272, referred to as an ionophoric tube , contains binding... 

Capsule-shaped Ir(l) and Rh(l) cationic complexes with a triphosphinocaltx[6]arene as a multidentate ligand were recently synthesized (Figure 33). These organometallic bis-caltxarene complexes showed dynamic behavior with size-selective molecular encapsulation, which was confirmed by variable-temperature P H NMR measurements in the presence of various molecules. X-ray crystal analysis showed that the calix[6]arene moiety adopted the same pinched-cone conformation as the non-coordinated caltxarene. Molecules such as CFlj,Cly or CICH2CH2CI are too small to fit the cavity of the iridium and rhodium bis-calixarene complexes and cannot restrict the dynamic behavior at 25 °C. On the contrary, molecules such as X2CHCHX2 (X = C1 or Br), benzene, toluene, o- or w-xylene just fit in the cavity and show the dynamic behavior. Finally, large molecules (p-xylene, cumene, mesitylene, etc.) could not enter the cavity. 

Reversible encapsulation of snitable guests by the fluorine-containing bis-calixarene capsule... 

Assembly of the negatively charged calix[4]arene 162 and its analogs 163 and 164 (Scheme 3.46) with 165 and the caging properties of supramolecular bis-calixarene capsules 377-379 have been studied in [47] using ESI-MS, H NMR, and ITC meth-... 

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