2050-75-1Relevant articles and documents
Single molecules of terrylene in di-substituted naphthalenes crystallizing in the herringbone pattern
Bia?kowska, Magda,Cha?adaj, Wojciech,Deperasińska, Irena,Drzewiecka-Antonik, Aleksandra,Koziol, Anna E.,Makarewicz, Artur,Kozankiewicz, Boles?aw
, p. 2780 - 2788 (2017)
2,3-Dichloronaphthalene (2,3-DCN) and 2,3-dibromonaphthalene (2,3-DBN) were synthesized, purified and used to grow single crystals in the form of thin plates. X-ray crystallographic studies, performed for the first time, showed that molecules in both isostructural crystals are arranged in the herringbone pattern. These crystals, lightly doped with terrylene (Tr), appeared to be very good systems for optical single-molecule studies. Fluorescence excitation spectra of single Tr molecules at 5 K in excess of the dominating purely electronic (0, 0) and intense vibronic line of ～250 cm-1 frequency had a new, “184 cm-1” line, absent in the spectrum of isolated (D2h) Tr. Quantum-chemistry calculations indicated that this new line was the fingerprint of the deformation of the Tr molecule in the crystal structure, which lowered its symmetry to C2h
Degradation of one-side fully-chlorinated 1,2,3,4-tetrachloronaphthalene over Fe-Al composite oxides and its hypothesized reaction mechanism
Liu, Yalu,Lu, Huijie,Pan, Wenxiao,Li, Qianqian,Su, Guijin,Zheng, Minghui,Gao, Lirong,Liu, Guorui,Liu, Wenbin
, p. 17577 - 17585 (2017/03/31)
The degradation of 1,2,3,4-tetrachloronaphthalene (CN-27) featuring a one-side fully-chlorinated aromatic ring, was evaluated over three of the prepared rod-like Fe-Al composite oxides (FeAl-1, FeAl-5 and FeAl-10). The results showed that their reactive activities were in the order of FeAl-5 ≈ FeAl-10 ? FeAl-1, which could be attributed to their different pore structural properties and reactive sites caused by the different phase interaction between iron species and the γ-Al2O3. The generation of trichloronaphthalenes (1,2,3-TrCN and 1,2,4-TrCN, i.e. CN-13 and CN-14), dichloronaphthalenes (1,2-DiCN, 1,3-DiCN, 1,4-DiCN and 2,3-DiCN, i.e. CN-3, CN-4, CN-5 and CN-10) and monochloronaphthalenes (1-MoCN and 2-MoCN, i.e. CN-1 and CN-2) suggested the occurrence of successive hydrodechlorination reactions. The amount of CN-14 exceeded that of CN-13 from 71.5% to 77.7% across the three different systems, revealing the preferred occurrence of the first hydrodechlorination step at the β-position. This is dissimilar to the preference at the α-position observed during the dechlorination of octachloronaphthalene (CN-75) over micro/nano Fe3O4. The structural differences between one-side and two-side fully-chlorinated aromatic rings would have a pronounced impact on the reactivity of the chlorine substitution position. The major hydrodechlorination pathway was judged to be CN-27 → CN-14 → CN-4 → CN-2. Additionally, the detected 1,2,3,4,6-pentachloronaphthalene (CN-50) and 1,2,4,6/7-tetrachloronaphthalenes (CN-33/34) suggested the reverse chlorination reaction also happened while the hydrodechlorination reaction was occurring. The C-Cl bond dissociation energies (BDEs) of the parent and daughter polychlorinated naphthalene (PCN) congener were calculated using density functional theory (DFT), to achieve a deeper understanding of a different product yield distribution.
The Bergman reaction as a synthetic tool: Advantages and restrictions
Bowles, Daniel M,Palmer, Grant J,Landis, Chad A,Scott, John L,Anthony, John E
, p. 3753 - 3760 (2007/10/03)
The Bergman cycloaromatization reaction efficiently converts easily prepared acyclic enediynes into aromatic rings. In order to prepare larger, functionalized fused aromatic systems using this reaction, a thorough understanding of how functionalization affects cycloaromatization is necessary. We present here our studies on the influence of substituents at three different functionalization sites on cycloaromatization, and how these functional groups can be tailored to prepare more complex systems.
