2,3-Dimeth­oxy-5,12-tetra­cenequinone

The mol­ecule of the title compound, C20H14O4, is approximately planar [maximum deviation 0.168 (2) Å]. The two meth­oxy groups are slightly twisted relative to the plane of the 5,12-tetra­cenequinone system, with twist angles of 3.3 (3) and 5.6 (2)°. All O atoms are involved in intermolecular C—H⋯O inter­actions and the mol­ecules are arranged into slipped face-to-face stacks along the b axis via π–π inter­actions with an inter­planar distance of 3.407 (2) Å

1,7-Diethyl-4,10-diisopropyl­tetra­cene

The mol­ecule of the title compound, C28H32, is located on a crystallographic inversion center. The ethyl groups are essentially coplanar with the tetra­cene ring, making a torsion angle of −0.4 (4)°. The isopropyl groups adopt an asymmetric conformation with their terminal methyl groups positioned on opposite sides of the tetra­cene plane [the Me—C—C—C torsion angles are −22.5 (4) and 100.9 (3)°]. In the crystal, the mol­ecules adopt an arrangement without significant π–π inter­actions along the stacking direction (y axis)

1,4,5,8-Tetra-n-butyl­anthracene

The mol­ecule of the title compound, C30H42, occupies a special position on an inversion center. The four butyl side chains have all-trans planar conformations, and the alkyl planes are nearly orthogonal to the anthracene plane [C—C—C—C torsion angles of 79.6 (2) and 78.2 (2)°]. The overall mol­ecule has a stair-like shape with the n-butyl groups at the 1 and 8 positions extending towards the same side of the anthracene plane. In the crystal structure, mol­ecules adopt a slipped–parallel arrangement without π–π stacking

1,4,5,8-Tetra­isopropyl­anthracene

The mol­ecules of the title compound, C26H34, possess crystallographically imposed inversion symmetry. The anthracene ring system is planar within 0.038 (1) Å. The two methyl groups in each independent isopropyl group are oriented on either side of the anthracene plane. In the crystal structure, the mol­ecules adopt a herringbone-like arrangement without π–π stacking

Medium Diradical Character, Small Hole and Electron Reorganization Energies and Ambipolar Transistors in Difluorenoheteroles

Four difluorenoheteroleshavinga centralquinoidalcore with the heteroringvaryingas furan,thiophene,its dioxidederivativeand pyrrolehave shownto be mediumcharacterdiradicals.Solid-statestructures,optical,photophysical,magnetic,and electrochemicalpropertieshave been discussedin termsof diradicalcharacter,variationof aromaticcharacterand captoda-tive effects(electronaffinity).Organicfield-effecttran-sistors(OFETs)have been prepared,showingbalancedholeand electronmobilitiesof the orderof103cm2V1s1or ambipolarchargetransportwhichisfirst inferredfrom their redoxamphoterism.Quantumchemicalcalculationsshow that the electricalbehaviorisoriginatedfrom the mediumdiradicalcharacterwhichproducessimilarreorganizationenergiesfor hole andelectrontransports.The visionof a diradicalas simulta-neouslybearingpseudo-holeand pseudo-electronde-fects might justifythe reducedvaluesof reorganizationenergiesfor both regimes.Structure-functionrelation-ships betweendiradicaland ambipolarelectricalbehav-ior are revealed.The authorsthankthe SpanishMinistryof ScienceandInnovation(projectsMINECO/FEDERPGC2018-098533-B-100,and PID2019-110305GB-I00),the Junta de Andalucíaand GeneralidadValenciana,Spain (UMA18FEDERJA057,P18-FR-4549and Prometeo/2019/076)and JSPS KAKENHIgrant (JP21K05042for S.-i.K.,JP21K04995and JP21H05489for R.K., JP21H01887and JP20K21173for M.N.).S.-i.K.gratefullyacknowledgesthe AsahiGlassFoundationforfinancialsupport.We also thankthe ResearchCentralServices(SCAI)of the Universityof Málaga,UnidaddeEspectroscopíaVibracional(Dra. Capely Dr. Zafra)andUnidadde OpticaNo-Linealy EspectroscopíaUltrarápida(Dr. Román).This work was partiallysupportedby theCooperativeResearchProgram“NetworkJoint ResearchCenterfor Materialsand Devices”(KyushuUniversity).WethankProf. ShuheiHigashibayashi(KeioUniversity)forassistancewith synthesis.Mass spectrometricdata werecollectedat HiroshimaUniversity(N-BARD:Ms. TomokoAmimoto).Theoreticalcalculationswere partlyperformedusing ResearchCenterfor ComputationalScience(R-CCS),Okazaki,Japan.F.N and Y.D. acknowledgesupportfrom“Valutazionedella Ricercadi Ateneo”(VRA)—Universityof Bologna.Y.D. acknowledgesMinisterodell’Universitàedella Ricerca(MUR)for her Ph.D. fellowship. Funding for open access charge: Universidad de Málaga / CBU

Crystal structures of 1-hydroxy-4-propyloxy-9,10-anthraquinone and its acetyl derivative

1-Hydroxy-4-propyloxy-9,10-anthraquinone, C17H14O4, (I), and its acetyl derivative, 4-acetyloxy-4-propyloxy-9,10-anthraquinone, C19H16O5, (II), were synthesized from the commercially available dye quinizarin. In both compounds, the anthraquinone frameworks are close to planarity. There is a large difference in the conformation of the propyloxy group; the molecule of (I) adopts a gauche conformation [O—C—C—C = −64.4 (2)°], although the molecule of (II) takes a trans-planar conformation (zigzag) [O—C—C—C = 176.1 (3)°]. In the molecule of (I), there is an intramolecular O—H...O hydrogen bond. In both crystals, the molecules are linked by C—H ...O hydrogen bonds. A difference in the molecular arrangements of (I) and (II) is found along the stacking directions

Anthracene-1,4,9,10-tetraone

The asymmetric unit of the title compound, C14H6O4, contains three independent molecules (A, B and C). In molecule C, there are two disordered sets of two carbonyl O atoms [occupancies = 0.643 (11) and 0.357 (11)]. All three molecules are non-planar due to repulsion between two O atoms in peri positions on the anthracene ring, showing a slight difference in deviation of the carbonyl O atoms. The intramolecular distances between the two nearest O atoms are in the range of 2.685 (10)–2.766 (10) Å. In the crystal, molecules are linked by C—H...O and π–π [centroid–centroid distances = 3.615 (2), 3.844 (2) and 3.921 (2) Å] interactions, which lead to the formation of a herringbone-like arrangement

9,10-Diiodophenanthrene

The whole molecule of the title compound, C14H8I2, is generated by crystallographic twofold symmetry. The molecule is planar [maximum deviation = 0.0323 (6) Å] with the I atoms displaced from the mean plane of the phenanthrene ring system by only 0.0254 (5) Å. In the crystal, molecules form face-to-face slipped antiparallel π–π stacking interactions along the c axis with an interplanar distance of 3.499 (7) Å