Unsymmetrical Polymeric Ladderphanes by Sequential Polymerization: A New Approach for the Template Synthesis of Polymers with Well‐Defined Chain Length and Narrow Polydispersity

Abstract

Nothing ROMP with that: Unsymmetrical double‐stranded ladderphanes are obtained by sequential ring‐opening metathesis polymerization and Glaser oxidation of norbornene appended with bisalkyne moieties. Hydrolysis of these ladderphanes gives substituted poly(m‐phenylene butadiynylene)s with narrow polymer dispersity index (PDI) and well‐controlled degree of polymerization.

Sequence information transfer using covalent template-directed synthesis

“…2 is applicable to the synthesis of macromolecules. [44][45][46] However, implementation of the scheme in Fig. 2 requires efficient orthogonal chemistry for selective attachment of two different types of monomer, zipping up the backbone, and cleavage of the product duplex.…”

Determination of the Orientation of Pendants on Rigid‐Rod Polymers

“…For the past two decades, we have extensively studied the chemistry of double stranded ladderphanes 1 and 2 (Scheme 1), [1][2][3][4][5] which are synthesized by ring opening metathesis polymerization (ROMP) of bisnorbornenes 3 [2] or biscyclobutenes 4 [3] respectively. Unsymmetrical double stranded ladderphanes 7 are obtained from a single stranded polynorbornene or polycyclobutene using replication procotol (5 to 7 via 6) [4] or sequential polymerization (8 to 7 via 6).…”

“…Unsymmetrical double stranded ladderphanes 7 are obtained from a single stranded polynorbornene or polycyclobutene using replication procotol (5 to 7 via 6) [4] or sequential polymerization (8 to 7 via 6). [5] The prerequisite for the successful synthesis of 1, 2 and 7 would depend on the alignment of all pendants in a single stranded polymers towards similar direction. In that regard, the adjacent pendants should be in close proximity.…”

Polynorbornene-based Template for Polymer Synthesis

“…Accordingly, 53a-c, obtained from ROMP of 52 in the presence of different amounts of 10, are treated with Cu(OAc) 2 and a stoichiometric amount of tetrabutylammonium fluoride (TBAF) to give 54a-c. Base-promoted hydrolysis of 54a-c affords the corresponding alt-poly(butadiynylene-mphenylene) 55a-c and 20 (eq 16). 50 Again, the degree of polymerization of 55a-c depends on the mol per cent of 10 used for the polymerization of 52 (Table 3).…”