Scholl Reaction of an ortho-Phenylene-bridged Cyclic Pyrrole-Thiophene Hybrid Hexamer

Synthesis ◽  
2021 ◽  
Author(s):  
Yusuke Matsuo ◽  
Atsuhiro Osuka ◽  
Takayuki Tanaka

Scholl reaction of ortho-phenylene-bridged cyclic pyrrole-thiophene hybrid hexamer exclusively gave a cyclophane-type compound of [5]heterohelicenes in 45% yield. The structure was unambiguously revealed by X-ray diffraction analysis. This helicenophane-type compound showed sharp absorption and fluorescence spectra, reflecting its rigid structure. The reaction path was analyzed on the basis of DFT calculations. The reaction path was analyzed on the basis of DFT calculations, and it was found that the formation of 8 is thermodynamically favored and further oxidation is prohibited due to the increased strain energy.

2011 ◽  
Vol 415-417 ◽  
pp. 1443-1446
Author(s):  
Ke Liang Zhang ◽  
Ning Sheng Zhang ◽  
Chen Tun Qu

The title compound has been prepared from the reaction of fluorescein and 1-bromobutane in the presence of potassium carbonate. Its crystal and molecular structure is determined by single crystal X-ray diffraction. Its crystal is monoclinic space group P2(1)/n with lattice parameters: a = 8.0460(19) Å, b = 13.198(3) Å, c = 22.208(5) Å, α = 90.00º, β = 94.140(3)º, γ = 90.00º, V= 2352.1(9)Å3, Density (calculated) 1.228 mg /m3, μ(mm-1) = 0.08, absorption coefficient = 0.082m−1, F(000) 1034, Z = 4. In the crystal structure, intermolecular O-H hydrogen bands are responsible for the formation of a 3-dimensional net-work. The UV-vis absorption and fluorescence spectra of both dibutyl ester-ether fluorescein was studied.


2009 ◽  
Vol 74 (4) ◽  
pp. 389-400 ◽  
Author(s):  
Bojana Krajcinovic ◽  
Goran Kaludjerovic ◽  
Dirk Steinborn ◽  
Harry Schmidt ◽  
Christoph Wagner ◽  
...  

The reaction of K2[PdCl4] with (S,S)-(i-Pr)2eddip diester (diisopropyl (S,S)-2,2'-(1,2-ethanediyldiimino)dipropanoate) resulted in {PdCl2[(S,S)-(i- -Pr)2eddip-?2N,N']} (1) and {PdCl[(S,S)-(i-Pr)eddip-?2N,N',?O]} (2) with one hydrolyzed ester group. The compounds were characterized by spectroscopic methods and it was proved that the reaction is diastereoselective (1H- and 13C-NMR) in the case of 2 (one diastereoisomer of four possible). The structure of 2 was determined by X-ray diffraction analysis, indicating that the product is the (R,R)-N,N' configured isomer. In contrast, the reaction yielding 1 produced two of three possible diastereoisomers. DFT calculations support the formation of two diastereoisomers of 1 and of one diastereoisomer of 2.


2004 ◽  
Vol 82 (2) ◽  
pp. 285-292 ◽  
Author(s):  
Trevor W Hayton ◽  
Brian O Patrick ◽  
Peter Legzdins ◽  
W Stephen McNeil

The monomeric trinitrosyl complex, W(NO)3Cl3, can be prepared by the treatment of WCl6 in CH2Cl2 with NO gas, and its identity has been unambiguously confirmed by a single-crystal X-ray diffraction analysis. The complex crystallizes in the space group Pmn21 as a three-component twin (a = 10.4280(4) Å, b = 6.3289(2) Å, c = 5.6854(2) Å, Z = 2, R1 = 0.065, wR2 = 0.176). Its solid-state molecular structure consists of a tungsten centre bound to three chloride ligands and three linear nitrosyl ligands in a fac-octahedral stereochemistry. In addition, the structure contains a crystallographically imposed mirror plane. The two independent W—N linkages are 1.88(2) and 1.92(1) Å long, while the two corresponding N—O bond lengths are 1.13(2) and 1.16(2) Å. DFT calculations on fac-W(NO)3Cl3 at the B3LYP/LANL2DZ level of theory afford optimized intramolecular metrical parameters that match the X-ray crystallographically determined bond lengths and bond angles quite well. In addition, they provide a rationale for the nearly linear W-N-O linkages extant in the complex. Solutions of fac-W(NO)3Cl3 in CH2Cl2 lose ClNO under ambient conditions and deposit the well-known [W(NO)2Cl2]n polymer, and this conversion is fully reversible.Key words: nitrosyl, tungsten, structure, bonding.


Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2609-2613 ◽  
Author(s):  
Fumitoshi Kakiuchi ◽  
Akiko Izumoto ◽  
Hikaru Kondo ◽  
Takuya Kochi

Tetraarylanthracenes containing several fluoro groups were synthesized using the ruthenium-catalyzed C–O or C–F arylation with arylboronates and their structural and spectroscopic studies were conducted. The RuH2(CO)(PPh3)3-catalyzed C–O arylation of aromatic ketones was found to be effective for the introduction of aryl groups containing multiple fluoro groups. Anthracenes possessing fluorinated aryl groups were prepared in two steps from 1,4,5,8-tetramethoxyanthraquinone by C–O arylation and reduction of the carbonyl groups. A tetraphenylanthracene containing a fluorinated anthracene moiety was also prepared using C–F phenylation of octafluoroanthraquinone. Single-crystal X-ray diffraction analysis showed that the positions of fluoro groups on the tetraarylanthracenes lead to notable difference in the crystal packing structures. The larger difference between the tetraarylanthracenes was observed in the fluorescence spectra in the solid state than those in chloroform.


Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.


1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.


2008 ◽  
Vol 73 (8-9) ◽  
pp. 1205-1221 ◽  
Author(s):  
Jiří Zedník ◽  
Jan Sedláček ◽  
Jan Svoboda ◽  
Jiří Vohlídal ◽  
Dmitrij Bondarev ◽  
...  

Dinuclear rhodium(I) η2:η2-cycloocta-1,5-diene (series a) and η2:η2-norborna-2,5-diene (series b) complexes with μ-RCOO- ligands, where R is linear C21H43 (complexes 1a, 1b), CH2CMe3 (2a, 2b), 1-adamantyl (3a, 3b) and benzyl (4a, 4b), have been prepared and characterized by spectroscopic methods. Structures of complexes 2b, 3a and 4a were determined by X-ray diffraction analysis. Complexes prepared show low to moderate catalytic activity in polymerization of phenylacetylene in THF giving high-cis-transoid polymers, but they show only oligomerization activity in dichloromethane.


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