Extended ligands

Base-pairing interactions have been realized in metal complexes by extending ligand functionalization to include two complementary nucleobases (136). Sequential alkylation of 1,2-dithioethane using 2-chloroethyl-9-adenine and 3-chloropropyl-l-thymine yields the AT-... 

A four-component self-assembling system was described by Kuroda (46). Two rhodium porphyrins are coordinated by the terminal pyridine groups of an extended ligand constructed from a tartrate derivative. 

Remarkably, owing to the extended ligand frame, these complexes show low-energy MLCT features, both in absorption and emission [92],... 

Because aryl phosphines are not only costly but can also act as aryl sources themselves, giving rise to unwanted byproducts, there has been steady interest in extending ligand-free Heck reactions to aryl bromides and aryl chlorides. Reetz and de Vries recently found that these can be performed with high efficiency using stabilized colloidal Pd catalysts [21]. If the palladium is kept at a low concentration between 0.01 and 0.1 mol%, precipitation of the Pd(0) is avoided and the colloids serve as a reservoir for the catalytically active species (Scheme 5). This economically attractive method has been successfully applied on an industrial scale by DSM [22]. 

By starting with some polyphthalonitrile precursors (e.g., (71) or 4,4 -oxybis(l,2-dicyanoben-zene), some extended ligands (e.g., (73) and (74)) (Scheme 17) can also be made successfully by the same route.58,59,139... 

Table VI - Mulliken atomic orbital populations and net charges for [VV XgXg]2- complexes from DV calculations. NR is nonrelativistic model R is relativistic. Angular momentum subshells j= 1/2, 3/2, 5/2 and an extended ligand basis set of valence ns, np, nd and (n+l)s optimized functions are indicated.

Probably, the most extended ligand-based method for the detection of ligand-macromolecule interactions is the saturation transfer difference (STD) experiment. In an STD experiment, a macromolecule resonance is selectively saturated (on-resonance) by irradiating the regions of the... 

Although they are a fairly new approach, hybrid methods have already been adopted for industrial catalyst research and have become an indispensable tool for quickly but reliably evaluating the effects of changes in an extended ligand system on the reactivity and selectivity of a catalyst. 

Currently, mesoMOFs are mainly synthesized by solvothermal method. Microwave-assisted strategy has also been reported for the fast synthesis of mesoMOFs. Although this approach is not often used, it provides an opportunity for high speed MOFs synthesis with possible size and morphology control. In addition, three different strategies have been reported for the design of mesoMOFs (i) synthesis of mesoMOFs by extended ligands and bulky SBUs (ii) template-directed synthesis hierarchical mesoMOFs and (iii) template-free synthesis hierarchical mesoMOFs. 

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