Molecular Recognition and Self-Assembling

Generally, molecular recognition and self-assembling of supermacromolecules exhibit the following features  

Compared with the molecular maintenance by covalent forces in traditional molecular chemistry, supermacromolecules obtained by controlling the bonds among molecules can make use of noncovalent forces to form self-assembling units of difierent atoms and molecules. The novel materials were developed by classical chemistry and supermacromolecular systems, and then assembled into the device, especially nanomaterials and their compositional device, which has a great significance in sustainable development for information technology, life science, novel material and ecosystem. 

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Reports of molecular recognition and self-assembly aspects of supramolecular chemistry associated with dendrimers and related structures will be the chief focus of this review. 

The exploitation of the reactivity of molecular crystals lies close to the origins of crystal engineering and is at the heart of the pioneering work of Schmidt [47a]. The idea is that of organizing molecules in the solid state using the principles of molecular recognition and self-assembly. Successful results have been obtained with bimolecular reactions, particularly [2+2] photoreactivity and cyclisation [47b,c]. Another important area is that of host-guest chemistry. 

Irregularly hyperbranched grafts provide a useful way to modify surfaces. A variety of chemistry can be used and a wide variety of grafts can be prepared. The hyperbranched grafts can serve as supported membranes, as catalyst supports or as substrates for further covalent graft chemistry. Functional groups within these interfaces can be readily modified by solution-state chemistry. The interfaces themselves can be used as media for further chemistry within the interface or as substrates in molecular recognition and self assembly of other macromolecules. 

For the synthetic chemist [14], the synthetic behavior of an assembler is akin to a molecule that functions as a template (Figure 2) [13], The pick-and-place paradigm evoked by an assembler [1] suggests a molecule that grabs and positions two molecules for a reaction that leads to a covalent bond. Moreover, such structure behavior is reminiscent of a linear template, a ditopic molecule that juxtaposes, by way of molecular recognition and self-assembly [5], two molecules linearly to achieve a particular linking of atoms. 

Saladino, Raffaele, Molecular Recognition and Self-Assembly Between Amines and Alcohols (Supraminols), 7, 77. 

Hanessian, S., Gomtsyan, A., Simard, M., and Roelens, S., Molecular recognition and self-assembly by weak hydrogen bonding Unprecedented supramolecular helicate structures from diamine/diol motifs, J. Am. Chem. Soc. 116, 4495 496 (1994). 

There are excellent reviews that address the structures of finite molecular assemblies.3 The literature principally involves molecular assemblies designed, constructed, and characterized in the liquid phase. This is unsurprising since interests in finite molecular assemblies largely originate from studies of molecular recognition and self-assembly phenomena in solution. 

The molecular assemblies described above have inspired us, in recent years, to develop finite assemblies in the solid state that exhibit chemical reactivity. Specifically, we,69 and others,70 have been utilizing principles of molecular recognition and self-assembly to develop a method to direct the formation of covalent bonds in organic solids. The method builds on the work of Schmidt on the reactivity of cinnamic acids in the organic solid state.45 Specifically, Schmidt has described topochemical postulates that dictate geometry criteria for a [2 + 2] photodimerization to occur in a solid. The postulates state that two carbon-carbon double (C=C) bonds should be aligned in parallel and separated by a distance <4.2 A to react. 

Currently, in the research of CD supermolecule chemistry, besides constant synthesis of new CD derivatives and studying interactions between CDs and guest molecules, new progress has been achieved in the following aspects such as CD molecular recognition and self-assembly, rotaxane design and multi-rotaxane... 

Hanessian. S. Siniard. M. Roelens. S. Molecular recognition and self-assembly by non-amidic hydrogen-bond- 32. 

Stoddart. F.J. Tseng, H.-R. Chemical synthesis gets a fillip from molecular recognition and self-assembly processes. Proc. Natl. Acad. Sci. U. S. A. 2002. 99 (8). 4778-4781. 

Harnessing entropically controlled phenomena, such as molecular recognition and self-assembly, can also result in energy savings. After all, it is because of intermolecular interactions that nature is able to produce such highly complicated and organized structures as biomacromolecules at ambient temperature and in aqueous media. 

Harnessing bioinspired phenomena such as molecular recognition and self-assembly, a new approach termed Non-Covalent Derivatization was developed. The properties of hydroquinone were successfully altered by incorporating the hydroquinone molecules in a matrix with compatible alkylterephthalamide molecules. This was achieved via one-step solventless... 

Pollution Prevention via Molecular Recognition and Self Assembly Non-Covalent Derivatization. Warner, J. C., in Green Chemistry Frontiers in Benign Chemical Synthesis and Processes Anastas, P. and Williamson, T. Eds., Oxford University Press, London, pp 336 - 346. 1998. 

During the past 20 years, mechanically interlocked molecules, known as catenanes and rotaxanes, many of them redox-active, have become readily accessible using template-directed protocols that rely upon the precepts of molecular recognition and self-assembly and the tenets of supramolecular assistance to covalent synthesis. By incorporating different recognition units with dissimilar redox properties into appropriate components, these compounds can often be induced to switch hysteretically between ground and metastable co-con-... 

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