Indacenodipyrene Containing Small Molecules and Ladder Polymers

A series of s-indaceno[1,2,3-cd:5,6,7-c'd']dipyrene-containing small molecule and ladder polymers were prepared using a palladium catalyzed arylation reaction. Precursor polymers and their resulting ladder polymers with molecular weights up to 13 kDa were prepared. The rigid, planar materials possessed highest occupied molecular orbital (HOMO) energies of -5.39 to -5.23 eV, lowest unoccupied molecular orbitals (LUMO) energies of -2.42 eV to -2.98 eV, and optical gaps of 1.68 to 2.03 eV. Organic field effect transistors were prepared with derivatives giving hole mobilities up to 2.5 X 10-5 cm2V-1s-1.

Synthesis of Single-Handed Helical Spiro-Conjugated Ladder Polymers through Quantitative and Chemoselective Cyclizations

<div>We report the unprecedented synthesis of one-handed helical spiro-conjugated ladder polymers with well-defined primary and secondary structures, in which the spiro-linked</div><div>dibenzo[a,h]anthracene fluorophores are arranged in a one-handed twisting direction, through quantitative and chemoselective acidpromoted intramolecular cyclizations of random-coil precursor polymers composed of chiral 1,1’-spirobiindane and achiral bis[2-(4-alkoxyphenyl)ethynyl]phenylene units. Intense circular dichroism (CD) and circularly polarized luminescence (CPL) were observed, whereas the precursor polymers exhibited negligible CD and CPL activities. The introduction of 2,6-dimethyl substituents on the 4- alkoxyphenylethynyl pendants is of key importance for this simple,</div><div>quantitative, and chemoselective cyclization. This strategy is applicable to the defect-free precise synthesis of other varieties of fully p-conjugated molecules and coplanar ladder polymers that have not been achieved before.</div>

Synthesis of Single-Handed Helical Spiro-Conjugated Ladder Polymers through Quantitative and Chemoselective Cyclizations

<div>We report the unprecedented synthesis of one-handed helical spiro-conjugated ladder polymers with well-defined primary and secondary structures, in which the spiro-linked</div><div>dibenzo[a,h]anthracene fluorophores are arranged in a one-handed twisting direction, through quantitative and chemoselective acidpromoted intramolecular cyclizations of random-coil precursor polymers composed of chiral 1,1’-spirobiindane and achiral bis[2-(4-alkoxyphenyl)ethynyl]phenylene units. Intense circular dichroism (CD) and circularly polarized luminescence (CPL) were observed, whereas the precursor polymers exhibited negligible CD and CPL activities. The introduction of 2,6-dimethyl substituents on the 4- alkoxyphenylethynyl pendants is of key importance for this simple,</div><div>quantitative, and chemoselective cyclization. This strategy is applicable to the defect-free precise synthesis of other varieties of fully p-conjugated molecules and coplanar ladder polymers that have not been achieved before.</div>

Synthesis of Reversibly Photocleavable Pseudo-Ladder Polymers

Design of stimuli-responsive polymers derived from reversibly cleavable main chains provides a strategy for fabricating smart materials with responsive properties and functions upon desired stimuli. Herein, we report the synthesis...