scholarly journals Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

2020 ◽  
Vol 16 ◽  
pp. 2212-2259 ◽  
Author(s):  
Shakeel Alvi ◽  
Rashid Ali
Keyword(s):  
Materials Science ◽  
Crystal Packing ◽  
Review Article ◽  
Physiochemical Properties ◽  
Facial Selectivity ◽  
Sanskrit Word ◽  
Phenyl Rings ◽  
Polycyclic Aromatic ◽  
Synthetic Approaches ◽  
Near Future

Since the first synthetic report in 2003 by Sakurai et al., sumanene (derived from the Indian ‘Hindi as well as Sanskrit word’ “Suman”, which means “Sunflower”), a beautifully simple yet much effective bowl-shaped C 3-symmetric polycyclic aromatic hydrocarbon having three benzylic positions clipped between three phenyl rings in the triphenylene framework has attracted a tremendous attention of researchers worldwide. Therefore, since its first successful synthesis, a variety of functionalized sumanenes as well as heterosumanenes have been developed because of their unique physiochemical properties. For example, bowl-to-bowl inversion, bowl depth, facial selectivity, crystal packing, metal complexes, intermolecular charge transfer systems, cation–π complexation, electron conductivity, optical properties and so on. Keeping the importance of this beautiful scaffold in mind, we compiled all the synthetic routes available for the construction of sumanene and its heteroatom derivatives including Mehta’s first unsuccessful effort up to the latest achievements. Our major goal to write this review article was to provide a quick summary of where the field has been, where it stands at present, and where it might be going in near future. Although several reviews have been published on sumanene chemistry dealing with different aspects but this is the first report that comprehensively describes the ‘all-in-one’ chemistry of the sumanene architecture since its invention to till date. We feel that this attractive review article will definitely help the scientific community working not only in the area of organic synthesis but also in materials science and technology.

scholarly journals Exploitation of Baird Aromaticity and Clar’s Rule for Tuning the Triplet Energies of Polycyclic Aromatic Hydrocarbons

Chemistry ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 532-549
Author(s):  
Felix Plasser
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Excited States ◽  
Aromatic Hydrocarbons ◽  
Density Functional ◽  
Materials Science ◽  
Chemical Shifts ◽  
Qualitative Description ◽  
Triplet States ◽  
Excitation Energies ◽  
Polycyclic Aromatic

Polycyclic aromatic hydrocarbons (PAH) are a prominent substance class with a variety of applications in molecular materials science. Their electronic properties crucially depend on the bond topology in ways that are often highly non-intuitive. Here, we study, using density functional theory, the triplet states of four biphenylene-derived PAHs finding dramatically different triplet excitation energies for closely related isomeric structures. These differences are rationalised using a qualitative description of Clar sextets and Baird quartets, quantified in terms of nucleus independent chemical shifts, and represented graphically through a recently developed method for visualising chemical shielding tensors (VIST). The results are further interpreted in terms of a 2D rigid rotor model of aromaticity and through an analysis of the natural transition orbitals involved in the triplet excited states showing good consistency between the different viewpoints. We believe that this work constitutes an important step in consolidating these varying viewpoints of electronically excited states.

scholarly journals Crystal structures and conformations of two Diels–Alder adduct derivatives: 1,8-bis(thiophen-2-yl)-14-oxatetracyclo[6.5.1.02,7.09,13]tetradeca-2(7),3,5-trien-10-one and 1,8-diphenyl-14-oxatetracyclo[6.5.1.02,7.09,13] tetradeca-2,4,6-trien-10-one

2015 ◽  
Vol 71 (2) ◽  
pp. 213-216
Author(s):  
S. Gopinath ◽  
P. Narayanan ◽  
K. Sethusankar ◽  
Meganathan Nandakumar ◽  
Arasambattu K. Mohanakrishnan
Keyword(s):  
Crystal Packing ◽  
Rotation Axis ◽  
Alder Reaction ◽  
Ring System ◽  
Diels Alder ◽  
Compound I ◽  
Diels Alder Reaction ◽  
Phenyl Rings ◽  
Axis Parallel ◽  
Alder Adduct

The title compounds, C21H16O2S2(I) and C25H20O2(II), are products of a tandem `pincer' Diels–Alder reaction consisting of [2 + 2] cycloadditions between benzo[c]furan and cyclopentanone. Each comprises a fused tetracyclic ring system containing two five-membered rings (inenvelopeconformations with the O atom as the flap) and six-membered rings (inboatconformations). In addition, two thiophene rings in (I) and two phenyl rings in (II) are attached to the tetracyclic ring system. The cyclopentanone ring adopts atwistedconformation in (I) and anenvelopeconformation in (II). In (I), the thiophene rings are positionally disordered over two sets of sites, with occupancy ratios of 0.901 (2):0.099 (2) and 0.666 (2):0.334 (2). In (II), the oxygen atom of the cyclopentanone ring is rotationally disordered over two sites with an occupancy ratio of 0.579 (4):0.421 (4). The molecular structure of (I) is stabilized by an intramolecular C—H...O hydrogen bond, which generates anS(7) ring motif. In the crystal, the molecules are linkedviaweak C—H...O hydrogen bonds, which generateR22(16) ring motifs in (I) andC(8) chains in (II). In both structures, the crystal packing also features C—H...π interactions. The crystal studied of compound (I) was twinned by non-merohedry. The twin component is related by the twin law [−1 0 0 −0.101 1 −0.484 0 0 −1] operated by a twofold rotation axis parallel to thebaxis. The structure of (I) was refined with a twin scale factor of 0.275 (2).

4-(Bromomethyl)benzophenone

2007 ◽  
Vol 63 (3) ◽  
pp. o1188-o1189 ◽  
Author(s):  
Wei-Jian Xu ◽  
Yang-Ling Zang ◽  
Guo-Liang Wu ◽  
Sheng-Pei Su ◽  
De-Yue Qiu
Keyword(s):  
Crystal Structure ◽  
Carbon Tetrachloride ◽  
Dihedral Angle ◽  
Structure Analysis ◽  
Title Compound ◽  
Crystal Packing ◽  
Crystal Structure Analysis ◽  
X Ray ◽  
Compound C ◽  
Phenyl Rings

The title compound, C14H11BrO, was synthesized by the reaction of 4-methylbenzophenone and bromine in carbon tetrachloride. X-ray crystal structure analysis reveals that the benzene and phenyl rings form a dihedral angle of 59.53 (6)°, and the crystal packing is stabilized by intermolecular C—H...π interactions.

scholarly journals Crystal structure of 2-(2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ylidene)acetonitrile

2015 ◽  
Vol 71 (10) ◽  
pp. o792-o793
Author(s):  
K. Priya ◽  
K. Saravanan ◽  
S. Kabilan ◽  
S. Selvanayagam
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Chair Conformation ◽  
Equatorial Orientation ◽  
Amino Group ◽  
Phenyl Rings

In the title 3-azabicyclononane derivative, C22H22N2, both the fused piperidine and cyclohexane rings adopt a chair conformation. The phenyl rings attached to the central azabicylononane fragment in an equatorial orientation are inclined to each other at 23.7 (1)°. The amino group is not involved in any hydrogen bonding, so the crystal packing is stabilized only by van der Waals forces.

scholarly journals Crystal structure of two N′-(1-phenylbenzylidene)-2-(thiophen-3-yl)acetohydrazides

2019 ◽  
Vol 75 (8) ◽  
pp. 1090-1095
Author(s):  
Trung Vu Quoc ◽  
Linh Nguyen Ngoc ◽  
Duong Tran Thi Thuy ◽  
Manh Vu Quoc ◽  
Thien Vuong Nguyen ◽  
...  
Keyword(s):  
Torsion Angle ◽  
Phenyl Ring ◽  
Spectroscopic Data ◽  
Crystal Packing ◽  
Thiophene Ring ◽  
Hirshfeld Surface ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Crystal And Molecular Structures ◽  
Phenyl Rings

The synthesis, spectroscopic data, crystal and molecular structures of two N′-(1-phenylbenzylidene)-2-(thiophen-3-yl)acetohydrazides, namely N′-[1-(4-hydroxyphenyl)benzylidene]-2-(thiophen-3-yl)acetohydrazide, C13H10N2O2S, (3a), and N′-[1-(4-methoxyphenyl)benzylidene]-2-(thiophen-3-yl)acetohydrazide, C14H14N2O2S, (3b), are described. Both compounds differ in the substituent at the para position of the phenyl ring: –OH for (3a) and –OCH3 for (3b). In (3a), the thiophene ring is disordered over two orientations with occupancies of 0.762 (3) and 0.238 (3). The configuration about the C=N bond is E. The thiophene and phenyl rings are inclined by 84.0 (3) and 87.0 (9)° for the major- and minor-occupancy disorder components in (3a), and by 85.89 (12)° in (3b). Although these dihedral angles are similar, the conformation of the linker between the two rings is different [the C—C—C—N torsion angle is −ac for (3a) and −sc for (3b), while the C6—C7—N9—N10 torsion angle is +ap for (3a) and −sp for (3b)]. A common feature in the crystal packing of (3a) and (3b) is the presence of N—H...O hydrogen bonds, resulting in the formation of chains of molecules running along the b-axis direction in the case of (3a), or inversion dimers for (3b). The most prominent contributions to the surface contacts are those in which H atoms are involved, as confirmed by an analysis of the Hirshfeld surface.

scholarly journals Exploitation of Baird Aromaticity and Clar's Rule for Tuning the Triplet Energies of Polycyclic Aromatic Hydrocarbons

2021 ◽  
Author(s):  
Felix Plasser
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Excited States ◽  
Aromatic Hydrocarbons ◽  
Density Functional ◽  
Materials Science ◽  
Chemical Shifts ◽  
Qualitative Description ◽  
Triplet States ◽  
Excitation Energies ◽  
Polycyclic Aromatic

Polycyclic aromatic hydrocarbons (PAH) are a prominent substance class with a variety of applications in molecular materials science. Their electronic properties crucially depend on the bond topology in ways that are often highly non-intuitive. Here, we study, using density functional theory, the triplet states of four PAHs based on the biphenylene motif finding dramatically different triplet excitation energies for closely related isomeric structures. These differences are rationalised using a qualitative description of Clar sextets and Baird quartets, quantified in terms of nucleus independent chemical shifts, and represented graphically through a recently developed method for visualising chemical shielding tensors (VIST). These results are further interpreted in terms of a 2D rigid rotor model of aromaticity and through an analysis of the natural transition orbitals involved in the triplet excited states showing good consistency between the different viewpoints. We believe that this work constitutes an important step in consolidating these varying viewpoints of electronically excited states.

scholarly journals Crystal structure of 2-hydroxy-2-phenylacetophenone oxime

2021 ◽  
Vol 77 (1) ◽  
pp. 66-69
Author(s):  
Nurcan Akduran
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Phenyl Ring ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Oxime Group ◽  
Phenyl Rings ◽  
Ring Interaction ◽  
Van Der Waals Contacts

The title compound [systematic name: 2-(N-hydroxyimino)-1,2-diphenylethanol], C14H13NO2, consists of hydroxy phenylacetophenone and oxime units, in which the phenyl rings are oriented at a dihedral angle of 80.54 (7)°. In the crystal, intermolecular O—HOxm...NOxm, O—HHydr...OHydr, O—H′Hydr...OHydr and O—HOxm...OHydr hydrogen bonds link the molecules into infinite chains along the c-axis direction. π–π contacts between inversion-related of the phenyl ring adjacent to the oxime group have a centroid–centroid separation of 3.904 (3) Å and a weak C—H...π(ring) interaction is also observed. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (58.4%) and H...C/C...H (26.4%) contacts. Hydrogen bonding and van der Waals contacts are the dominant interactions in the crystal packing.

scholarly journals (Z)-4-n-Butyl-2-(4-chlorobenzylidene)-2H-1,4-benzothiazin-3(4H)-one

IUCrData ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Mohamed Ellouz ◽  
Nada Kheira Sebbar ◽  
Younes Ouzidan ◽  
Manpreet Kaur ◽  
El Mokhtar Essassi ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Dihedral Angle ◽  
Intermolecular Interactions ◽  
Title Compound ◽  
Crystal Packing ◽  
Boat Conformation ◽  
Compound C ◽  
Phenyl Rings

In the title compound, C19H18ClNOS, the thiazin-3-one ring adopts a slightly distorted screw-boat conformation. An intramolecular C—H...S hydrogen bond encloses anS(6) ring and affects the overall conformation of the molecule. The dihedral angle between the two phenyl rings is 52.3 (2)°. In the crystal, weak C—H...O intermolecular interactions stabilize the crystal packing.

scholarly journals Crystal structure analysis of ethyl 6-(4-methoxyphenyl)-1-methyl-4-methylsulfanyl-3-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

2020 ◽  
Vol 76 (8) ◽  
pp. 1209-1212
Author(s):  
H. Surya Prakash Rao ◽  
Ramalingam Gunasundari ◽  
Jayaraman Muthukumaran
Keyword(s):  
Crystal Structure ◽  
Dihedral Angle ◽  
Structure Analysis ◽  
Title Compound ◽  
Crystal Packing ◽  
Crystal Structure Analysis ◽  
Dihedral Angles ◽  
Pyridine Moiety ◽  
Compound C ◽  
Phenyl Rings

In the title compound, C24H23N3O3S, the dihedral angle between the fused pyrazole and pyridine rings is 1.76 (7)°. The benzene and methoxy phenyl rings make dihedral angles of 44.8 (5) and 63.86 (5)°, respectively, with the pyrazolo[3,4-b] pyridine moiety. An intramolecular short S...O contact [3.215 (2) Å] is observed. The crystal packing features C—H...π interactions.

scholarly journals Stimuli-Responsive Graphene Nanohybrids for Biomedical Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Dinesh K. Patel ◽  
Yu-Ri Seo ◽  
Ki-Taek Lim
Keyword(s):  
Drug Delivery ◽  
Functional Groups ◽  
Hybrid Materials ◽  
Smart Materials ◽  
Biomedical Applications ◽  
Materials Science ◽  
High Surface ◽  
Single Layer ◽  
Stimuli Responsive ◽  
Physiochemical Properties

Stimuli-responsive materials, also known as smart materials, can change their structure and, consequently, original behavior in response to external or internal stimuli. This is due to the change in the interactions between the various functional groups. Graphene, which is a single layer of carbon atoms with a hexagonal morphology and has excellent physiochemical properties with a high surface area, is frequently used in materials science for various applications. Numerous surface functionalizations are possible for the graphene structure with different functional groups, which can be used to alter the properties of native materials. Graphene-based hybrids exhibit significant improvements in their native properties. Since functionalized graphene contains several reactive groups, the behavior of such hybrid materials can be easily tuned by changing the external conditions, which is very useful in biomedical applications. Enhanced cell proliferation and differentiation of stem cells was reported on the surfaces of graphene-based hybrids with negligible cytotoxicity. In addition, pH or light-induced drug delivery with a controlled release rate was observed for such nanohybrids. Besides, notable improvements in antimicrobial activity were observed for nanohybrids, which demonstrated their potential for biomedical applications. This review describes the physiochemical properties of graphene and graphene-based hybrid materials for stimuli-responsive drug delivery, tissue engineering, and antimicrobial applications.

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