Synthesis and applications of new poly(alkylene sulfide)s

Two projects are involved in this thesis; both of them are about the synthesis and applications of new poly(alkylene sulfide)s. The objective of the first project is the development of new polymeric borane reagents. The goal of second project is to introduce a new strategy for the synthesis of novel photochromic poly(alkylene sulfide)s. Chapter One Chapter One is an introductory chapter about borane chemistry. It involves a definition of the borane reagents, their uses in the most important applications and their development. Generally, this chapter shows the importance of borane reagents and the needs to develop convenient ones. Chapter Two Chapter Two includes a brief introduction about methods of synthesis of poly(alkylene sulfide)s. It shows how by following the most convenient procedure a number of poly(alkylene sulfide)s have been produced and from those polymers a couple of borane complexes were prepared. It also shows the stability, uses in different applications (reduction, hydroboration-oxidation and more sophisticated reaction) and the recycling of the polymeric material. In this chapter we report new poly(propylene sulfide)–borane complexes as convenient and versatile reagents for organic synthesis. Chapter Three Chapter Three is about photochromism and diarylethenes. It shows the reported synthetic strategies for the production of diarylperfluorocyclopentenes and their uses in the production of the different types of photochromic polymers which are very interesting materials that are used in a wide range of advanced applications. Chapter Four Chapter Four describes our attempt to develop a new route for the production of poly(alkylene sulfide)s bearing photochromic units. It shows the synthesis of a novel photochromic diarylperfluorocyclopentene aldehyde and the use of such material in the production of a model that resembles the target polymers. The synthesis of a novel photochromic oligomeric material is presented in this chapter

Poly(propylene sulfide)-borane: convenient and versatile reagent for organic synthesis

Poly(trimethylene sulfide)–borane adduct has been used as an efficient borane reagent in hydroboration reactions to produce various organoboranes, which have then been used without isolation in further reactions that involve single, double and triple migrations of alkyl groups. The presence of the polymer causes no problems, but there are practical advantages associated with its use, including lack of odour and easy recoverability

4-(5-{2-[5-(4-Cyanophenyl)-3-methylthiophen-2-yl]-3,3,4,4,5,5-hexafluorocyclopent-1-en-1-yl}-4-methylthiophen-2-yl)benzonitrile chloroform hemisolvate

The crystal structure of the title compound, C29H16F6N2S2·0.5CHCl3, consists of molecules with disordered perfluorocyclopentene rings [occupancy ratio 0.685 (3):0.315 (3)] and close F...F contacts (in the range 2.45-2.73 Å) between molecules. The short contacts are associated with the disorder. The dihedral angle between thiophene rings is 57.44 (8)°. The 5-(4-cyanophenyl)-3-methyl-2-thienyl groups of adjacent molecules are parallel, leading to zigzag chains of molecules along [101]. The dihedral angles between each thiophene ring and its adjacent cyanobenzene ring are 8.9 (2) and 7.15 (10)°