scholarly journals Polymorphism in secondary squaramides: on the importance of π-interactions involving the four membered ring

CrystEngComm ◽  
2018 ◽  
Vol 20 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Rafel Prohens ◽  
Anna Portell ◽  
Oriol Vallcorba ◽  
Mercè Font-Bardia ◽  
Antonio Bauzá ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Membered Ring ◽  
Supramolecular Assemblies ◽  
Dft Study ◽  
Squaric Acid ◽  
Π Interactions

We report the crystal structures of four new squaric acid derivatives, i.e. three polymorphs of 3,4-bis((2-(dimethylamino)ethyl)amino)cyclobut-3-ene-1,2-dione (1a–c) and a cocrystal with resorcinol. A DFT study has been also carried out to investigate the supramolecular assemblies.

Syntheses, crystal structures and supramolecular assemblies of two Cu(II) complexes based on a new heterocyclic ligand: Insights through C─H•••Cl and π•••π interactions

CrystEngComm ◽  
2022 ◽  
Author(s):  
Samit Pramanik ◽  
Sudipta Pathak ◽  
Antonio Frontera ◽  
Subrata Mukhopadhyay
Keyword(s):  
Crystal Structures ◽  
Supramolecular Assemblies ◽  
Spectroscopic Methods ◽  
Heterocyclic Ligand ◽  
Π Interactions

A heterocyclic ligand, N3L [4-(1-methylimidazole)-2,6-di(pyrazinyl)pyridine] has been synthesized and characterized by several spectroscopic methods. The ligand (N3L) was then used for the preparation of two complexes, namely, [Cu(N3L)Cl2] (complex 1)...

scholarly journals Different packing motifs mediated by weak interactions and polymorphism in the crystal structures of five 2-(benzylidene)benzosuberone derivatives

2019 ◽  
Vol 75 (11) ◽  
pp. 1741-1747
Author(s):  
Lewis S. Seaman ◽  
Cristiane F. da Costa ◽  
Marcus V. N. de Souza ◽  
Solange M. S. V. Wardell ◽  
James L. Wardell ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Benzene Ring ◽  
Weak Interactions ◽  
Structural Features ◽  
Membered Ring ◽  
Dihedral Angles ◽  
Π Interactions ◽  
Hirshfeld Surfaces ◽  
Key Features

The syntheses and crystal structures of five 2-benzylidene-1-benzosuberone [1-benzosuberone is 6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-one] derivatives, viz. 2-(4-methoxybenzylidene)-1-benzosuberone, C19H18O2, (I), 2-(4-ethoxybenzylidene)-1-benzosuberone, C20H20O2, (II), 2-(4-benzylbenzylidene)-1-benzosuberone, C25H22O2, (III), 2-(4-chlorobenzylidene)-1-benzosuberone, C18H15ClO, (IV) and 2-(4-cyanobenzylidene)-1-benzosuberone, C19H15NO, (V), are described. The conformations of the benzosuberone fused six- plus seven-membered ring fragments are very similar in each case, but the dihedral angles between the fused benzene ring and the pendant benzene ring differ somewhat, with values of 23.79 (3) for (I), 24.60 (4) for (II), 33.72 (4) for (III), 29.93 (8) for (IV) and 21.81 (7)° for (V). Key features of the packing include pairwise C—H...O hydrogen bonds for (II) and (IV), and pairwise C—H...N hydrogen bonds for (V), which generate inversion dimers in each case. The packing for (I) and (III) feature C—H...O hydrogen bonds, which lead to [010] and [100] chains, respectively. Weak C—H...π interactions consolidate the structures and weak aromatic π–π stacking is seen in (II) [centroid–centroid separation = 3.8414 (7) Å] and (III) [3.9475 (7) Å]. A polymorph of (I) crystallized from a different solvent has been reported previously [Dimmock et al. (1999) J. Med. Chem. 42, 1358–1366] in the same space group but with a packing motif based on inversion dimers resembling that seen in (IV) in the present study. The Hirshfeld surfaces and fingerprint plots for (I) and its polymorph are compared and structural features of the 2-benzylidene-1-benzosuberone family of phases are surveyed.

scholarly journals Crystal structures and Hirshfeld surface analysis of 2-(adamantan-1-yl)-5-(4-fluorophenyl)-1,3,4-oxadiazole and 2-(adamantan-1-yl)-5-(4-chlorophenyl)-1,3,4-oxadiazole

2019 ◽  
Vol 75 (5) ◽  
pp. 611-615 ◽  
Author(s):  
Lamya H. Al-Wahaibi ◽  
Aisha Alsfouk ◽  
Ali A. El-Emam ◽  
Olivier Blacque
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Surface Analysis ◽  
Interplanar Distance ◽  
Relative Orientation ◽  
Membered Ring ◽  
Hirshfeld Surface ◽  
Molecular Structures ◽  
Π Interactions ◽  
Hybrid Compounds

The crystal structures of the title adamantane-oxadiazole hybrid compounds, C18H19FN2O (I) and C18H19ClN2O (II), are built up from an adamantane unit and a halogenophenyl ring, [X = F (I), Cl (II)], in position 5 on the central 1,3,4-oxadiazole unit. The molecular structures are very similar, only the relative orientation of the halogenophenyl ring in comparison with the central five-membered ring differs slightly. In the crystals of both compounds, molecules are linked by pairs of C—H...N hydrogen bonds, forming inversion dimers with R 2 2(12) ring motifs. In (I) the dimers are connected by C—H...F interactions, forming slabs lying parallel to the bc plane. In (II), the dimers are linked by C—H...π and offset π–π interactions [interplanar distance = 3.4039 (9) Å], forming layers parallel to (10\overline{1}).

scholarly journals Design of New Schiff-Base Copper(II) Complexes: Synthesis, Crystal Structures, DFT Study, and Binding Potency toward Cytochrome P450 3A4

ACS Omega ◽  
2021 ◽  
Author(s):  
Tunde L. Yusuf ◽  
Segun D. Oladipo ◽  
Sizwe Zamisa ◽  
Hezekiel M. Kumalo ◽  
Isiaka A. Lawal ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Schiff Base ◽  
Crystal Structures ◽  
Dft Study ◽  
Cytochrome P450 3A4

Cyclisierung von Di(tert-butyl-methyl)ketazin zu 1,2-Diaza-3-bora- und 1,2-Diaza-3-sila-cyclopent-5-enen / Cyclization of Di(tert-butyl-methyl)ketazine to 1,2-Diaza-3-bora- and 1,2-Diaza-3-sila-cyclopent-5-enes

2006 ◽  
Vol 61 (10) ◽  
pp. 1261-1274 ◽  
Author(s):  
Florian Armbruster ◽  
Nina Armbruster ◽  
Uwe Klingebiel ◽  
Mathias Noltemeyer ◽  
Stefan Schmatz
Keyword(s):  
Crystal Structures ◽  
Quantum Chemical Calculations ◽  
Chlorine Atom ◽  
Quantum Chemical ◽  
Membered Ring ◽  
Substitution Product ◽  
Tert Butyl ◽  
Isomeric Structures

The results of quantum chemical calculations on lithium ketazides suggest mainly four isomeric structures with different modes of lithium coordination (A-D). A monolithium ketazide thf-adduct (1) was isolated supporting the results of the quantum chemical calculations. In reactions of the lithiated di(tert-butyl-methyl)ketazine with BCl3 and Cl2BPh, 1,2-aza-azonia-3-borata-cyclopent-5-enes (2, 3) were isolated. Substitution of a chlorine atom of 2 and 3 with t-BuLi leads to the formation of derivatives 4 and 5. HCl elimination from 2 with Et3N gives - via a diazaboracyclopentene (6) - a bicyclus 7. In the reaction of the dilithiated ketazine with F2BN(SiMe3)2, the diaza-boracyclopentene 8 is obtained while with Cl4Si, F3SiN(SiMe3)2, and Cl2SiMe2 the diazasilacyclopentenes 9 - 11 are generated. SiF4 reacts with the dilithium ketazide to give a spirocyclus (12). The monolithium ketazide and Cl2SiMe2 react at 30 °C to give a four-membered ring isomer of the substitution product which is formed via a 1,3-chlorine shift from silicon to carbon (13). A tetrameric silanolate was isolated as a by-product in this reaction. It gives evidence for the structure of lithium ketazide A. Crystal structures of 5, 7, 10, and 14 are reported.

scholarly journals Crystal structures of three newN-halomethylated quaternary ammonium salts

2015 ◽  
Vol 71 (10) ◽  
pp. 1230-1235
Author(s):  
Carolina Múnera-Orozco ◽  
Rogelio Ocampo-Cardona ◽  
David L. Cedeño ◽  
Rubén A. Toscano ◽  
Luz Amalia Ríos-Vásquez
Keyword(s):  
Crystal Structures ◽  
Intermolecular Interactions ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Compound I ◽  
Nlo Properties ◽  
Π Interactions

In the crystals of the titleN-halomethylated quaternary ammonium salts, C19H23IN+·I−, (I) [systematic name:N-(4,4-diphenylbut-3-en-1-yl)-N-iodomethyl-N,N-dimethylammonium iodide], C20H25IN+·I−, (II) [systematic name:N-(5,5-diphenylpent-4-en-1-yl)-N-iodomethyl-N,N-dimethylammonium iodide], and C21H27IN+·I−, (III) [systematic name:N-(6,6-diphenylhex-5-en-1-yl)-N-iodomethyl-N,N-dimethylammonium iodide], there are short I...I−interactions of 3.564 (4), 3.506 (1) and 3.557 (1) Å for compounds (I), (II) and (III), respectively. Compound (I) crystallizes in the Sohncke groupP21as an `enantiopure' compound and is therefore a potential material for NLO properties. In the crystal of compound (I), molecules are linked by C—H...I−and C—H...π interactions which, together with the I...I−interactions, lead to the formation of ribbons along [100]. In (II), there are only C—H...I−interactions which, together with the I...I−interactions, lead to the formation of helices along [010]. In (III), apart from the I...I−interactions, there are no significant intermolecular interactions present.

Syntheses, crystal structures, DNA binding, DNA cleavage and DFT study of Co(iii) complexes involving azo-appended Schiff base ligands

2018 ◽  
Vol 42 (20) ◽  
pp. 16571-16582 ◽  
Author(s):  
Saikat Banerjee ◽  
Roumi Patra ◽  
Pravat Ghorai ◽  
Paula Brandão ◽  
Sougata Ghosh Chowdhury ◽  
...  
Keyword(s):  
Schiff Base ◽  
Dna Binding ◽  
Crystal Structures ◽  
Dna Cleavage ◽  
Dft Study ◽  
Schiff Base Ligands

Herein, we have reported three new Co(iii) complexes involving azo-appended Schiff base ligands.

Crystal structures and Hirshfeld surface analysis of four 1,4-bis(methoxyphenyl)-2,3-diazabuta-1,3-dienes: comparisons of the intermolecular interactions in related compounds

2019 ◽  
Vol 234 (1) ◽  
pp. 59-71 ◽  
Author(s):  
Ligia R. Gomes ◽  
John N. Low ◽  
Nathasha R. de L. Correira ◽  
Thais C.M. Noguiera ◽  
Alessandra C. Pinheiro ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Intermolecular Interactions ◽  
Three Dimensional ◽  
Hirshfeld Surface ◽  
Dimensional Structure ◽  
Intermolecular Hydrogen Bonds ◽  
Π Interactions ◽  
Isomeric Compound ◽  
Related Compounds

Abstract The crystal structures of four azines, namely 1-3-bis(4-methoxyphenyl)-2,3-diaza-1,4-butadiene, 1, 1,3-bis(2,3-dimethoxyphenyl)-2,3-diaza-1,4-butadiene, 2, 1,3-bis(2-hydroxy-3-methoxyphenyl)-2,3-diaza-1,4-butadiene, 3, and 1,3-bis(2-hydroxy-4-methoxyphenyl)-2,3-diaza-1,4-butadiene, 4, are reported. Molecules of 3 and 4, and both independent molecules of 2, Mol A and Mol B, possess inversion centers. The central C=N–N=C units in each molecule is planar with an (E,E) conformation. The intermolecular interactions found in the four compounds are C–H···O, C–H–N, C–H---π and π---π interactions. However, there is no consistent set of intermolecular interactions for the four compounds. Compound, 1, has a two-dimensional undulating sheet structure, generated from C–H···O and C–H···N intermolecular hydrogen bonds. The only recognized intermolecular interaction in 2 is a C–H···O hydrogen bond, which results in a zig-zag chain of alternating molecules, Mol A and Mol B. While 3 forms a puckered sheet of molecules, solely via C–H···π interactions, its isomeric compound, 4, has a more elaborate three-dimensional structure generated from a combination of C–H···O hydrogen bonds, C–H···π and π···π interactions. The findings in this study, based on both PLATON and Hirshfeld approaches, for the four representative compounds match well the reported structural findings in the literature of related compounds, which are based solely on geometric parameters.

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