Rigid platforms

In addition to the tripodal structural motifs mentioned above, one obvious choice to imbue a ligand with threefold symmetry is to use 1,3,5-trisubstituted benzene as a base. The formation of the alternating conformation for substituents on a hexasubstituted benzene is a well-known phenomenon an early example where this was used in a supramolecular context was by Harshom and Steel in 1996 [4], Subsequently the principle has been used widely particularly in the detection of anions [5-8]. The parent 1,3,5-tris(bromomethyl)-2,4,6-triethylbenzene is fairly complex to prepare [9], however, the corresponding mesitylene 

Glacial acetic acid [CORROSIVE] Hydrogen bromide in acetic acid (31%) [CORROSVE] 

Round-bottomed flask (100 mL) Heating mantle/stirrer and stirrer bar Reflux condenser Glassware for filtration 

Note This reaction should be carried out in a fume hood. 

Round-bottomed flask (250 mL) Pressure-equalized dropping funnel Inert atmosphere line Glassware for work-up 

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Tension leg platforms (TLP) are used mainly in deep water where rigid platforms would be both vulnerable to bending stresses and very expensive to construct. A TLP is rather like a semi-submersible rig tethered to the sea bed by jointed legs kept in tension. Tension is maintained by pulling the floating platform down into the sea below its normal displacement level. The legs are secured to a template or anchor points installed on the seabed. 

The pendulum impact test employs a pendulum type of hammer. It is carried out in four ways Izod, Charpy, Chip and Tensile. The apparatus used for the pendulum test consists of a heavy base with a vice for clamping the specimen and a pendulum hammer swinging at a sample. The machine base must be kept on a rigid platform to prevent vibrational energy losses. 

The sketch represents half of the structure, i.e., one pair of columns with rigid platform and rigid column bases there is a point of inflection at mid-height of each column. 

When exeessive vibration is deteeted in the gear box of a eompressor train (Figure 21-14) and is transferred to the platform below, a dampening effeet ean be ereated by inereasing the rigidity of the support below. This effeet ean be aeeomplished by first filling the platform eavity and then the gear-box support with epoxy mortar. 

Thus, it has been shown that calix[4]aryl esters exhibit remarkably high selectivity toward Na [11-14]. This is attributable to the inner size of the ionophoric cavity composed of four 0CH2C=0 groups, which is comparable to the ion size of Na, and to the cone conformation that is firmly constructed on the rigid ca-lix[4]arene platform (Scheme 2). 

An understanding of the relationships between sequence, structure, and function of /l-solenoid proteins also opens the way for successful de novo molecular design of such molecules, with applications in nanotechnology or biomaterial studies. For example, these structures may allow the assembly of rigid and regular nanoscale lattices and display platforms (Hyman et aL, 2002) that are also durable in their resistance to high temperature, proteases, and other extreme conditions. 

Porphyrins are very attractive as a platform for the design of sensors for molecule recognition. The flat and relatively rigid structure of porphyrins offers the possibility of constructing various types of recognition sites. Numerous functionalized... 

This confidence stems from a unique capability to co-evolve with the fluid IT environment within which Infosys operates. Continuity and change are inherent in Infosys s operations as it uses the very resources and capabilities it has built in the past as platforms to explore and exploit emerging opportunities. Scalability lies in Infosys s ability to encapsulate its past experiences such that the accumulated stock and associated flows result not in core rigidities - the perpetuation of Infosys as it once was - but in dynamic capabilities that fuel its continual transformation. That is, Infosys represents a continually upgradable platform, a firm that is always in the making. 

A by-product of the solvophobic collapse of the mPE backbone is the formation of a hydrophobic cavity. Similar cavities have been explored for use as hosts in molecular recognition however, these cavities are typically quite rigid and synthetically difficult to access [4, 6]. The formation of a hydrophobic cavity through supramolecular folding of the mPE backbone offers a modular platform for the study of small molecule binding with supramolecular hosts. 

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