Optically Active Polysilylenes: State-of-the-Art Chiroptical Polymers

Chiral and Chirality Discrimination on Helical Polyacetylenes

“…1. These helical polymers can be classified into two types with respect to the nature of the helical conformation: that is a stable helical polymer (1 -3) even in solution and a dynamic helical polymer (4,5). Details of these helical polymers have been thoroughly reviewed elsewhere.…”

“…Details of these helical polymers have been thoroughly reviewed elsewhere. [1][2][3][4][5] Besides these helical polymers, we recently succeeded in inducing a conceptually new helicity on optically inactive polyacetylenes upon complexation with optically active small molecules capable of interacting with the polymers. This article describes our recent studies on helicity induction of polyacetylenes through noncovalent, chiral acid-base interactions together with chiral recognition ability of optically active polyacetylenes as a chiral stationary phase (CSP) for HPLC.…”

Synthesis and structure determination of helical polymers

“…Inspired by biological helices, such as DNA and proteins, chemists have been challenged to synthesize helical polymers with a controlled helical sense that aims not only to mimic biological helical structures but also to develop chiral materials for the separation of enantiomers and asymmetric catalysis. [1][2][3][4][5][6][7][8][9][10][11][12] The history of synthetic helical polymers with optical activity extends back to the 1960s when Pino and Lorenzi 13 investigated the structural and chiroptical properties of isotactic vinyl polymers prepared by the polymerization of a-olefins bearing optically active substituents. Although helical polyolefins are totally dynamic in nature and consist of short helical segments separated by frequently occurring helical reversals among disordered, random coil conformations, 14 this study was significant in the field of synthetic helical polymers, from which a number of helical polymers have been synthesized.…”

“…30 The details of their pioneering studies have been thoroughly reviewed elsewhere. [1][2][3][4][5][6][7][8][9][10][11][12]25,31,34 Although various helical polymers have been synthesized, particularly in the last decade, their exact helical structures, including helical pitch and helical sense (right-or left-handed helix), remain unsolved. The preferred-handed helix formation of most synthetic helical polymers has usually been based on circular dichroism (CD) and/or optical rotation measurements, which, however, may not be straightforward for proposing an unambiguous helical structure.…”

Single‐Handed Helical Carbonaceous Nanotubes: Preparation, Optical Activity, and Applications

“…The handedness and the stacking handedness of the polymer main chain could be controlled by the addition of chiral compounds. [44] Figure 8 indicates that left-and right-handed helical carbonaceous nanotubes could drive the polysilane (M w = 5.31 3 10 4 ; PDI = 1.12) main chains to stack in a right-and left-handed fashion, respectively. The bisigned CD couplet signals at 320 nm originated from electron transfer among the polysilane main chains.…”