Aggregation modes

Scheme 1 Graphical representation of various aggregation modes in alkali metal compounds.

Figure 30 Synthesis of carbene analog 434 and influence of the coordinating solvent on its aggregation mode.

A key property of these polymetallic complexes is geometrical structure, more variable and diverse than the coordination stereochemistries of monometallic complexes or the symmetrical lattices of non-molecular compounds. The following well-defined aggregation modes illustrate the geometrical scope of the field. 

For one thing, those saved from heart attacks will ordinarily remain under medical treatment, at high cost, for the rest of their lives treatment in the aftermath of heart attacks is expensive and life-long. For another, many of those who have suffered heart attacks will not return to the work force, brought down by chronic heart disease. For still another, by an aggregate mode of accounting... the true cost of saving the life of someone from a heart attack must also calculate the costs of whatever other illnesses they [sic] incur over the remainder of their lifetime, which would not have happened if they had died from the attack... 

The role of the absolute configuration at C3 is determinant not only for aggregation/gelation but also for the aggregation modes of monolayers developed at the air-water interface [98],... 

It should be noted, however, that for molecular species of geometries other than spheres, different approximations are needed to describe the hydrodynamic frictional coefficient, / [8]. Since there is a relationship between rg and the effective molecular size and shape of the molecular species, it is clear that diffusion coefficients are sensitive to the structural properties and aggregation modes of these species. Therefore, the diffusion coefficient can be used to probe binding phenomena and intermolecular interactions [10, 11]. 

Fig. 6.13. Schematic representation of some of the different molecular interactions and aggregation modes identified by diffusion NMR in these giant capsules [32-33],...

Elaissari A, Pefferkorn E. Polyelectrolyte induced aggregation of latex particles influence of the structural relaxation of adsorbed macromolecules on the colloid aggregation mode. J Colloid Interface Sci 1991 141 522-533. 

Finally, visual insight into the aggregation mode and morphology in 46 was obtained by scanning electron microscopy (SEM) of dry samples, or xerogels. While the precursors show only negligible fiber formation, a 3D network was obvious for 46. 

Scheme 1.10. Proposed aggregation modes of PI in water with different THF content [58]. Reproduced by permission of The Royal Society of Chemistry...

The diverse chemical and photophysical prop>erties of porphyrins are in many cases due to their different aggregation mode and, as a result of interchromophoric interactions, perturbations in the electronic absorption spectra of dyes occur. Deviations from Beer s law are often used to investigate the porphyrin aggregation in solution. 

Murata, K. Aoki,M. Suzuki, T. Harada, T. Kawabata. H. Komori, T. Ohseto. F. Ueda, K. Shinkai. S. Thermal and light control of the sol-gel phase-transition in cholesterol-based organic gels—Novel helical aggregation modes as detected by circular-dichroism and electron-microscopic observation. J. Am. Chem. Soc. 1994, 116, 6664-6676. 

Krupitsky, H. Stein. Z. Goldberg, I. Crytalline complexes, coordination polymers and aggregation modes of tetra(4-pyridyl)porphyrin. J. Inch Phenom. 1994. 18, 177-192. 

The Eqs. (26) and (28) were used for synthesis process description within the frameworks of fractal analysis and irreversible aggregation modes [132]. Let us pay attention to the fact, that the fractal dimertsion Devalue determines to a considerable extent Q value, but molecular weight is independent on this parameter. 

Fig. 10 Possible aggregation mode in the micelle. Reproduced with permission from ref. 64. Copyright 2014, John Wiley and Sons.

Figure 34.15 Water-soluble oligophenylene derivatives developed by Lee and co-workers, displaying a diversity of aggregation modes in water.

Obtaining geometrically well-defined J-aggregate-type assemblies involving only weak interactions is still a very challenging area of supramolecular chemistry. The example reproduced in Figure 32 illustrates the aggregation mode... 

Scheme 1 a Aggregation mode of interlayer micelle-occluded nanocrystals, b Graphic presentation of the formation mechanism of CaCOs mesorings. Gray, calcium carbonate red, hydrophobic block blue, soluble neutral block yellow, charged block. The red arrow indicates the decreasing gradient of occluded polymer within the disklike structure. (Reproduced from [156], 2006, American Chemical Society)... 

Fig. 5.2 Schematic representation of aggregation modes (redrawn after Sangeetha and Maitra 2005)...

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