scholarly journals Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

2021 ◽  
Vol 17 ◽  
pp. 11-21
Author(s):  
Daria I Tonkoglazova ◽  
Anna V Gulevskaya ◽  
Konstantin A Chistyakov ◽  
Olga I Askalepova
Keyword(s):  
Crystal Structures ◽  
Fluorescence Spectra ◽  
Absorption And Fluorescence Spectra ◽  
X Ray ◽  
Structures And Properties ◽  
Synthetic Sequence

Novel carbazole-based [6]helicenes fused with an azine ring (pyridine, pyrazine or quinoxaline) have been prepared through a five-step synthetic sequence in good overall yields. Commercially available 2,3-dihaloazines were used as starting materials. To discern the effect of merging an azine moiety within a helical skeleton, the X-ray structures, UV–vis absorption and fluorescence spectra of the helicenes were investigated and compared to that of the parent carbazole-based [6]helicene (7H-phenanthro[3,4-c]carbazole).

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

Synthesis ◽  
2021 ◽  
Author(s):  
Yusuke Matsuo ◽  
Atsuhiro Osuka ◽  
Takayuki Tanaka
Keyword(s):  
Dft Calculations ◽  
Diffraction Analysis ◽  
Strain Energy ◽  
Fluorescence Spectra ◽  
Reaction Path ◽  
Absorption And Fluorescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rigid Structure ◽  
Type Compound

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.

Pd(II) and Pt(II) Complexes of 1,2-Bis(pyridin-2-yl)ethane-N,N'

1994 ◽  
Vol 49 (6) ◽  
pp. 844-848 ◽  
Author(s):  
A. McFarlane ◽  
J. R. Lusty ◽  
J. J. Fiol ◽  
A. Terrón ◽  
E. Molins ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Spectroscopic Data ◽  
Low Energy ◽  
X Ray ◽  
H Nmr ◽  
Direct Bond ◽  
Structures And Properties ◽  
C Nmr

X-ray crystal structures and properties of the two Pd(II) and Pt(II) complexes [bpeH2][PdCl4] and [Pt(bpe)Cl2], [bpe = 1,2-bis(pyridin-2-yl)ethane] are described and correlated with the IR and 1H NMR/13C NMR spectroscopic data. In the case of the Pt(II) complex, the 1,2-bis(pyridin-2-yl)ethane is bound to the metal by the heterocycle nitrogen atoms but no direct bond is found in the case of the Pd(II) complex. The ligand exhibits low energy geometries in both compounds: the cis-conformation in the Pt(II) complex, and the transconformation in the Pd(II) complex

Synthesen, Kristallstrukturen und Eigenschaften von Trisilber-und Trikalium-tri-μ-imido-cyclotriphosphat, Ag3(PO2NH)3 und K3(PO2NH)3 / Syntheses, Crystal Structures, and Properties of Trisilver and Tripotassium Tri-μ-im ido Cyclotriphosphate, Ag3(PO2NH)3 and K3(PO2NH)3

1997 ◽  
Vol 52 (2) ◽  
pp. 251-255 ◽  
Author(s):  
N. Stock ◽  
W. Schnick
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Chair Conformation ◽  
X Ray ◽  
Diffusion Controlled ◽  
Structures And Properties ◽  
Ray Methods

Abstract Coarse crystalline Ag3(PO2NH)3 (1) and K3(PO2NH)3 (2) are obtained by addition of an aqueous solution of AgNO3 to an acidified solution of Na3(PO2NH)3 · 4H2O and by diffusion controlled addition of ethanol to a solution of K3(PO2NH)3 in water, respectively. The crystal structures of 1 and 2 have been determined by single crystal X-ray methods (Ag3(PO2NH)3: P21/c; a = 1166.6(1), b = 786.4(1), c = 997.8(1) pm, β = 106.91(1)°; Z = 4. K3(PO2NH)3: R3̄; a = 1271.4(2), c = 1017.9(2) pm, Z = 6). In Ag3(PO2NH)3 the cyclic anion is markedly distorted because of interactions between Ag+ and one nitrogen atom of the anion. In K3(PO2NH)3 the trimetaphosphimate ring shows a chair conformation and two cyclic anions are connected to each other by hydrogen bonds. DTA/TG investigations show thermal decomposition above 275 and 250 °C for 1 and 2, respectively.

Synthesis, Crystal Structures and Properties of the Polychalcogenides Manganese-tris(1,2-ethanediamine)-triselenide [Mn(en)3]Se3 and Manganese-tris(1,2-ethanediamine)-monotellurodiselenide [Mn(en)3 ]TeSe2

2000 ◽  
Vol 55 (9) ◽  
pp. 871-876 ◽  
Author(s):  
Frank Wendland ◽  
Christian Näther ◽  
Wolfgang Bensch
Keyword(s):  
Thermal Analysis ◽  
Weight Loss ◽  
Differential Thermal Analysis ◽  
Crystal Structures ◽  
Elemental Selenium ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Structures And Properties ◽  
Two Samples ◽  
Solvothermal Conditions

The reaction of manganese(II)-chloride-tetrahydrate, caesium triselenide and elemental selenium or tellurium in 1,2-ethanediamine (en) under solvothermal conditions leads to the formation of two new isostructural compounds [Mn(en)3]Se3 (1) and [Mn(en)3]TeSe2 (2). The compounds crystallize in the orthorhombic space group Pbcn with the lattice parameters a = 1149.39(9), b = 1506.83(11), c = 935.96(6) pm for 1 and a = 1184.1(2), b = 1495.3(2), c = 949.8(1) pm for 2. Their crystal structures are built up of [Mn(en)3]2+ cations and Se32- or TeSe22- anions, respectively. Each cation is surrounded by six next neighbouring anions, and vice versa. Between the cations and the anions hydrogen bonding is observed. The thermal behaviour was investigated using differential thermal analysis, thermogravimetry as well as X-ray powder diffraction. Completely different properties were found. Compound 1 decomposes in two distinct endothermic steps, while compound 2 shows only one endothermic peak. The weight loss for 1 corresponds roughly to the emission of all en molecules, whereas the weight loss for 2 is significantly lower. The final products are composed of MnSe2 and elemental Se or Te, respectively, and an unknown crystalline phase which is different for the two samples

Synthesis, Crystal Structure and Spectroscopy of Dibutyl Ester-Ether Fluorescein

2011 ◽  
Vol 415-417 ◽  
pp. 1443-1446
Author(s):  
Ke Liang Zhang ◽  
Ning Sheng Zhang ◽  
Chen Tun Qu
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Fluorescence Spectra ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
Absorption And Fluorescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
3 Dimensional ◽  
Dibutyl Ester

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.

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