The Pt‐Organometallic Version of Perigraniline: Going Blue

Abstract

Four conjugated push-pull organometallic polymers ([Pt]-AQ)n ([Pt] = trans-bis(phenylacetylene)bis(tributylphosphine)platinum(II); AQ = 2-bromo-, 2,6-dibromo-, 2,6-diamino-, and unsubstituted anthraquinone diimine) were prepared and characterized by UV-vis spectroscopy and electrochemistry. A low-energy charge transfer, CT, band ([Pt]*→AQ; confirmed by density functional theory calculations), was found in the 445-500 nm window rather than the expected red-shifted range above 630 nm. X-ray structures of four model compounds reveal that steric hindrance induces large dihedral angles between the C6 H4 and NCC2 planes, rendering π-orbital overlap difficult between the [Pt] and AQ units. The position of the CT band is mainly driven the reduction potential of the anthraquinone diimine unit.

Drastic Tuning of the Photonic Properties of «(Push–Pull)n» trans‐Bis(ethynyl)bis(Tributylphosphine)Platinum(II)‐Containing Polymers

“…Recently, the strategy to increase the efficiency of bulk heterojunction solar cells based on conjugated polymer was set on «(push–pull) n » structures . In this respect, our group used appropriately substituted quinonediimines ( QN 2 ) and anthraquinone diimines ( AQN 2 ) as tunable electron acceptors connected to trans ‐bis(ethynyl)bis‐(phosphine)platinum(II) as an electron‐rich unit, [Pt] , for the «(push–pull) n » design, and the photophysical properties of these tailored polymers ( P1a–e , P2a–c , P3 ; Scheme ) were thoroughly investigated . In all cases, the absorption spectra are characterized by a broad low‐energy charge transfer (CT) band arising from [Pt] → QN 2 or [Pt] → AQN 2 , which is highly sensitive to substitution and the structure of the acceptor, and higher energy π–π* features centered on the [Pt] chromophore.…”

Porous Carbons – Hyperbranched Polymers – Polymer Solvation

“…An increase in the pyrolysis temperature while other parameters remain constant increases the micropore volume [70]. Plasma pretreatment of PET with a microwave apparatus prior to carbonization showed positive results, which could help reduce the need for a subsequent activation step [71]. The use of these carbons as electrode material in supercapacitors has also been investigated by the group of researchers [72].…”

“…Choi et al [69] reported a self-controlled synthesis of hb-PAEKs from diphenyl ether (or 1,4-diphenoxybenene, B 2 ) and trimesic acid (A 3 ) via the Friedel-Crafts reaction. Baek and coworkers developed optimized conditions for Friedel-Crafts acylation in poly(phosphoric acid)/phosphorus pentoxide (PPA/P 2 O 5 ) medium for the preparation of hb-PAEKs [70,71]. Martinez and Hay [72,73] proposed the efficient synthesis and characterization of hb poly(aryl ether sulfone)s with a K 2 CO 3 /Mg(OH) 2 catalyst system for nucleophilic aromatic substitution.…”

“…In this case, hydroquinone is part of the main chain [63] although side-chain polyhydroquinones also exist [64,65]. Anthraquinonebased polymers, which can be connected in various ways, are known [66][67][68][69][70][71]. These are rather peculiar examples of redox-sensitive polymers because the electrochemical reaction does not necessarily change the polymer's net charge upon full oxidation/reduction (because the oxidized units release protons).…”

“…At the same time, solubility changes are expected to be less affected by the change in the oxidation state, unless other effects play a role (e.g., hydrogen bonding). These quinone-related polymers have been described as possible energy storage materials [10,[71][72][73][74][75].…”