- Structural distortions in diiodine-substituted unsaturated hydrocarbons
-
1,10-Diiodophenanthrene, prepared for the first time by reacting I2 with dilithiophenanthrene, has a twist angle ω(I ··· C-C ··· I) = 63°between the two iodine centers and a distance d(I···I) = 3.61 A, which amounts to only 84% of the sum of van der Waals radii, 2r(I)(vdW) = 2 x 2.15 = 4.30 A. Based on an extensive literature search for distortions of carbon skeletons by repulsion between overlapping iodine substituents, the low-temperature structures of 2,2'-diiodobiphenyl (ω = 85°, d(I···I) = 4.35 A, 101% of 2r(I)(vdW)) and 1,8-diiodonaphthalene (ω = 2°to 17°, d(I···I) = 3.513.54 A, 82% of 2r(I)(vdW)) have also been determined. Density functional B3LYP calculations with 6-31G basis sets and 31G effective pseudopotentials for iodine provide information on an unexpectedly balanced charge distribution, leading to estimates of about 30 kJ mol-1 for the I/I repulsion and of about 10 kJ mol-1 for the reduced π delocalization in the extremely twisted skeleton of 1,10-diiodophenanthrene.
- Bock, Hans,Sievert, Mark,Havlas, Zdenek
-
-
Read Online
- Synthesis and Crystal Structure of Dimorphic Dibenzo[cde,opq]rubicene
-
Dibenzo[cde,opq]rubicene has been synthesized by an eight-step reaction sequence including an iron-mediated [2+2+1] cycloaddition and a flash vacuum pyrolysis as key steps. Two crystal modifications of the S-shaped, planar polycyclic aromatic hydrocarbon have been obtained and characterized by X-ray diffractometry.
- Suresh, Joghee R.,Whitener, Glenn,Theumer, Gabriele,Br?cher, Dirk J.,Bauer, Ingmar,Massa, Werner,Kn?lker, Hans-Joachim
-
-
Read Online
- Synthesis and characterization of bis- N -2-Aryl Triazole as a fluorophore
-
Naphthalene-bridged bis-triazole (NBT) complexes were prepared and characterized for investigation of their photophysical properties. Unlike our previously reported N-2-aryl triazoles, which gave strong emissions through the planar intramolecular charge transfer mechanism (coplanar conformation), this newly developed NBT adopted a noncoplanar conformation between triazole and naphthalene, achieving fluorescence through twisted intramolecular charge transfer.
- Zhang, Yanwei,Ye, Xiaohan,Petersen, Jeffery. L.,Li, Minyong,Shi, Xiaodong
-
-
Read Online
- Facile synthesis of 1,8-naphthalimides in palladium-catalysed aminocarbonylation of 1,8-diiodo-naphthalene
-
1,8-Diiodo-naphthalene was aminocarbonylated with various primary and secondary amines in the presence of palladium(0) complexes formed in situ from palladium(II) acetate and triphenylphosphine. In the case of primary amines, depending on the amine to substrate ratio, two types of products have been obtained in highly chemoselective reaction: dicarboxamides and N-substituted imides have been formed at high and low amine to substrate ratio, respectively. The reaction tolerates the ester functionality, so that amino acid esters could serve as N-nucleophiles and in this way, naphthalimides possessing stereogenic centre in the N-substituent could be synthesised.
- Takács, Attila,ács, Péter,Kollár, László
-
-
Read Online
- Saturated deep-blue emitter based on a spiro[benzoanthracene-fluorene]-linked phenanthrene derivative for non-doped organic light-emitting diodes
-
A spiro[benzoanthracene-fluorene] derivative containing a phenanthrene moiety, 2′,3-di(phenanthren-9-yl)spiro[benzo[de]anthracene-7,9′-fluorene] (DPSBAF), was prepared by a Suzuki coupling reaction. The photophysical and photochemical properties were investigated systematically. A non-doped organic light-emitting diode using DPSBAF as the emitter achieved a luminance efficiency of 2.18 cd A-1 with Commission Internationale de l'clairage 1931 chromaticity coordinates of (0.15, 0.09). The synthesized spiro[benzoanthracene-fluorene] derivative with a high thermal stability, a glass transition temperature of 210 °C and a decomposition temperature of 410 °C, shows potential for application in non-doped saturated deep-blue organic light-emitting diodes. This journal is
- Liang, Houjie,Wang, Xinxin,Zhang, Xingye,Liu, Zhiyang,Ge, Ziyi,Ouyang, Xinhua,Wang, Suidong
-
-
Read Online
- Intramolecular [2 + 2] Photodimerization Achieved in the Solid State via Coordination-Driven Self-Assembly
-
(Figure Presented) An intramolecular [2 + 2] photocycloaddition is achieved in the organic solid state via self-assembly of Ag(I) ions and an endo-ditopic bipyridine. The cations aide to organize carbon-carbon double (C=C) bonds attached to the bipyridine for the cycloaddition reaction. The C=C bonds react regioselectively and quantitatively to afford a photoproduct with edge-sharing four-, five-, and six-membered rings. Our study demonstrates the first use of a metal-organic template to direct an intramolecular [2 + 2] photodimerization in the organic solid state.
- Laird, Rebecca C.,Sinnwell, Michael A.,Nguyen, Nam P.,Swenson, Dale C.,Mariappan, S. V. Santhana,MacGillivray, Leonard R.
-
-
Read Online
- Peri interaction between selenium atoms in dinaphtho[1,8-b,c]-1,5-diselenocin and 1,8-bis(methylseleno)naphthalene
-
A new symmetrical diselno peri-bridged naphthalene, dinaphtho[1,8-b,c]-1,5-diselenocin (1), and 1,8-bis(methylseleno)naphthalene (2) have been synthesized. The cyclic voltammogram of 1 and 2 showed one reversible oxidation peak with remarkably low oxidation potential. Selenide 1 in CHCl3 under air and scattered light undergoes oxidation to give the corresponding Se-oxide 11. The peri selenium-selenium interaction of 1 and 2 was found in electrochemical oxidation, in concentrated sulfuric acid, and in EI mass spectrum.
- Fujihara,Yabe,Chiu,Furukawa
-
-
Read Online
- Mixed-Valent Molecular Triple Deckers
-
Two phenothiazine (PTZ) moieties were connected via naphthalene spacers to a central arene to result in stacked PTZ-arene-PTZ structure elements. Benzene and tetramethoxybenzene units served as central arenes mediating electronic communication between the two PTZ units. Based on cyclic voltammetry, UV/Vis-NIR absorption, EPR spectroscopy, and computational studies, the one-electron oxidized forms of the resulting compounds behave as class II organic mixed-valence species in which the unpaired electron is partially delocalized over both PTZ units. The barrier for intramolecular electron transfer depends on the nature of the central arene sandwiched between the two PTZ moieties. These are the first examples of rigid organic mixed-valent triple-decker compounds with possible electron-transfer pathways directly across a stacked structure, and they illustrate the potential of oligo-naphthalene building blocks for long-range electron transfer and a future molecular electronics technology.
- Schmidt, Hauke C.,Guo, Xingwei,Richard, Pascal U.,Neuburger, Markus,Palivan, Cornelia G.,Wenger, Oliver S.
-
supporting information
p. 11688 - 11691
(2018/09/10)
-
- Transition-Metal-Free Decarboxylative Iodination: New Routes for Decarboxylative Oxidative Cross-Couplings
-
Constructing products of high synthetic value from inexpensive and abundant starting materials is of great importance. Aryl iodides are essential building blocks for the synthesis of functional molecules, and efficient methods for their synthesis from chemical feedstocks are highly sought after. Here we report a low-cost decarboxylative iodination that occurs simply from readily available benzoic acids and I2. The reaction is scalable and the scope and robustness of the reaction is thoroughly examined. Mechanistic studies suggest that this reaction does not proceed via a radical mechanism, which is in contrast to classical Hunsdiecker-type decarboxylative halogenations. In addition, DFT studies allow comparisons to be made between our procedure and current transition-metal-catalyzed decarboxylations. The utility of this procedure is demonstrated in its application to oxidative cross-couplings of aromatics via decarboxylative/C-H or double decarboxylative activations that use I2 as the terminal oxidant. This strategy allows the preparation of biaryls previously inaccessible via decarboxylative methods and holds other advantages over existing decarboxylative oxidative couplings, as stoichiometric transition metals are avoided.
- Perry, Gregory J. P.,Quibell, Jacob M.,Panigrahi, Adyasha,Larrosa, Igor
-
supporting information
p. 11527 - 11536
(2017/08/30)
-
- A robust microfluidic device for the synthesis and crystal growth of organometallic polymers with highly organized structures
-
A simple and robust microfluidic device was developed to synthesize organometallic polymers with highly organized structures. The device is compatible with organic solvents. Reactants are loaded into pairs of reservoirs connected by a 15 cm long microchannel prefilled with solvents, thus allowing long-term counter diffusion for self-assembly of organometallic polymers. The process can be monitored, and the resulting crystalline polymers are harvested without damage. The device was used to synthesize three insoluble silver acetylides as single crystals of X-ray diffraction quality. Importantly, for the first time, the single-crystal structure of silver phenylacetylide was determined. The reported approach may have wide applications, such as crystallization of membrane proteins, synthesis and crystal growth of organic, inorganic, and polymeric coordination compounds, whose single crystals cannot be obtained using traditional methods.
- Liu, Xiao,Yi, Qiaolian,Han, Yongzhen,Liang, Zhenning,Shen, Chaohua,Zhou, Zhengyang,Sun, Junliang,Li, Yizhi,Du, Wenbin,Cao, Rui
-
supporting information
p. 1846 - 1850
(2015/02/19)
-
- Screw imidazolecarboxylic compd.
-
PROBLEM TO BE SOLVED: To provide a bisimidazole compound exhibiting excellent photochromic characteristics of high color optical density and rapid speed of fading.SOLUTION: The bisimidazole compound is represented by general formula (I) (wherein, Ar, Ar, Ar, R, R, Rand Rare each a specific group; and a, b, c and d are each an integer of 0-3).
- -
-
Paragraph 0058-0060
(2017/01/02)
-
- Mechanistic studies of hoveyda-grubbs metathesis catalysts bearing S-, Br-, I-, and N-coordinating naphthalene ligands
-
Derivatives of the Hoveyda-Grubbs complex bearing S-, Br-, I-, and N-coordinating naphthalene ligands were synthesized and characterized with NMR and X-ray studies. Depending on the arrangement of the coordinating sites on the naphthalene core, the isomeric catalysts differ in activity in model metathesis reactions. In particular, complexes with the Rui£CH bond adjacent to the second aromatic ring of the ligand suffer from difficulties experienced on their preparation and initiation. The behavior most probably derives from steric hindrance around the double bond and repulsive intraligand interactions, which result in abnormal chemical shifts of benzylidene protons observed with 1HNMR. Furthermore EXSY studies revealed that the halogen-chelated ruthenium complexes display an equilibrium, in which major cis-Cl2 structures are accompanied with small amounts of isomeric forms. In general, contents of the minor forms, measured at 80°C, correlate with the observed activity trends of the catalysts, although some exceptions complicate the mechanistic picture. We assume that for the family of halogen-chelated metathesis catalysts the initiation mechanism starts with the cis-Cl 2a?trans-Cl2 isomerization, although further steps may become rate-limiting for selected systems. Isomerization first: A family of halogen-chelated Hoveyda-Grubbs complexes displays a cis-Cl2a?trans-Cl2 equilibrium in solution. Relative contents of the minor trans forms go along with the activity of the metathesis catalysts, suggesting its participation in the initiation mechanism (see figure). A unique effect of the naphthalene ligands enables control of the activity over a broad range, from moderately achieve to dormant, and was manifested in 1HNMR for complexes with repulsive H×××H intraligand interactions (Mes=Mesityl).
- Grudzien, Krzysztof,Zukowska, Karolina,Malinska, Maura,Wozniak, Krzysztof,Barbasiewicz, Michal
-
supporting information
p. 2819 - 2828
(2014/03/21)
-
- Efficient tuning of electroluminescence from sky-blue to deep-blue by changing the constitution of spirobenzofluorene derivatives
-
Two novel benzimidazole-attached spiro[benzofluorene] derivatives, 2,2′-(spiro[benzo[c]fluorine-7,9′-fluorene]-5,9-diylbis(4, 1-phenylene))bis(1-phenyl-1H-benzo[d]imidazole) and 2,2′-(spiro[benzo-[de] anthracene-7,9′-fluorene]-2′,3-diylbis(4,1-phenylene)) bis(1-phenyl-1H-benzo[d]imidazole), were prepared by a Suzuki coupling reaction. Their photophysical and photochemical properties were studied systemically. The fluorescent organic light-emitting diodes were fabricated by using them as the emitters, all of them showed strong blue emission. Interestingly, from the benzoanthracene derived compound a high color purity was found with Commission de L'Eclairage 1931 chromaticity coordinates of (0.15, 0.10) and an efficiency of 1.96 cd/A. To the best of our knowledge, this is the first time to obtain a deep-blue emission with spiro[benzofluorene] derivative in a nondoped device.
- Liang, Houjie,Wang, Xinxin,Zhang, Xingye,Ge, Ziyi,Ouyang, Xinhua,Wang, Suidong
-
-
- Through-space control of the persistence of photogenerated o-quinonoid intermediates in naphthalenes containing cofacially oriented chromenes and arenes
-
Remarkable modulation of the persistence of the photogenerated colored o-quinonoid intermediates via a through-space interaction has been demonstrated in chromenes 1-4 based on 1,8-diarylnaphthalenes. Polar/π interaction is shown to stabilize the closed form of 4 to such an extent that photoinduced coloration is virtually invisible, while the same stabilization in the opened form of 2 permits ready coloration with a long-lived o-quinonoid intermediate.
- Moorthy, Jarugu Narasimha,Mandal, Susovan,Parida, Keshaba Nanda
-
supporting information; scheme or table
p. 2438 - 2441
(2012/07/13)
-
- Enantioselective synthesis of (+)-estrone exploiting a hydrogen bond-promoted Diels?Alder reaction
-
Starting from Danes diene and methylcyclopentenedione, (+)-estrone is synthesized along the Quinkert?Dane route in 24% total yield. The key step is an enantioselective Diels?Alder reaction promoted by an amidinium catalyst as efficiently as by a traditional Ti-TADDOLate Lewis acid.
- Weimar, Marko,Duerner, Gerd,Bats, Jan W.,Goebel, Michael W.
-
supporting information; experimental part
p. 2718 - 2721
(2010/07/17)
-
- Novel foldamer structural architecture from cofacial aromatic building blocks
-
This communication demonstrates the utility of peri-substituted 1,8-diphenylnaphthalene as an effective building block for the construction of novel conformationally ordered synthetic oligomers displaying cofacial structural features.
- Prabhakaran, Panchami,Puranik, Vedavati. G.,Chandran, Jima N.,Rajamohanan, Pattuparampil R.,Hofmann, Hans-Joerg,Sanjayan, Gangadhar J.
-
supporting information; scheme or table
p. 3446 - 3448
(2009/12/26)
-
- Electrochemical Property and Formation of the Cation Radical and Dication of Dinaphtho-1,5-dithiocin
-
A new symmetrical dithio peri-bridged naphthalene, dinaphtho-1,5-dithiocin (1) has been synthesized.The cyclic voltammogram of 1 showed one reversible oxidation peak.ESR spectrum of the concd H2SO4 solution of 1 showed the formation of the cation radical.The formation of the dication of 1 was observed in the reaction of the corresponding monosulfoxide with concd D2SO4 by both high-field 1H and 13C NMR spectroscopy.
- Fujihara, Hisashi,Chiu, Jer-Jye,Furukawa, Naomichi
-
p. 2217 - 2220
(2007/10/02)
-
- AN EFFICIENT SYNTHESIS OF AROMATIC IODIDES FROM AROMATIC CARBOXYLIC ACIDS
-
Aromatic iodides are prepared from readily available carboxylic acids via oxidative decarboxylation with iodosobenzene diacetate/iodine in carbon tetrachloride.
- Singh, Rina,Just, George
-
p. 1327 - 1330
(2007/10/02)
-