Backbone constitution

In recent years, there is no doubt that BINOL is one of the most extensively studied motifs. Incorporating a chiral binol unit into the chiral or achiral backbone constitutes a straightforward way in which to generate new chiral ligands [109]. 

Bidentate boranes with an o-phenylene backbone constitute some of the simplest examples of polydentate Lewis acids with rigid backbones. They can be prepared by the reaction of boron halides with a 1,2-dimetallated benzene derivative. Thus, the reaction of 1,2-bis(chloromercurio)benzene (5) with boron trichloride affords 1,2-bis(dichloroboryl)benzene (6, Scheme 3). ... 

Among the well known polymers, the ozonolysis of PVC was subject to a great number of studies, especially by A. Michel et al. [113-115]. These authors showed that the sensitivity of this polymer depends closely at first on the temperature, and also on the structure of the starting polymer, and thus, on its way of synthesis. So, the presence of double bonds on the polymer backbone constitutes a weak point which will constitute the starting step of the degradation leading to a very quick decrease in molecular weights. 

Two kinds of monomers are present in acryUc elastomers backbone monomers and cure-site monomers. Backbone monomers are acryUc esters that constitute the majority of the polymer chain (up to 99%), and determine the physical and chemical properties of the polymer and the performance of the vulcanizates. Cure-site monomers simultaneously present a double bond available for polymerization with acrylates and a moiety reactive with specific compounds in order to faciUtate the vulcanization process. 

A graft copolymer is a polymer that is comprised of molecules with one or more species of blocks connected as side chains to the backbone, having constitutional or configurational features different from those in the main chain. The simplest case of a graft copolymer can be represented as follows ... 

Methyl ketone 4 (Scheme 1), the right-wing sector of monensin (1), possesses nineteen of the twenty-six carbon atoms that constitute the backbone of the natural product. Compound 4 is distin-... 

A novel approach [98], proposed for generating starting configurations of amorphous dense polymeric systems, departs from a continuous vector field and its stream lines. The stream lines of continuous vector fields never intersect. If the backbones of linear polymer chains can be associated with such stream lines, the property of the stream lines partly alleviates the problem of excluded volume, which - due to high density and connectivity - constitutes the major barrier to an efficient packing method of dense polymeric systems. This intrinsic repulsive contact can be compared to an athermal hard-core potential. Considering stream lines immensely simplifies the problem. 

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