Novel Synthesis and Molecular Structure of the Pyrene Isomer Dicyclohepta[<i>cd,gh</i>]pentalene (Azuleno[2,1,8‐<i>ija</i>]azulene)

Vogel, Emanuel; Wieland, Herbert; Schmalstieg, Lutz; Lex, Johann

doi:10.1002/anie.198407171

Cited by 28 publications

(18 citation statements)

References 23 publications

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“…Scheme 8. a) Synthesis of compound 47; b) synthesis of compound 53. t BuOK: potassium tert-butoxide. [49,52] Scheme 9. a) Isomeric molecules of cyclohepta[a]phenalene; b) synthesis of compound 59b. LDCHA: lithium dicyclohexylamide; PhSSPh: diphenyl disulfide; LDA: lithium diisopropylamide; MCPBA: meta-chloroperbenzoic acid.…”

Section: Scholl-type Cyclodehydrogenationmentioning

confidence: 99%

Synthesis of Defective Nanographenes Containing Joined Pentagons and Heptagons

Fei

Liu

2022

Advanced Science

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Dedicated to Professor Klaus Müllen on the occasion of his 75 birthdayDefective nanographenes containing joined pentagons and heptagons exhibit striking physicochemical properties from both experimental and theoretical perspectives compared with their pure hexagonal counterparts. Thus, the synthesis and characterization of these unique polyarenes with well-defined defective topologies have attracted increasing attention. Despite extensive research on nonalternant molecules since the last century, most studies focused on the corresponding mutagenic and carcinogenic activities. Recently, researchers have realized that the defective domain induces geometric bending and causes electronic perturbation, thus leading to significant alteration of the photophysical properties. This review discusses the synthesis and characterization of small nonalternant polycyclic hydrocarbons in the early stage and recent developments in embedding pentagon-heptagon (5-7) pairs into large carbon skeletons through in-solution chemistry.

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Section: Scholl-type Cyclodehydrogenationmentioning

confidence: 99%

Synthesis of Defective Nanographenes Containing Joined Pentagons and Heptagons

Fei

Liu

2022

Advanced Science

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“…Pertinent to this report is the crystal structure of the parent azulene (Robertson et al, 1962), which crystallizes in the monoclinic space group P2 1 /a. Other related structures, also having monoclinic space groups, include two variously substituted azulenes (Lohr et al, 1984;Wong et al, 1984) which both crystallize in the space group P2 1 /c, and a fused bis-azulene (Vogel et al, 1984) found in the space group P2 1 /n. This is in contrast with the orthorhombic structure of the dibromoazulene presented here.…”

Section: Commentmentioning

confidence: 99%

1,3-Dibromoazulene

et al. 2005

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In the structure of 1,3‐dibromoazulene, C10H6Br2, the planar molecule sits on a crystallographic mirror plane. The Br atoms are attached to the five‐membered ring adjacent to the ring fusion. Head‐to‐tail charge–charge interactions due to partial positive charges on ring H atoms and partial negative charges within the aromatic ring system attract adjacent 1,3‐dibromoazulene molecules together. This causes them to arrange themselves in a zigzag pattern that allows close packing of the oppositely charged groups.

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“…However, we cannot ignore that thermal decomposition of BCA occurs to 30% as decarbonylation to anthracene and carbon monoxide, but 70% of the annulene is deoxygenated to give, via the 1,2-dioxetane obtained by connecting with chemical bonds atoms O1-O2 and C 15-C16, the pyrene isomer dicyclohepta [cd,gh]pentalene, alternatively named azuleno[2,1,8-ija]azulene . The latter is a planar, centrosymmetric molecule, whose structure, studied by X-ray diffraction (Vogel, Wieland, Schmalstieg & Lex, 1984), comprises indeed two seven-and two five-membered rings.…”

Section: The Topological Analysis Of Oex Pmentioning

confidence: 99%

Bond lengths, and beyond

Destro¹,

Merati²

1995

Acta Crystallogr B Struct Sci

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The degree of precision and accuracy in molecular geometry attainable with modem X-ray diffraction and cryogenic techniques is documented by presenting the results of a low-temperature study of syn-l,6:8,13 biscarbonyl[ 14]annulene, tricycio[8.4.1.13,8 ]hexadeca-2,4,6,8,10,12,14-heptaene-15,16-dione. Intensity data up to sin0/2 = 1.14,~, -I have been measured from a spherical crystal at T --19 K. Their multipolar analysis, up to the octopole level for C and O atoms, and to quadrupoles for anisotropically described H atoms, has led to precisions in the coordinates of the heavy atoms which are better than 0.0004,~,. Root mean square (r.m.s.) amplitudes of vibration for C and O atoms have been determined to a precision of ca 0.0006 ,~. Based on the least-squares or's, uncertainties for the C--C and C--O bond lengths are 0.0005 ,~, and those of the C--H bond distances 0.006--0.007 ,A,. The topological properties of the experimentally derived charge density of the annulene molecule in the crystal have been determined by evaluating the location and nature of its critical points (points where Vp = 0). Contour maps of ,Oex p and its negative Laplacian (--VZ,Oexp) are presented. The occurrence of a bond critical point midway between the two C atoms of the carbonyl bridges seems to indicate the existence of a chemically unexpected weak bond between the two C atoms.

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Novel Synthesis and Molecular Structure of the Pyrene Isomer Dicyclohepta[cd,gh]pentalene (Azuleno[2,1,8‐ija]azulene)

Cited by 28 publications

References 23 publications

Synthesis of Defective Nanographenes Containing Joined Pentagons and Heptagons

Synthesis of Defective Nanographenes Containing Joined Pentagons and Heptagons

1,3-Dibromoazulene

Bond lengths, and beyond

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