Macrocyclic Donor‐Acceptor Dyads Composed of Oligothiophene Half‐Cycles and Perylene Bisimides

Abstract

A series of donor‐acceptor (D−A) macrocyclic dyads consisting of an electron‐poor perylene bisimide (PBI) π‐scaffold bridged with electron‐rich α‐oligothiophenes bearing four, five, six and seven thiophene units between the two phenyl‐imide substituents has been synthesized and characterized by steady‐state UV/Vis absorption and fluorescence spectroscopy, cyclic and differential pulse voltammetry as well as transient absorption spectroscopy. Tying the oligothiophene strands in a conformationally fixed macrocyclic arrangement leads to a more rigid π‐scaffold with vibronic fine structure in the respective absorption spectra. Electrochemical analysis disclosed charged state properties in solution which are strongly dependent on the degree of rigidification within the individual macrocycle. Investigation of the excited state dynamics revealed an oligothiophene bridge size‐dependent fast charge transfer process for the macrocyclic dyads upon PBI subunit excitation.

Water‐Soluble Doubly‐Strapped Isolated Perylene Diimide Chromophore

“…In the past decade, some chromophore derivatives enclosed by alkylene straps on both sides have been synthesized to restrict their self-aggregation in the solid state or organic solvents. [25][26][27][28][29][30][31][32] More recently, Würthner [33] and Bronstein [34] reported two PDI dyes shielded by oligothiophene and alkoxybenzene straps respectively, whereas unfortunately both are water-insoluble and non-fluorescent. Inspired by these doubly-strapped structures and our previous work on water-soluble cyclophane, [35] we envisioned that the use of suitable cationic aromatic subunits as molecular straps to replace those hydrophobic groups could fabricate a novel PDI analogue, which may possess i) high water solubility available for biological systems, ii) sterically hindered chromophores to achieve intrinsic fluorescence and enhanced stability of radical species, and iii) sufficient structural robustness by covalent linkage.…”

Oligothiophene‐Ring‐Strapped Perylene Bisimides: Functionalizable Coaxial Donor–Acceptor Macrocycles

“…As compared to other reported macrocycles, the yields of the present systems are significantly high. [50][51][52][53] All the synthesized molecules were characterized by 1 H and 13 C NMR spectroscopy and matrixassisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). A detailed 2D NMR study sheds light on the possible cross-coupling between the various proton and nullifies any interaction between the hydrogen atoms of the thiophene ring and the PBI units (Figures S1-S8).…”

“…[50,51] However, a completely donor-strapped PBI remained unexplored until Würthner and co-workers reported macrocyclic D-A dyads formed by imide functionalization of PBI with a cyclic oligothiophene through a platinum-mediated cross-coupling reaction. [52,53] In all these oligothiophene-PBI macrocycles, the yield was only moderate. [50][51][52][53] Interestingly, the macrocyclic dyad exhibited ultrafast ET within approximately 1 ps from the donor oligothiophene to the acceptor PBI.…”

“…[52,53] In all these oligothiophene-PBI macrocycles, the yield was only moderate. [50][51][52][53] Interestingly, the macrocyclic dyad exhibited ultrafast ET within approximately 1 ps from the donor oligothiophene to the acceptor PBI. Through suitable placement of the donor-acceptor units in the dyad, fast charge recombination within 8-12 ps was observed.…”

POSS-containing polynorbornene with pendant perylene diimide: from a unique supramolecular structure to tunable luminescence properties

“…Perylene diimide (PDI) derivatives are a class of important chromophore groups, whose extended p-conjugation systems lead to many optical and electronic applications. [1][2][3][4][5][6][7][8][9][10] To develop functional polymer materials with different nanostructures and photovoltaic performance, much research has been focused toward introducing PDI molecules to main-chain polymers or block copolymers. [11][12][13][14][15] Moreover, the PDI side-chain polymer has more potential to combine the desirable photoelectric properties of PDIs with the mechanical strength and film forming properties of polymers due to their self-assembling ability.…”