The Building-block Methodology

Coordination Polymer Design Approaches 2.4.3.1 The Building-block Methodology 

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Reaction solvent can also have a more subtle effect upon coordination polymer reactions, and this is discussed in more detail below. However, in terms of the building-block methodology, if a solvent is particularly effective at binding and solvating a cation, it has been noticed that the metal cation can be kept back from participating in coordination polymer formation the choice of solvent can thus influence the polymer product stoichiometry [47]. 

There are many excellent reviews " outlining the plethora of structural and material properties of MOFs, but this chapter focuses on the incorporation of photoactive components within MOFs. The opportunities to incorporate photoactive species within frameworks are readily achievable when one considers the building-block methodology and the plethora of metal cations and ligands that can be exploited. Although it is possible to simply incorporate fluorescent metal cations, such as lanthanides or ligands, these systems have been excellently reviewed recently. Similarly, photodimerization of ligands within MOFs has also been extensively reviewed and will not be... 

Exploiting the building-block methodology, it is easy to envisage the inclusion of chemical moieties within the framework structure whose photochemical properties can be modified by guest inclusion. In principal, any selectivity of guest inclusion induced by the framework structure can be used to prepare MOFs that can act as selective sensors for guest species. This approach has been demonstrated by a number of examples for a variety of... 

The building block methodology is recognized as one of the most reliable synthetic strategies in addition to a direct tri-fluoromethylation methodology. Generally speaking. 

Johnson s interpretation of MES concepts is known as Events Causal Factor Charting (E CF), or Causal Factor Charting for short, and has been adopted as one of the building blocks of several methodologies for process safety incident investigation. 

Several sophisticated techniques and data analysis methodologies have been developed to measure the RTD of industrial reactors (see, for example, Shinnar, 1987). Various different types of models have been developed to interpret RTD data and to use it further to predict the influence of non-ideal behavior on reactor performance (Wen and Fan, 1975). Most of these models use ideal reactors as the building blocks (except the axial dispersion model). Combinations of these ideal reactors with or without by-pass and recycle are used to simulate observed RTD data. To select an appropriate model for a reactor, the actual flow pattern and its dependence on reactor hardware and operating protocol must be known. In the absence of detailed quantitative models to predict the flow patterns, selection of a model is often carried out based on a qualitative understanding of flow patterns and an analysis of observed RTD data. It must be remembered that more than one model may fit the observed RTD data. A general philosophy is to select the simplest model which adequately represents the physical phenomena occurring in the actual reactor. 

Various cyclization processes traditionally used in the synthesis of hydrocarbon heterocycles and it is not surprising that this methodology is popular for the preparation of fluoroalkyl analogues. These methods are included in second subgroup of synthetic transformations used for the preparation of fluoroalkylated heterocycles. Usually, these are multicomponent reactions and one of the building blocks contains a fluoroalkyl group, which ends up into the synthesized heterocycle. 

When the methodology of stereoselective synthesis was still in its infancy, it was considered advantageous to utilize sequences of stereogenic centers available from enantiomerically pure natural products as building blocks [3, 4] this so-called chiral pool synthesis strategy is exemplified in Scheme 4.2. The bicyclic acetal structure of exo-brevicomin (31) can be ret-rosynthetically linked to the chiral ketodiol 32, which can be derived from (S,S)-(-)-tartaric acid, a readily available chiral starting material. This leads to the building block oriented bond-set depicted in intermediate 32. 

More recently, the same group proposed a new methodology for the synthesis of exact graft copolymers composed of PMMA and five PS branches [231]. For this synthesis, a specially designed hving AB diblock copolymer (PS-b-PMMA), in-chain-functionahzed with a 3-tert-butyldimethylsilyloxymethylphenyl (SiOMP) group, is used as the building block unit (Scheme 5.23). In this case, three reaction steps are employed in an iterative synthetic sequence ... 

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