Guest free space

Fig. 9.5 Lattice thermal conductivity K at 150 K (top) and 300 K (bottom) versus guest free space Figure adapted from [30] and completed with data from [15, 31-34]. The K data at 300 K are, except for CsgZn4Sn42, all for single crystalline samples...

Figures 9.5 and 9.6 show that indeed both structural and electronic properties influence the lattice thermal conductivity of intermetaUic clathrates. In Fig. 9.5, /C/ is plotted for different type-I clathrates versus the guest free space, an analysis done for many type-I clathrates by Suekuni et al. [29,30]. For calculating the guest free space...

K. Suekuni, S. Yamamoto, M.A. Avila, T. Takabatake, Relation between guest free space, U. lattice thermal conductivity reduction by anharmonic rattling in type 1 clathrates. J. Phys. Soc. Jpn. 77SA, 61 (2008)... 

Dendrimers appear to have interiors that are, to all intents and purposes, empty and they, therefore, are able to accommodate guest molecules and also nanoparficles. Early theoretical work suggested that dendrimers develop in concentric shells, and enclose a considerable amount of empty space. More recent theoretical studies have suggested that they may not be as much free space as first thought, and this has been confirmed by X-ray diffraction studies. NMR has shown that there is a reasonable free volume within dendrimers though there is some experimental evidence that the amount of free volume varies with the thermodynamic quality of the solvent. This, in turn. 

Zinc hydroxide and alkoxide species are particularly relevant to catalytic processes, often forming the active species. The cooperative effects of more than one zinc ion and bridged hydroxides are exploited in some enzymatic systems. Zinc alkyl phosphate and carboxylate materials have been important in the formation of framework compounds, often containing large amounts of free space for the inclusion of guest molecules. Aldehyde and ketone compounds are of low stability due to the poor donor capabilities of the ligands however, a number of examples have recently been characterized. 

The guest-free apohosts are unsaturated not only with respect to the space but also in some cases to the functional moieties involved. In the Ag -networked host 15-AgOTf (cf. Fig. 3) having a huge aromatic ligand, the metal centres are co-ordinatively saturated. The host shows affinity to aromatic guests, which may allow host-guest tt-tt interactions [71]. 

In a further study of the compression behavior of Siisg sample we used Raman spectroscopy in the DAC [66]. The guest-free elemental polymorph with space group Fd3m and 34 atoms in the corresponding primitive unit cell gives rise to zone center vibrational modes ... 

Schemes 4.9 and 4.10. The encapsulated aromatic guest forms stacking interactions with facial azine fragments of 488, while that with bulky adaman-tyl substiment occupies the remaining free space within its cavity the photomediated 1,4-radical reaction of the caged molecules is described in Sect. 5.2. The coordination capsule 483 also gave the corresponding homoguest 1 1 and 1 2 cage complexes shown in Scheme 4.10 [11].

The switching efficiency of lumophore-spacer-receptor systems can be improved by using multiple receptor modules. The PET rate is increased in the device when free of guest ions since more than one site can provide the transiting electron. The simplest cases, such as 4, are those where the receptor units are well separated to prevent interdependent ion binding with an interposed lumophore to minimize the lumophore-receptor spacing for maximum PET rates. Besides this statistical effect, receptors may also cooperatively participate in PET. This may be the case in 5 and 6. ... 

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