Donor-substituted cyanoethynylethenes: pi-conjugation and band-gap tuning in strong charge-transfer chromophores.

An extensive series of silyl-protected cyanoethynylethenes (CEEs) and N,N-dimethylanilino donor-substituted CEEs have been synthesized. More extended chromophores were constructed by selective silyl deprotection and subsequent oxidative acetylenic coupling. The strong electron-accepting nature of the CEEs was revealed by a combination of 13C NMR spectroscopic and electrochemistry measurements. Donor-substituted CEEs display strong intramolecular charge-transfer (CT) character, resulting in intense, bathochromically shifted CT bands in the UV/Vis spectrum. Their structural diversity establishes them as suitable models for the study of pi-conjugation and band gap tuning in strong charge-transfer chromophores. The extent of pi-conjugation in the donor-substituted CEEs was investigated by a combination of ground-state techniques, such as X-ray crystallography, electrochemistry, B3 LYP calculations, and NMR spectroscopy. The comparison of these ground-state results with the features observed in the UV/Vis spectra reveals that-contrary to expectations-more extensive pi-conjugation can lead to larger band gaps in molecules with strong donor and acceptor moieties.

[1]  Ivan Biaggio,et al.  A new class of organic donor-acceptor molecules with large third-order optical nonlinearities. , 2005, Chemical communications.

[2]  F. Diederich,et al.  Synthesis of 1,4-Diethynyl- and 1,1,4,4-Tetraethynylbutatrienes , 2004 .

[3]  K. Houk,et al.  How large is the conjugative stabilization of diynes? , 2004, Journal of the American Chemical Society.

[4]  N. Matsunaga,et al.  On the lack of conjugation stabilization in polyynes (polyacetylenes). , 2004, The Journal of organic chemistry.

[5]  F. Diederich,et al.  Limitations on the use of UV/Vis spectroscopy for the evaluation of conjugation effectiveness. , 2004, Organic & biomolecular chemistry.

[6]  F. Diederich,et al.  Redox Properties of Linear and Cyclic Scaffolds Based on Di‐ and Tetraethynylethene , 2004 .

[7]  F. Diederich,et al.  Donor‐Substituted Perethynylated Dehydroannulenes and Radiaannulenes: Acetylenic Carbon Sheets Featuring Intense Intramolecular Charge Transfer , 2004 .

[8]  Louisa Dalton.  CHEMISTS WHO UNRAVEL CRIMES , 2004 .

[9]  H. Meier,et al.  Red‐ and Blue‐Shifts in Oligo(1,4‐phenyleneethynylene)s Having Terminal Donor−Acceptor Substitutions , 2004 .

[10]  H. Meier,et al.  Extension of conjugation leading to bathochromic or hypsochromic effects in OPV series. , 2004, Chemistry.

[11]  James N. Wilson,et al.  Cruciform pi-systems: hybrid phenylene-ethynylene/phenylene-vinylene oligomers. , 2003, Chemical communications.

[12]  F. Diederich,et al.  Donor-substituted peralkynylated "radiaannulenes": novel all-carbon macrocycles with an intense intramolecular charge-transfer. , 2003, Chemical communications.

[13]  N. Matsunaga,et al.  The conjugation stabilization of 1,3-butadiyne is zero. , 2003, Organic letters.

[14]  F. Diederich,et al.  Donor-substituted cyanoethynylethenes: powerful chromophores for opto-electronic applications. , 2003, Organic & biomolecular chemistry.

[15]  B. Strehmel,et al.  The Influence of σ and π Acceptors on Two‐Photon Absorption and Solvatochromism of Dipolar and Quadrupolar Unsaturated Organic Compounds , 2003 .

[16]  F. Diederich,et al.  Cyanoethynylethenes: A Class of Powerful Electron Acceptors for Molecular Scaffolding We thank the ETH Research Council and the Fonds der Chemischen Industrie for their support of this work. Robin Gist is acknowledged for the supply of starting materials. , 2002 .

[17]  F. Diederich,et al.  Cyanoethynylethenes: a class of powerful electron acceptors for molecular scaffolding. , 2002, Angewandte Chemie.

[18]  Ulrich Gubler,et al.  Molecular Design for Third-Order Nonlinear Optics , 2002 .

[19]  P. Günter,et al.  Highly functionalized dimeric tetraethynylethenes and expanded radialenes: strong evidence for macrocyclic cross-conjugation. , 2001, Chemistry.

[20]  G. Hammond,et al.  An improved preparation of α-fluorinated propargylphosphonates and the solid phase synthesis of α-hydroxy-γ-TIPS propargylphosphonate ester , 2001 .

[21]  F. Diederich.  Carbon-rich acetylenic scaffolding: rods, rings and switches , 2001 .

[22]  François Diederich,et al.  Acetylenkupplungen: eine leistungsfähige Methode für den Aufbau von Molekülen , 2000 .

[23]  Diederich,et al.  Acetylenic Coupling: A Powerful Tool in Molecular Construction. , 2000, Angewandte Chemie.

[24]  F. Diederich,et al.  Donor-Acceptor-Functionalized Tetraethynylethenes with Nitrothienyl Substituents: Structure-Property Relationships , 2000 .

[25]  Wei Ji,et al.  Determination of nonlinear absorption and refraction by single Z-scan method , 2000 .

[26]  Paras N. Prasad,et al.  New Class of Two-Photon-Absorbing Chromophores Based on Dithienothiophene , 2000 .

[27]  Carlos Díaz,et al.  TCNE and TCNQ ligands as efficient bridges in mixed-valence complexes containing iron–cyclopentadienyl and other organometallic systems , 2000 .

[28]  Joel S. Miller,et al.  Identification of [MII(Arene)2]2+ (M = V, Cr) as the Key Intermediate in the Formation of V[TCNE]x·ySolvent Magnets and Cr[TCNE]x·Solvent , 2000 .

[29]  B. Iorga,et al.  Carbanionic displacement reactions at phosphorus. Part III. Cyanomethylphosphonate vs. cyanomethylenediphosphonate. Synthesis and solid-state structures , 2000 .

[30]  F. Diederich,et al.  CYCLIC AND LINEAR ACETYLENIC MOLECULAR SCAFFOLDING , 1999 .

[31]  S. Gibson,et al.  2,4,6-triarylchalcogenopyrylium dyes related in structure to the antitumor agent AA1 as in vitro sensitizers for the photodynamic therapy of cancer. , 1999, Journal of medicinal chemistry.

[32]  A. Oseroff,et al.  Synthesis and evaluation of chalcogenopyrylium dyes as potential sensitizers for the photodynamic therapy of cancer. , 1999, Journal of medicinal chemistry.

[33]  F. Diederich,et al.  One- and two-dimensionally conjugated tetrathynylethenes: Structure versus second-order optical polarizabilities , 2002, Technical Digest. 1998 EQEC. European Quantum Electronics Conference (Cat. No.98TH8326).

[34]  F. Diederich,et al.  Two-dimensionally conjugated molecules: The importance of low molecular symmetry for large third-order nonlinear optical effects , 1998 .

[35]  Rik R. Tykwinski,et al.  Structure−Property Relationships in Third-Order Nonlinear Optical Chromophores , 1998 .

[36]  J. Warman,et al.  Excited State Localization or Delocalization in C3-symmetric Amino-substituted Triphenylbenzene Derivatives , 1998 .

[37]  A. Punzi,et al.  One-step synthesis of dialkynyl-1,2-diones and their conversion to fused pyrazines bearing enediyne units , 1997 .

[38]  Rainer E. Martin,et al.  Electronic Characteristics of Arylated Tetraethynylethenes: A Cooperative Computational and Electrochemical Investigation , 1997 .

[39]  F. Diederich,et al.  Donor/Acceptor‐Substituted Tetraethynylethenes: Systematic Assembly of Molecules for Use as Advanced Materials , 1996 .

[40]  F. Diederich,et al.  Towards the Synthesis of Tetraethynylallene , 1996 .

[41]  F. Diederich,et al.  Donor–acceptor substituted tetraethynylethenes , 1996 .

[42]  F. Diederich,et al.  Electrochemical properties of tetraethynylethenes, fully cross-conjugated Π-chromophores, and tetraethynylethene-based carbon-rich molecular rods and dehydroannulenes , 1995 .

[43]  J. Heinze,et al.  Synthesis and electrochemical properties of 4‐phenyl‐1‐buten‐3‐yne‐1,1,2‐tricarbonitriles and tricyanoacrylates , 1995 .

[44]  P. Suppan,et al.  Solvatochromic shifts of non-dipolar molecules in polar solvents , 1995 .

[45]  F. Diederich,et al.  Tetraethynylethenes: Fully cross-conjugated π-electron chromophores and molecular scaffolds for all-carbon networks and carbon-rich nanomaterials , 1995 .

[46]  Seth R. Marder,et al.  Electric Field Modulated Nonlinear Optical Properties of Donor-Acceptor Polyenes: Sum-Over-States Investigation of the Relationship between Molecular Polarizabilities (.alpha., .beta., and .gamma.) and Bond Length Alternation , 1994 .

[47]  Frank W. Wise,et al.  Femtosecond measurement of nonlinear absorption and refraction in CdS, ZnSe, and ZnS , 1994 .

[48]  D. Terrell,et al.  Amino derivatives of symmetric 1,3,5-triphenylbenzene. Nature of the polar singlet excited state , 1993 .

[49]  J. Brédas,et al.  Donor-acceptor diphenylacetylenes : geometric structure, electronic structure, and second-order nonlinear optical properties , 1993 .

[50]  D. F. Duxbury.  The photochemistry and photophysics of triphenylmethane dyes in solid and liquid media , 1993 .

[51]  W. Edwards,et al.  Symmetry-breaking solvent effects on the electronic structure and spectra of a series of triphenylmethane dyes , 1992 .

[52]  P. G. Jones,et al.  Über eine Metathesereaktion von Tetrathiafulvalen (TTF) , 1991 .

[53]  Peter G. Jones,et al.  On a Metathesis Reaction of Tetrathiafulvalene (TTF) , 1991 .

[54]  P. G. Jones,et al.  Neue planare π-Systeme, II1) Zur Darstellung und Struktur von Tetrakis(phenylethinyl)ethen , 1991 .

[55]  H. Hopf,et al.  Neue planare π-Systeme , 1990 .

[56]  M. Kreutzer,et al.  Novel Planar π‐Systems , 1990 .

[57]  E. W. Stryland,et al.  Sensitive Measurement of Optical Nonlinearities Using a Single Beam Special 30th Anniversary Feature , 1990 .

[58]  L. F. Cooley,et al.  Determination of exciton hopping rates in ruthenium(II) tris(bipyridine) complexes by picosecond polarized absorption spectroscopy , 1990 .

[59]  P. Suppan.  Invited review solvatochromic shifts: The influence of the medium on the energy of electronic states , 1990 .

[60]  R. Wortmann,et al.  Excited state dipole moments and polarizabilities of centrosymmetric and dimeric molecules. I. Model study of a bichromophoric molecule , 1988 .

[61]  A. Fatiadi.  Addition and Cycloaddition Reactions of Tetracyanoethylene (TCNE) in Organic Chemistry , 1987 .

[62]  A. Fatiadi.  New Applications of Tetracyanoethylene in Organic Chemistry , 1986 .

[63]  .beta.-Hydroxydecanoyl thioester dehydrase. Complete characterization of the fate of the "suicide" substrate 3-decynoyl-NAC , 1986 .

[64]  M. Barfield,et al.  Carbon‐13 NMR studies of olefins having nitrile and methoxycarbonyl substituents. Additivity relationships , 1985 .

[65]  B. P. Sullivan,et al.  Solvent dependence of metal-to-ligand charge-transfer transitions. Evidence for initial electron localization in MLCT excited states of 2,2'-bipyridine complexes of ruthenium(II) and osmium(II) , 1984 .

[66]  Z. Rappoport,et al.  The kBr/kCl element effect for nucleophilic vinylic substitution of the highly reactive tricyanovinyl-X system by substituted anilines , 1984 .

[67]  H. K. Hall,et al.  Reduction potentials of olefinic electron acceptor monomers , 1983 .

[68]  A. Fletcher,et al.  Fluorescence quantum yields of some rhodamine dyes , 1982 .

[69]  F. Texier-Boullet,et al.  Knoevenagel condensation catalysed by aluminium oxide. , 1982 .

[70]  H. Hauptmann.  Diäthinylcarbene und 2,4-pentadiinylidene , 1976 .

[71]  L. Ukhin,et al.  Reaction of copper acetylides with tetracyanoquinodimethane and tetracyanoethylene , 1969 .

[72]  H. Taniguchi,et al.  Synthesis and properties of tetrakis(phenylethynyl)ethylene , 1969 .

[73]  Sidney I. Miller,et al.  Syntheses with diacetylenic ketones: 5-Membered rings by anti-michael addition , 1968 .

[74]  D. Dyrssen,et al.  Unsaturated Hydrogen-Free Halogeno Cyano Compounds. III. Preparation and Properties of Halogenocyanoethylenes. , 1963 .

[75]  A. S. Hay.  Oxidative Coupling of Acetylenes. II1 , 1962 .

[76]  E. Condon,et al.  Nuclear Motions Associated with Electron Transitions in Diatomic Molecules , 1928 .