Functionalization strategies

In order to improve the performance of COFs, introduction of functional groups has been proven to be a good choice.The properties of functionalized COFs can be significantly enhanced, especially for high performance gas storage. So, we will show various approaches to introduce functionalities into COFs in the following sections. 

To improve the storage capacity of hydrogen, methane, and carbon dioxide in COFs, the strategy of doping an electropositive metal into the 

In addition, Lan et al. studied the effects of the various metal dopants on CO2 capture using multiscale simulations. As a result. Mg, Be, and Ca failed to bind with COFs, while Li, Ti, and Sc can. However, Sc and Ti bind with COFs so strongly that structural deformation of the materials incurs. Hence, Lan et al. believed that Li shows the best potential for modification of COFs for CO2 capture. 

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Mini-encyclopedia of papermaking wet-end chemistry. Additives and ingredients, their composition,functions, strategies for use http //www4.ncsu.edu 8030/ hubbe/ONP.htm... 

One of the most convenient of these tether-directed functionalization strategies exploits the macrocyclization of C60 with bismalonate derivatives in a double Bingel reaction.156,571 With the exception of the cis-1 bisaddition product, all possible bisaddition patterns have been obtained by this macrocyclization reaction (Figure 13). As a general... 

PoUino JM, Week M. Non-covalent side-chain polymers design principles, functionalization strategies and perspectives. Chem Soc Rev 2005 34 193-207. 

Side chain functionalization of covalently functionalized pol5mers can take place either by prepolymerization functionalization, which is the functionality that has been bestowed to the monomer, or by postpolymerization functionalization, which is after the polymerization, when the polymer backbone is subsequently functionalized with the desired moiety (Pollino and Week 2005). Although both approaches have been employed successfully in covalent pol5mer chemistry, the first approach can be synthetically more demanding but always yields 100% functionalization, which is not the case for most postpolymerization functionalization strategies. 

Figure 5.6 Functionalization strategies of random copolymer 3 based on a combination of hydrogen bonding and coulombic interactions.

Figure 5.7 Functionalization strategies of copol3Tner 4 based on multiple hydrogen bonding interactions.

Terpolymer Functionalization Strategies Combing Hydrogen Bonding, Metal Coordination, and Pseudorotaxane Formation... 

Figure 5.21 Orthogonal noncovalent cross-linking as well as functionalization strategy of terpolymer using hydrogen bonding and metal coordination interactions.

In most of the cases the interaction of micron-sized particles is not mediated by a linker sequence [135]. Usually the particles are directly covered with complementary sequences that bypass the need of having a third component in solution. This approach is illustrated in Fig. 30 where a few key aspects of the functionalization strategy chosen in [136, 137] are stressed. 

Further products containing the 1,2,4-trioxolane ring, which prove to be stable under a variety of reaction conditions, can be accessed by the same remote functionalization strategy (Scheme 39) <1994TL1743, 1994TL1743, 1998T8525>. 

In principle, the functionalization strategies can be subdivided into methods allowing (1) direct incorporation of the functionality during spinning and (2) postfunctionalization of the fibers after mesh production. 

Noncovalent functional strategies to modify the outer surface of CNTs in order to preserve the sp2 network of carbon nanotubes are attractive and represent an effective alternative for sidewall functionalization. Some molecules, including small gas molecules [195], anthracene derivatives [196-198] and polymer molecules [118, 199], have been found liable to absorb to or wrap around CNTs. Nanotubes can be transferred to the aqueous phase through noncovalent functionalization of surface-active molecules such as SDS or benzylalkonium chloride for purification [200-202]. With the surfactant Triton X-100 [203], the surfaces of the CNTs were changed from hydrophobic to hydrophilic, thus allowing the hydrophilic surface of the conjugate to interact with the hydrophilic surface of biliverdin reductase to create a water-soluble complex of the immobilized enzyme [203]. 

Fig. 1.20 Functionalization strategy for a polynorbornene (PNBE) coating of SWCNTs. Path A adsorption of organic precursors (a)...

Fig. 14.28 Functionalization strategies for tetracene, leading to a variety of potential Jt-stacked arrangements.

To evaluate the participation of hydrogen bonding in DNA replication selectivity mechanisms Kool described a seminal functional strategy based on chemically modified DNA polymerase substrates [3a,d,g], He developed nucleotide analogs in which the polar natural DNA nucleobases are replaced by non-polar aromatic molecules, which closely mimic the shape and size of the natural nucleobases but have at least significantly diminished ability to form stable hydrogen bonds (Figure 4.1.4). 

An ingenious route to the solubilization of pentacene involves addition of substituent groups that can be removed thermally after film formation is complete. The reactive nature of the central aromatic ring in pentacene makes it a good diene for Diels-Alder type reactions, and the reversibility of this reaction makes this approach ideal for such a functionalization strategy. 

A recent iterative approach to pentacene (Scheme 3.3) has yielded the hexacene-quinone derivative 17 (plus several related compounds) [29]. The novel aspect of such compounds lies in the dipole induced by having electron-withdrawing substituents on only one end of the pentacene, and the unique self-assembly opportunities enabled by this functionalization strategy. 

Functionalization of pentacene with the specific aim of improving performance in devices is a recent endeavor - the first use of a functionalized pentacene in a field-effect transistor was reported only recently (2003) [26], Functionalization of pentacene has led to the ability to engineer the solid-state arrangement, electronic, and solubility properties of this important semiconductor and to improve its stability and film-forming ability. Recent functionalized pentacene materials have yielded devices with properties comparable with those of the parent acene, have enabled the formation of devices from solution-deposited films, and have even changed the semiconductor behavior of this organic molecule from p-type to n-type. As functionalization strategies are refined, materials with all of the properties necessary for commercial device applications should soon be developed. 

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