Thienopyrrolo[3,2,1-]carbazoles: Building Blocks for Functional Organic Materials.

The facile preparation of three regioisomeric thienopyrrolo[3,2,1-]carbazoles applying a convenient C-H activation approach is presented. The incorporation of thiophene into the triarylamine framework significantly impacted the molecular properties in comparison to the analogous indolo[3,2,1-]carbazole scaffold. Dependent on the exact substitution pattern, the absorption onsets of the new materials are shifted toward slightly higher wavelengths compared to the analogous indolo[3,2,1-]carbazole, whereas the emission maxima of the sulfur derivatives is shifted from 375 to 410 nm.

The phase transitions of 4-aminopyridine-based indolocarbazoles: twinning, local- and pseudo-symmetry.

The phase transitions and polymorphism of three 4-aminopyridine-based indolocarbazole analogues are analyzed with respect to symmetry relationships and twinning. Seven polymorphs were structurally characterized using single-crystal diffraction. 5NICz (the indolo[3,2,1-jk]carbazole derivative with the C atom in the 5-position replaced by N) crystallizes as a P2/a high-temperature (270 K) polymorph and as a Pca2 low-temperature (150 K) polymorph.

Azaindolo[3,2,1-jk]carbazoles: New Building Blocks for Functional Organic Materials.

The preparation and characterization of 12 azaindolo[3,2,1-jk]carbazoles is presented. Ring-closing C-H activation allowed for the convenient preparation of six singly and six doubly nitrogen-substituted indolo[3,2,1-jk]carbazole derivatives in which ten of the materials have not been described in the literature before. The detailed photophysical and electrochemical characterization of the developed materials revealed a significant impact of the incorporation of pyridine-like nitrogen into the fully planar indolo[3,2,1-jk]carbazole backbone.

Controlling excimer formation in indolo[3,2,1-]carbazole/9-carbazole based host materials for RGB PhOLEDs.

Three novel materials (, and ), based on the indolo[3,2,1-]carbazole and 9-carbazole building blocks, with high triplet energies ( > 2.80 eV) and good thermal stability ( > 101 °C) were synthesized, characterized and applied as host materials in PhOLED devices. In course of the preparation of the materials, an improved protocol for the synthesis of the indolo[3,2,1-]carbazole moiety has been developed.

A novel selenoalkenyl-isoxazole based donor-acceptor nonlinear optical material.

The structure property relationships of untwinned enantiomorphic -(methylseleno)alkenyl-substituted phenyl-isoxazole and its isostructural triazole congener both crystallizing in the 222 space group were investigated with respect to UV/vis absorption, thermal behaviour, and second harmonic generation ability. Differential scanning calorimetry revealed a significantly higher melting point of the novel isoxazole compound compared to the triazole derivative and therefore a broader thermal application window. The SHG efficiency of the isoxazole derivative is approximately two thirds the value of the triazole compound and approximately 27 times higher than potassium dihydrogen phosphate.

Charge-transfer states in triazole linked donor-acceptor materials: strong effects of chemical modification and solvation.

A series of 1,2,3-triazole linked donor-acceptor chromophores are prepared by Click Chemistry from ene-yne starting materials. The effects of three distinct chemical variations are investigated: enhancing the acceptor strength through oxidation of the sulphur atom, alteration of the double bond configuration, and variation of the triazole substitution pattern. A detailed photophysical characterization shows that these alterations have a negligible effect on the absorption while dramatically altering the emission wavelengths.

Structure-Property Relationships in Click-Derived Donor-Triazole-Acceptor Materials.

To shed light on intramolecular charge-transfer phenomena in 1,2,3-triazole-linked materials, a series of 1,2,3-triazole-linked push-pull chromophores were prepared and studied experimentally and computationally. Investigated modifications include variation of donor and/or acceptor strength and linker moiety as well as regioisomers. Photophysical characterization of intramolecular charge-transfer features revealed ambipolar behavior of the triazole linker, depending on the substitution position.

Crystal chemistry of trialkylsilyl-capped (3Z)-4-(methylthio)-3-penten-1-yne: polymorphism, twinning and ambiguity of order-disorder descriptions.

The crystallization behavior of trimethylsilyl-capped (3Z)-4-(methylthio)-3-penten-1-yne (1-TMS) and the triisopropylsilyl and tert-butyldimethylsilyl analogues (1-TIPS) and (1-TBDMS) was investigated. (1-TMS) crystallizes in the Sohncke space group P222 with Z' = 1. (1-TIPS) exists as two polymorphs, both crystallizing in P\overline 1 with Z' = 2 independent molecules.

Crystal chemistry of layered structures formed by linear rigid silyl-capped molecules.

The crystallization behavior of methylthio- or methylsulfonyl-containing spacer extended Z,Z-bis-ene-yne molecules capped with trimethylsilyl groups obtained by (tandem) thiophene ring fragmentation and of two non-spacer extended analogs were investigated. The rigid and linear molecules generally crystallized in layers whereby the flexibility of the layer interfaces formed by the silyl groups leads to a remarkably rich crystal chemistry. The molecules with benzene and thiophene spacers both crystallized with C2/c symmetry and can be considered as merotypes.

Isotypic crystal structures of 2,6-di-bromo-N,N-bis-(4-nitro-phen-yl)aniline and 2,6-di-chloro-N,N-bis-(4-nitro-phen-yl)aniline.

In the mol-ecules of the two isotypic title compounds, C18H11Br2N3O4 (I) and C18H11Cl2N3O4 (II), the tri-phenyl-amine N atoms show no sign of pyramidalization, with marginal displacements of the N atoms from the mean plane of the three connecting C atoms: 0.0058 (13) Å for the Br compound (I) and 0.0074 (9) Å for the Cl compound (II).

9-(4-Bromo-phen-yl)-9H-carbazole.

In the title mol-ecule, C18H12BrN, the 4-bromo-phenyl ring is inclined to the mean plane of the carbazole moiety (r.m.s.

1-Nitro-9H-carbazole.

In the title mol-ecule, C12H8N2O2, the nitro group is tilted slightly with respect to the carbazole moiety [angle between the least-squares planes = 4.43 (9)°]. In the crystal, the mol-ecules are connected via pairs of N-H⋯O hydrogen bonds into dimers with -1 symmetry.

Solvatomorphism of 9,9'-[1,3,4-thiadiazole-2,5-diylbis(2,3-thiophendiyl-4,1-phenylene)]bis[9H-carbazole]: isostructurality, modularity and order-disorder theory.

During a systematic investigation of the crystallization behaviour of 9,9'-[1,3,4-thiadiazole-2,5-diylbis(2,3-thiophendiyl-4,1-phenylene)]bis[9H-carbazole] (I), six single crystalline solvates were obtained and characterized by X-ray diffraction at 100 K. The structure of the hemi-2-butanone (MEK) solvate contains two crystallographically independent molecules of (I) related by pseudo-inversion symmetry. The structure is polytypic and composed of non-polar (I) layers and polar solvent layers.