scholarly journals [Se(CH2C(O)CH3)3][B12F11NH3]: The first selenium cation with three β-ketone substituents

2020 ◽  
Vol 76 (2) ◽  
pp. 221-224
Author(s):  
Carsten Jenne ◽  
Marc C. Nierstenhöfer
Keyword(s):  
Hydrogen Bonds ◽  
Functional Groups ◽  
Diethyl Ether ◽  
Selenium Atom ◽  
Selenium Compound ◽  
Weakly Coordinating

The reaction of [Se8][B12F11NH3]2 with acetone and subsequent crystallization from acetone/diethyl ether yielded the selenium cation [Se(CH2C(O)CH3)3]+ as a by-product, which is stabilized by the weakly coordinating undecafluorinated anion [B12F11NH3]−. While attempting to crystallize pure [Se8][B12F11NH3]2, the structure of the isolated product, namely, tris(2-oxopropyl)selenium 1-ammonioundecafluorododecaborate, was surprising. The cation [Se(CH2C(O)CH3)3]+ represents the first example for a cationic selenium compound with three ketone functional groups located in the β-position with respect to the selenium atom. The cation possesses almost trigonal–pyramidal C 3 symmetry and forms hydrogen bonds to the ammonio group of the anion.

scholarly journals N′-Cyclododecylidenepyridine-4-carbohydrazide

2012 ◽  
Vol 68 (4) ◽  
pp. o1205-o1205
Author(s):  
Andreas Lemmerer ◽  
Joel Bernstein ◽  
Volker Kahlenberg
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Functional Groups ◽  
Title Compound ◽  
Antituberculosis Drug ◽  
Compound C

The title compound, C18H27N3O, is a derivative of the antituberculosis drug isoniazid (systematic name: pyridine-4-carbohydrazidei). The crystal structure consists of repeatingC(4) chains along thebaxis, formed by N—H...O hydrogen bonds with adjacent amide functional groups that are related by ab-glide plane. The cyclododecyl ring has the same approximately `square' conformation, as seen in the parent hydrocarbon cyclododecane.

scholarly journals Aggregation of coronene: the effect of carboxyl and amine functional groups

2021 ◽  
Author(s):  
C. F. O. Correia ◽  
J. M. C. Marques ◽  
M. Bartolomei ◽  
F. Pirani ◽  
E. Maçôas ◽  
...  
Keyword(s):  
Global Optimization ◽  
Hydrogen Bonds ◽  
Functional Groups ◽  
Weak Hydrogen Bonds ◽  
Amine Groups

Global optimization reveals that aggregation is enhanced for coronene substituted with carboxylic and amine groups, which is due to the influence of weak hydrogen bonds and stronger electrostatic contributions.

scholarly journals Crystal structures oftrans-dichloridotetrakis[1-(2,6-diisopropylphenyl)-1H-imidazole-κN3]iron(II),trans-dibromidotetrakis[1-(2,6-diisopropylphenyl)-1H-imidazole-κN3]iron(II) andtrans-dibromidotetrakis[1-(2,6-diisopropylphenyl)-1H-imidazole-κN3]iron(II) diethyl ether disolvate

2014 ◽  
Vol 70 (8) ◽  
pp. 72-76
Author(s):  
Roger Mafua ◽  
Titus Jenny ◽  
Gael Labat ◽  
Antonia Neels ◽  
Helen Stoeckli-Evans
Keyword(s):  
Hydrogen Bonds ◽  
Diethyl Ether ◽  
Solvent Molecule ◽  
Dihedral Angles ◽  
Halide Ions ◽  
Π Interactions ◽  
Close Proximity ◽  
Coordination Spheres ◽  
Solvent Molecules ◽  
Compound Ii

The title compounds, [FeCl2(C15H20N2)4], (I), [FeBr2(C15H20N2)4], (II), and [FeBr2(C15H20N2)4]·2C4H10O, (IIb), respectively, all have triclinic symmetry, with (I) and (II) being isotypic. The FeIIatoms in each of the structures are located on an inversion center. They have octahedral FeX2N4(X= Cl and Br, respectively) coordination spheres with the FeIIatom coordinated by two halide ions in atransarrangement and by the tertiary N atom of four arylimidazole ligands [1-(2,6-diisopropylphenyl)-1H-imidazole] in the equatorial plane. In the two independent ligands, the benzene and imidazole rings are almost normal to one another, with dihedral angles of 88.19 (15) and 79.26 (14)° in (I), 87.0 (3) and 79.2 (3)° in (II), and 84.71 (11) and 80.58 (13)° in (IIb). The imidazole rings of the two independent ligand molecules are inclined to one another by 70.04 (15), 69.3 (3) and 61.55 (12)° in (I), (II) and (IIb), respectively, while the benzene rings are inclined to one another by 82.83 (13), 83.0 (2) and 88.16 (12)°, respectively. The various dihedral angles involving (IIb) differ slightly from those in (I) and (II), probably due to the close proximity of the diethyl ether solvent molecule. There are a number of C—H...halide hydrogen bonds in each molecule involving the CH groups of the imidazole units. In the structures of compounds (I) and (II), molecules are linkedviapairs of C—H...halogen hydrogen bonds, forming chains along theaaxis that encloseR22(12) ring motifs. The chains are linked by C—H...π interactions, forming sheets parallel to (001). In the structure of compound (IIb), molecules are linkedviapairs of C—H...halogen hydrogen bonds, forming chains along thebaxis, and the diethyl ether solvent molecules are attached to the chainsviaC—H...O hydrogen bonds. The chains are linked by C—H...π interactions, forming sheets parallel to (001). In (I) and (II), the methyl groups of an isopropyl group are disordered over two positions [occupancy ratio = 0.727 (13):0.273 (13) and 0.5:0.5, respectively]. In (IIb), one of the ethyl groups of the diethyl ether solvent molecule is disordered over two positions (occupancy ratio = 0.5:0.5).

PVC modification with new functional groups. Influence of hydrogen bonds on reactivity, stiffness and specific volume

Polymer ◽  
2002 ◽  
Vol 43 (9) ◽  
pp. 2631-2636 ◽  
Author(s):  
Miguel Herrero ◽  
Pilar Tiemblo ◽  
Juan Reyes-Labarta ◽  
Carmen Mijangos ◽  
Helmut Reinecke
Keyword(s):  
Hydrogen Bonds ◽  
Functional Groups ◽  
Specific Volume

scholarly journals Synthesis of per(5-N-carboxamide-5-dehydroxylmethyl)-β-cyclodextrins and their selective recognition ability utilizing multiple hydrogen bonds

2019 ◽  
Vol 55 (27) ◽  
pp. 3872-3875 ◽  
Author(s):  
Takashi Nakamura ◽  
Sota Yonemura ◽  
Tatsuya Nabeshima
Keyword(s):  
Hydrogen Bonds ◽  
Functional Groups ◽  
Anion Recognition ◽  
Binding Mode ◽  
Selective Recognition ◽  
Recognition Ability ◽  
Multiple Hydrogen Bonds

An amide cyclodextrin with anion recognition ability exhibits unique binding mode in which unsymmetrically arranged functional groups play distinctive roles.

The hydrogen-bonded complex bis(tert-butylammonium) 2,6-dichlorophenolate 2,4-dichlorophenol–2,4-dichlorophenolate tetrahydrofuran disolvate containing a chiralR53(10) hydrogen-bonded ring as a supramolecular synthon

2016 ◽  
Vol 72 (10) ◽  
pp. 720-723 ◽  
Author(s):  
Xiao-Qing Cai ◽  
Bei Tian ◽  
Jian-Nan Zhang ◽  
Zhi-Min Jin
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Functional Groups ◽  
High Probability ◽  
Internal Symmetry ◽  
Supramolecular Synthon ◽  
Π Interactions ◽  
Graph Set ◽  
Hydrogen Bonded

A fixed hydrogen-bonding motif with a high probability of occurring when appropriate functional groups are involved is described as a `supramolecular hydrogen-bonding synthon'. The identification of these synthons may enable the prediction of accurate crystal structures. The rare chiral hydrogen-bonding motifR53(10) was observed previously in a cocrystal of 2,4,6-trichlorophenol, 2,4-dichlorophenol and dicyclohexylamine. In the title solvated salt, 2C4H12N+·C6H3Cl2O−·(C6H3Cl2O−·C6H4Cl2O)·2C4H8O, five components, namely twotert-butylammonium cations, one 2,4-dichlorophenol molecule, one 2,4-dichlorophenolate anion and one 2,6-dichlorophenolate anion, are bound by N—H...O and O—H...O hydrogen bonds to form a hydrogen-bonded ring, with the graph-set motifR53(10), which is further associated with two pendant tetrahydrofuran molecules by N—H...O hydrogen bonds. The hydrogen-bonded ring has internal symmetry, with a twofold axis running through the centre of the 2,6-dichlorophenolate anion, and is isostructural with a previous and related structure formed from 2,4-dichlorophenol, dicyclohexylamine and 2,4,6-trichlorophenol. In the title crystal, helical columns are built by the alignment and twisting of the chiral hydrogen-bonded rings, along and across thecaxis, and successive pairs of rings are associated with each other through C—H...π interactions. Neighbouring helical columns are inversely related and, therefore, no chirality is sustained, in contrast to the previous case.

Synthesis of Monofunctionalized Calix[5]arenes

Synthesis ◽  
2017 ◽  
Vol 50 (03) ◽  
pp. 676-684 ◽  
Author(s):  
Arne Lützen ◽  
Björn Ingenfeld ◽  
Steffen Straub ◽  
Christopher Frömbgen
Keyword(s):  
Hydrogen Bonds ◽  
Functional Groups ◽  
Functional Group ◽  
Building Blocks ◽  
Cone Conformation ◽  
Oh Groups ◽  
Tert Butyl ◽  
Fragment Condensation ◽  
Molecular Architectures ◽  
Phenolic Oh Groups

Seven OH-free and O-permethylated monofunctionalized calix[5]arenes carrying either additional methyl or tert-butyl groups are prepared following fragment condensation protocols. This strategy proves to be superior to previous approaches. Calix[5]arenes with free OH groups all adopt a cone conformation stabilized by a seam of hydrogen bonds at the lower rim. Post-condensation modifications, i.e., methylation of phenolic OH groups or functional group interconversions can also be achieved. Bulky tert-butyl groups are also found to stabilize the cone conformations of O-methylated compounds. These compounds offer versatile functional groups that make these concave molecules interesting building blocks for the synthesis of more sophisticated molecular architectures.

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