Tripod-shaped molecules

The sequence of tripod-shaped TPA(OH) complexes down each channel is also polar, and the concept of a polar template may be appropriate. Furthermore, the concept of polar diffusion should be explored at low temperature, polar molecules should adopt a specific orientation during diffusion down a polar channel. 

Stearic acid is a saturated fatty acid. This means it has only single bonds between its carbon atoms. This means it can coil up and form into random shapes. Double bonds between carbon atoms restrict the bending of the molecule at the point of the bond, like a hinge that lets a door swing back and forth but not up and down. Triple bonds are even more restrictive, locking the joint in place three-dimensionally, like the legs of a tripod. 

Linear systems with an NO3 donor set are exemplified by simple saturated molecules, which show preferences toward lighter, higher charged metal ions, such as linear (90). Branched systems include tripodal ligands having different central atoms and 0-donors terminating the chains, for example, (91) and (92). Their coordination chemistry is partly directed by their shape, which tends to support trigonal... 

The terms Y -shaped [109], tripodal , 1,1-double-tailed or peg-shaped [110] describe the molecular geometry of this type of amphiphile. At the hydrophilic head two hydrophobic tails are joined close together or even by a common link to the headgroup. Very famous examples for this molecular architecture are the biologically active phospholipids and sphingolipids [111]. Lipids occur in all biological cells and have common solubility properties generally they are water-insoluble, amphiphilic molecules... 

Various tripod systems have been synthesized with the goal of fullerene complexation (Fignre 9). One such scaffold involves a tripod with rigid linkers this system is proposed to make a supramolecnlar network wherein the net stoichiometry is expected to be 1 2 (tripod to fullerene). On the basis of an experimental analysis, it was conclnded that each fnllerene is always held by two porphyrins. These two porphyrins can be oriented snch that a U-shaped arrangement is defined between two porphyrins contained within the same molecule, 8. Or, the two porphyrins can from two separate tripods. In aU cases, the distances between the snrface of Ceo and the porphyrin plane were fonnd to range from 2.52 to 2.92 A, as wonld be expected for a system in which n-n interactions persist. 

Highly symmetrical cube-shaped polyamine caging ligand 19 has been prepared in [25] by imine condensation of tripodal amine tren with formaldehyde by Scheme 2.8 its Td-symmetric hexahedral cage framework encapsulates two water molecules. 

---