D-A-D Compounds Combining Dithienopyrrole Donors and Acceptors of Increasing Electron-Withdrawing Capability: Synthesis, Spectroscopy, Electropolymerization, and Electrochromism.

Five compounds consisting of the same donor unit (dithieno[3,2-:2',3'-]pyrrole, ), the same π-linker (2,5-thienylene), and different acceptors of increasing electron-withdrawing ability (1,3,4-thiadiazole (), benzo[][1,2,5]thiadiazole (), 2,5-dihydropyrrolo[3,4-]pyrrole-1,4-dione (), 1,2,4,5-tetrazine (), and benzo[][3,8]phenanthroline-1,3,6,8(2,7)-tetraone ()) were synthesized. , , and turned out to be interesting luminophores emitting either yellow ( or near-infrared ( and ) radiation in dichloromethane solutions. The emission bands were increasingly bathochromically shifted with increasing solvent polarity.

9,10-Anthraquinones Disubstituted with Linear Alkoxy Groups: Spectroscopy, Electrochemistry, and Peculiarities of Their 2D and 3D Supramolecular Organizations.

Spectroscopic, electrochemical, and structural properties of 2,6-dialkoxy-9,10-anthraquinones (Anth-OC, = 4, 6, 8, 10, and 12) of increasing alkoxy substituents length were investigated. UV-vis spectroscopy showed a substitution-induced bathochromic shift of the least energetic band from 325 nm in the case of unsubstituted anthraquinone to ca. 350 nm for the studied derivatives.

Self-Assembly Properties of Solution Processable, Electroactive Alkoxy, and Alkylthienylene Derivatives of Fused Benzoacridines: A Scanning Tunneling Microscopy Study.

Self-organization in mono- and bilayers on HOPG of two groups of benz[5,6]acridino[2,1,9,8-]acridine derivatives, namely, 8,16-dialkoxybenzo[]benz[5,6]acridino[2,1,9,8-]acridines with an increasing alkoxy substituent length and 8,16-bis(3- or 4- or 5-octylthiophen-2-yl)benzo[]benz[5,6]acridino[2,1,9,8-]acridines, i.e., three positional isomers of the same benzoacridine, is investigated by scanning tunneling microscopy.

High-Spin Polymers: Ferromagnetic Coupling of S = 1 Hexaazacyclophane Units up to a Pure S = 2 Polycyclophane.

Triarylamines oxidized to radical cations can be used as stable spins sources for the design of high-spin compounds. Here, we present the synthesis of the polyarylamine-containing hexaazacyclophanes linked via meta-terphenyl bridges. Spins, created after oxidation of the polymer, can be coupled magnetically in cyclophane moieties via meta-phenyl and along the polymer chain via meta-terphenyl units.

Low and High Molecular Mass Dithienopyrrole-Naphthalene Bisimide Donor-Acceptor Compounds: Synthesis, Electrochemical and Spectroelectrochemical Behaviour.

Two low molecular weight electroactive donor-acceptor-donor (DAD)-type molecules are reported, namely naphthalene bisimide (NBI) symmetrically core-functionalized with dithienopyrrole (NBI-(DTP) ) and an asymmetric core-functionalized naphthalene bisimide with dithienopyrrole (DTP) substituent on one side and 2-ethylhexylamine on the other side (NBI-DTP-NHEtHex). Both compounds are characterized by low optical bandgaps (1.52 and 1.

Star-Shaped Conjugated Molecules with Oxa- or Thiadiazole Bithiophene Side Arms.

Star-shaped conjugated molecules, consisting of a benzene central unit symmetrically trisubstituted with either oxa- or thiadiazole bithiophene groups, were synthesized as promising molecules and building blocks for application in (opto)electronics and electrochromic devices. Their optical (Eg (opt)) as well as electrochemical (Eg (electro)) band gaps depended on the type of the side arm and the number of solubilizing alkyl substituents. Oxadiazole derivatives showed Eg (opt) slightly below 3 eV and by 0.

Soluble Flavanthrone Derivatives: Synthesis, Characterization, and Application to Organic Light-Emitting Diodes.

Simple modification of benzo[h]benz[5,6]acridino[2,1,9,8-klmna]acridine-8,16-dione, an old and almost-forgotten vat dye, by reduction of its carbonyl groups and subsequent O-alkylation, yields solution-processable, electroactive, conjugated compounds of the periazaacene type, suitable for the use in organic electronics. Their electrochemically determined ionization potential and electron affinity of about 5.2 and -3.

Formation of High-Spin States (S = 3/2 and 2) in Linear Oligo- and Polyarylamines.

This article describes the study of a linear trimer and three polyarylamines PB1-3 containing a 3,4'-biphenyl ferromagnetic coupler. The synthesis of the model compound (trimer) and the polymers has been presented. The formation of radical cations was studied using electrochemical and optical (UV-vis) methods.

Raman changes induced by electrochemical oxidation of poly(triarylamine)s: toward a relationship between molecular structure modifications and charge generation.

Linear, alternating polymers of aromatic amines (p-phenylenediamine, bis(p-aminophenyl)amine, and diaminocarbazole) and either m-phenylene or 3,5-pyridine have been synthesized and characterized by electrochemical and spectroscopic means. The presence of radical cations in their electrochemically oxidized forms is manifested by new bands in the UV-vis-NIR spectra whose appearance can be correlated with reversible redox couples registered in the corresponding cyclic voltammograms at approximately the same potentials as well as with pronounced evolutions of their resonance Raman spectra. Detailed analysis of the Raman data gives information about the locations and the distribution of radical cations and spinless dication in the macromolecule.

Indanthrone dye revisited after sixty years.

Indanthrone, an old, insoluble dye can be converted into a solution processable, self-assembling and electroluminescent organic semiconductor, namely tetraoctyloxydinaptho[2,3-a:2',3'-h]phenazine (P-C8), in a simple one-pot process consisting of the reduction of the carbonyl group by sodium dithionite followed by the substitution with solubility inducing groups under phase transfer catalysis conditions.

(Photo)physical Properties of New Molecular Glasses End-Capped with Thiophene Rings Composed of Diimide and Imine Units.

New symmetrical arylene bisimide derivatives formed by using electron-donating-electron-accepting systems were synthesized. They consist of a phthalic diimide or naphthalenediimide core and imine linkages and are end-capped with thiophene, bithiophene, and (ethylenedioxy)thiophene units. Moreover, polymers were obtained from a new diamine, ,'-bis(5-aminonaphthalenyl)naphthalene-1,4,5,8-dicarboximide and 2,5-thiophenedicarboxaldehyde or 2,2'-bithiophene-5,5'-dicarboxaldehyde.

Ferromagnetic Spin Coupling through the 3,4'-Biphenyl Moiety in Arylamine Oligomers-Experimental and Computational Study.

This report describes the study of a dimer d and a linear trimer t of amminium radical cations coupled by 3,4'-biphenyl spin coupling units. The synthesis of the parent diamine and triamine and their optical and electrochemical properties obtained by UV-visible and cyclic voltammetry are presented. The chemical doping of the parent diamine d and triamine t was performed quantitatively to obtain samples containing the corresponding dimer d and trimer t in almost pure high-spin states as evidenced by pulsed EPR nutation spectroscopy.

Vibrational dynamics in dendridic oligoarylamines by Raman spectroscopy and incoherent inelastic neutron scattering.

Vibrational dynamics in triarylamine dendrimers was studied in a complementary way by Raman and infrared (IR) spectroscopies and incoherent inelastic neutron scattering (IINS). Three molecules were investigated, namely, unsubstituted triarylamine dendrimer of the first generation and two dendrimers of the first and second generation, substituted in the crown with butyl groups. To facilitate the assignment of the observed IR and Raman modes as well as the IINS peaks, vibrational models, based on the general valence force field method (GVFF), were calculated for all three compounds studied.

Optical properties of unsymmetrical azomethines with one imine bonds.

We have explored the photoluminescence (PL) and electronic properties, that is, orbital energies and resulting energy gap calculated theoretically by density functional theory (DFT) of four unsymmetrical (UAz1-UAz4) azomethines. All of the investigated compounds exhibited mesomorphic behavior. The photoluminescence studies have shown that molecular structure of the imines influenced both the PL properties and HOMO-LUMO levels of azomethines.