Charge Resonance and Photoinduced Charge Transfer in Bis(N,N-dimethylaminophenyl-tetracyanobutadiene)-diketopyrrolopyrrole Multimodular System.

Intervalence charge transfer (IVCT) or charge resonance is often observed in redox-active systems encompassed of two identical electroactive groups, where one of the groups is either oxidized or reduced and serves as a model system to improve our fundamental understanding of charge transfer. This property has been explored in the present study in a multimodular push-pull system carrying two N,N-dimethylaminophenyl-tetracyanobutadiene (DMA-TCBD) entities covalently linked to the opposite ends of bis(thiophenyl)diketopyrrolopyrrole (TDPP). Electrochemical or chemical reduction of one of the TCBDs promoted electron resonance between them, exhibiting an IVCT absorption peak in the near-infrared area. The comproportionation energy, -ΔGcom, and equilibrium constant, Kcom, evaluated from the split reduction peak were, respectively, 1.06 × 104 J/mol and 72.3 M-1. Excitation of the TDPP entity in the system promoted the thermodynamically feasible sequential charge transfer and separation of charges in benzonitrile, wherein the IVCT peak formed upon charge separation served as a signature peak in characterizing the product. Further, transient data analyzed using Global Target Analysis revealed the charge separation to take place in a ps time scale (k ∼ 1010 s-1) as a result of close positioning and strong electronic interaction between the entities. The significance of IVCT in probing excited-state processes is evidenced by the present study.

[1]  F. D’Souza,et al.  Near-IR Charge Transfer in Strongly Interacting Diphenothiazone-TCBD and Diphenothiazine-DCNQ Push-Pull Triads. , 2022, Chemistry.

[2]  F. D’Souza,et al.  Does Location of BF2-Chelated Dipyrromethene (BODIPY) Ring Functionalization Affect Spectral and Electron Transfer Properties? Studies on α-, β-, and Meso-Functionalized BODIPY-Derived Donor–Acceptor Dyads and Triads , 2021, The Journal of Physical Chemistry C.

[3]  F. D’Souza,et al.  Photoinduced Charge Separation Prompted Intervalence Charge Transfer in a Bis(thienyl)diketopyrrolopyrrole Bridged Donor‐TCBD Push‐Pull System , 2021, Angewandte Chemie.

[4]  F. D’Souza,et al.  Symmetric and Asymmetric Push-Pull Conjugates: Significance of Pull Group Strength on Charge Transfer and Separation. , 2021, The journal of physical chemistry. B.

[5]  F. D’Souza,et al.  Charge stabilization via electron exchange: excited charge separation in symmetric, central triphenylamine derived, dimethylaminophenyl–tetracyanobutadiene donor–acceptor conjugates , 2020, Chemical science.

[6]  F. D’Souza,et al.  Interfacing High-Energy Charge Transfer States to a Near-IR Sensitizer for Efficient Electron Transfer upon Near-IR Irradiation. , 2020, Angewandte Chemie.

[7]  F. D’Souza,et al.  Formation of Highly Efficient, Long-Lived Charge Separated States in Star-Shaped Ferrocene-Diketopyrrolopyrrole-Triphenylamine Donor-Acceptor-Donor Conjugates. , 2020, Chemistry.

[8]  F. D’Souza,et al.  Excited State Electron Transfer in 1,1,4,4-Tetracyanobuta-1,3-Diene (TCBD)- and Cyclohexa-2,5-Diene-1,4-Diylidene-Expanded TCBD-Substituted BODIPY-Phenothiazines Donor-Acceptor Conjugates. , 2020, Chemistry.

[9]  L. Lemiègre,et al.  Synthesis, characterization and unusual near-infrared luminescence of 1,1,4,4-tetracyanobutadiene derivatives. , 2020, Chemical communications.

[10]  S. Mandal,et al.  Substituent enhanced fluorescence properties of star α-cyanostilbenes and their application in bioimaging. , 2019, Journal of materials chemistry. B.

[11]  D. Guldi,et al.  Subphthalocyanine–tetracyanobuta-1,3-diene–aniline conjugates: stereoisomerism and photophysical properties† †This article is dedicated to Prof. Michael R. Wasielewski on the occasion of his 70th birthday. ‡ ‡Electronic supplementary information (ESI) available: Procedures for synthesis, characteriz , 2019, Chemical science.

[12]  F. D’Souza,et al.  Conversion of Large-Bandgap Triphenylamine–Benzothiadiazole to Low-Bandgap, Wide-Band Capturing Donor–Acceptor Systems by Tetracyanobutadiene and/or Dicyanoquinodimethane Insertion for Ultrafast Charge Separation , 2019, The Journal of Physical Chemistry C.

[13]  F. D’Souza,et al.  Strong Ground- and Excited-State Charge Transfer in C3 -Symmetric Truxene-Derived Phenothiazine-Tetracyanobutadine and Expanded Conjugates. , 2019, Angewandte Chemie.

[14]  K. Mikkelsen,et al.  Donor−Acceptor-Functionalized Subphthalocyanines for Dye-Sensitized Solar Cells , 2018, ChemPhotoChem.

[15]  F. D’Souza,et al.  Ultrafast Charge-Separation in Triphenylamine-BODIPY-Derived Triads Carrying Centrally Positioned, Highly Electron-Deficient, Dicyanoquinodimethane or Tetracyanobutadiene Electron-Acceptors. , 2017, Chemistry.

[16]  D. Guldi,et al.  Subphthalocyanines Axially Substituted with a Tetracyanobuta-1,3-diene-Aniline Moiety: Synthesis, Structure, and Physicochemical Properties. , 2017, Journal of the American Chemical Society.

[17]  M. Wasielewski,et al.  Singlet Fission via an Excimer-Like Intermediate in 3,6-Bis(thiophen-2-yl)diketopyrrolopyrrole Derivatives. , 2016, Journal of the American Chemical Society.

[18]  Victor Guallar,et al.  Ecoupling server: A tool to compute and analyze electronic couplings , 2016, J. Comput. Chem..

[19]  F. Diederich,et al.  Intense Ground-State Charge-Transfer Interactions in Low-Bandgap, Panchromatic Phthalocyanine-Tetracyanobuta-1,3-diene Conjugates. , 2016, Angewandte Chemie.

[20]  M. Wasielewski,et al.  Effects of Crystal Morphology on Singlet Exciton Fission in Diketopyrrolopyrrole Thin Films. , 2016, The journal of physical chemistry. B.

[21]  D. Gryko,et al.  Diketopyrrolopyrroles: Synthesis, Reactivity, and Optical Properties , 2015 .

[22]  Joydeep Dhar,et al.  Herringbone to cofacial solid state packing via H-bonding in diketopyrrolopyrrole (DPP) based molecular crystals: influence on charge transport. , 2015, Chemical communications.

[23]  Ifor D. W. Samuel,et al.  Determining the optimum morphology in high-performance polymer-fullerene organic photovoltaic cells , 2013, Nature Communications.

[24]  Satish Patil,et al.  Diketopyrrolopyrrole‐based conjugated polymers and small molecules for organic ambipolar transistors and solar cells , 2013 .

[25]  Daoben Zhu,et al.  A Solution‐Processable Small Molecule Based on Benzodithiophene and Diketopyrrolopyrrole for High‐Performance Organic Solar Cells , 2013 .

[26]  Yongfang Li,et al.  A Solution‐Processable Electron Acceptor Based on Dibenzosilole and Diketopyrrolopyrrole for Organic Solar Cells , 2013 .

[27]  Katharine M. Mullen,et al.  Glotaran: A Java-Based Graphical User Interface for the R Package TIMP , 2012 .

[28]  Yongfang Li,et al.  A 3D star-shaped non-fullerene acceptor for solution-processed organic solar cells with a high open-circuit voltage of 1.18 V. , 2012, Chemical communications.

[29]  K. Ho,et al.  Synthesis and applications of novel low bandgap star-burst molecules containing a triphenylamine core and dialkylated diketopyrrolopyrrole arms for organic photovoltaics , 2012 .

[30]  Daoben Zhu,et al.  Diketopyrrolopyrrole-containing quinoidal small molecules for high-performance, air-stable, and solution-processable n-channel organic field-effect transistors. , 2012, Journal of the American Chemical Society.

[31]  C. Lambert,et al.  Organic mixed-valence compounds: a playground for electrons and holes. , 2012, Angewandte Chemie.

[32]  O. Wenger,et al.  Organic mixed valence. , 2011, Chemical reviews.

[33]  T. Michinobu.  Adapting semiconducting polymer doping techniques to create new types of click postfunctionalization. , 2011, Chemical Society reviews.

[34]  Takhee Lee,et al.  Single Molecule Electronic Devices , 2011, Advanced materials.

[35]  F. Würthner,et al.  Synthesis and characterization of optical and redox properties of bithiophene-functionalized diketopyrrolopyrrole chromophores. , 2011, The Journal of organic chemistry.

[36]  F. Diederich,et al.  Unprecedented thermal rearrangement of push-pull-chromophore-[60]fullerene conjugates: formation of chiral 1,2,9,12-tetrakis-adducts. , 2010, Chemical communications.

[37]  Michio Yamada,et al.  Optical stability of axially chiral push-pull-substituted buta-1,3-dienes: effect of a single methyl group on the C60 surface. , 2010, Angewandte Chemie.

[38]  Thuc-Quyen Nguyen,et al.  Nanoscale Phase Separation and High Photovoltaic Efficiency in Solution‐Processed, Small‐Molecule Bulk Heterojunction Solar Cells , 2009 .

[39]  Chain‐Shu Hsu,et al.  Synthesis of conjugated polymers for organic solar cell applications. , 2009, Chemical reviews.

[40]  T. Iwamoto,et al.  Reactions between 1‐Ethynylazulenes and 7,7,8,8‐Tetracyanoquinodimethane (TCNQ): Preparation, Properties, and Redox Behavior of Novel Azulene‐Substituted Redox‐Active Chromophores , 2009 .

[41]  Yang Yang,et al.  Bandgap and Molecular Level Control of the Low-Bandgap Polymers Based on 3,6-Dithiophen-2-yl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione toward Highly Efficient Polymer Solar Cells , 2009 .

[42]  Yong Cao,et al.  Development of novel conjugated donor polymers for high-efficiency bulk-heterojunction photovoltaic devices. , 2009, Accounts of chemical research.

[43]  M. Ratner,et al.  When things are not as they seem: quantum interference turns molecular electron transfer "rules" upside down. , 2008, Journal of the American Chemical Society.

[44]  Taku Shoji,et al.  Synthesis and Redox Behavior of 1-Azulenyl Sulfides and Efficient Synthesis of 1,1′-Biazulenes , 2008 .

[45]  F. Diederich,et al.  Charge-transfer chromophores by cycloaddition-retro-electrocyclization: multivalent systems and cascade reactions. , 2007, Angewandte Chemie.

[46]  F. Diederich,et al.  Donor‐Substituted 1,1,4,4‐Tetracyanobutadienes (TCBDs): New Chromophores with Efficient Intramolecular Charge‐Transfer Interactions by Atom‐Economic Synthesis. , 2006 .

[47]  D. D’Alessandro,et al.  Intervalence charge transfer (IVCT) in trinuclear and tetranuclear complexes of iron, ruthenium, and osmium. , 2006, Chemical reviews.

[48]  Jan W. Verhoeven,et al.  On the role of spin correlation in the formation, decay, and detection of long-lived, intramolecular charge-transfer states , 2006 .

[49]  F. Diederich,et al.  A New Class of Organic Donor—Acceptor Molecules with Large Third‐Order Optical Nonlinearities. , 2005 .

[50]  S. Lindeman,et al.  Intervalence (charge-resonance) transitions in organic mixed-valence systems. Through-space versus through-bond electron transfer between bridged aromatic (redox) centers. , 2003, Journal of the American Chemical Society.

[51]  T. Meyer,et al.  The localized-to-delocalized transition in mixed-valence chemistry. , 2001, Chemical reviews.

[52]  W. Kaim,et al.  Exploration of mixed-valence chemistry: inventing new analogues of the Creutz-Taube ion. , 2000, Accounts of chemical research.

[53]  Nelsen.  "Almost delocalized" intervalence compounds , 2000, Chemistry.

[54]  B. Brunschwig,et al.  Energy surfaces, reorganization energies, and coupling elements in electron transfer , 1999 .

[55]  R. Ismagilov,et al.  Adiabatic electron transfer: comparison of modified theory with experiment. , 1997, Science.

[56]  M. Ward.  Metal-metal interactions in binuclear complexes exhibiting mixed valency; molecular wires and switches , 1995 .

[57]  G. Bold,et al.  Enantioselective Synthesis of D‐threo‐β‐Hydroxy‐α‐amino Acids with Titanium‐Carbohydrate Complexes , 1989 .

[58]  H. Langhals,et al.  The Influence of Packing Effects on the Solid‐State Fluorescence of Diketopyrrolopyrroles , 1989 .

[59]  D. Richardson,et al.  Mixed-valence molecules: Electronic delocalization and stabilization , 1984 .

[60]  Henry Taube,et al.  Binuclear complexes of ruthenium ammines , 1973 .

[61]  O. Howarth,et al.  Electron Spin Resonance Spectra of Monomeric and Dimeric Cation Radicals , 1970 .

[62]  Henry Taube,et al.  Direct approach to measuring the Franck-Condon barrier to electron transfer between metal ions , 1969 .

[63]  O. Howarth,et al.  Electron Spin Resonance Study of Mono- and Dimeric Cations of Aromatic Hydrocarbons1 , 1966 .

[64]  I. C. Lewis,et al.  Electron Spin Resonance of Radical Cations Produced by the Oxidation of Aromatic Hydrocarbons with SbCl5 , 1965 .

[65]  Antje Sommer,et al.  Principles Of Fluorescence Spectroscopy , 2016 .

[66]  M. Bryce.  Tetrathiafulvalenes as π‐Electron Donors for Intramolecular Charge‐Transfer Materials , 1999 .

[67]  D. Rehm,et al.  Kinetics of Fluorescence Quenching by Electron and H‐Atom Transfer , 1970 .