The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

2020 ◽  
Vol 24 (10) ◽  
pp. 1139-1147
Author(s):  
Yang Mingyan ◽  
Wang Daoquan ◽  
Wang Mingan
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
The Other ◽  
Repulsive Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Effect ◽  
Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

Darstellung, 11B-, 13C-NMR- und Schwingungsspektren von Cs2[B6H5(p-C6H4(NO2))] und Cs2[B6H5(C6H3-l-(CH3)-5-(NO2))] sowie Kristallstruktur von (CH2Py2)[B6Cl5(p-C6H4(NO2))]·CH3CN / Preparation, 11B , 13C-NMR and Vibrational Spectra of Cs2[B6H5(p-C6H4(NO2))], Cs2[B6H5 (C6H3-1 -(CH3 )-5-(NO2))] and Crystal Structure of (CH2Py2)[B6Cl5(p-C6H4(NO2))]·CH3CN

2000 ◽  
Vol 55 (11) ◽  
pp. 1031-1036
Author(s):  
S. Zander ◽  
W. Preetz
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Deae Cellulose ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Derivatives Of ◽  
Ir And Raman

The first aryl derivatives of c/oso-hexahydrohexaborate are formed by reaction of [B6H6]2- with 1-bromo-4-nitrobenzene and 2-bromo-5-nitrotoluene in acetonitrile at 80 °C. Cs2[B6H5- (1,4-C6H4(NO2))] and Cs2[B6H5(C6H3-1-(CH3)-5-(NO2))] can be isolated by ion exchange chromatography on diethylaminoethyl (DEAE) cellulose. Further treatment with /V-chlorosuccinimide yields the perhalogenated derivative (CH2Py2)[B6Cl5(1,4-Ph(NO2))]CH3CN which has been characterized by X-ray diffraction analysis (orthorhombic, space group P2( 2,2t, a = 9.810(4), b - 14.412(3), c - 18.586(9) A, Z = 4). The 11B NMR spectra of all compounds are consistent with a monosubstituted B6-cluster. The IR and Raman spectra exhibit characteristic BB, BH, CH, CC and NO vibrations, respectively.

scholarly journals SYNTHESIS AND STRUCTURE OF TWO PALLADIUM(II) COMPLEXES BEARING ACETONITRILE AND N-HETEROCYCLIC CARBENE DERIVED FROM IMIDAZOLE

2019 ◽  
Vol 57 (4) ◽  
pp. 468
Author(s):  
Mai Thi Cam Truong ◽  
Chi Thi Thanh Nguyen
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
13C Nmr ◽  
Nmr Spectra ◽  
High Yield ◽  
13C Nmr Spectra ◽  
Trans Position ◽  
X Ray Diffraction ◽  
Imidazolium Chloride ◽  
X Ray

The reaction of [PdCl2(CH3CN)2] (1) with either 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride (IMes·HCl) or 1,3-bis(2,6-diisoproylphenyl)imidazolium chloride (IPr·HCl) in the present of Ag2O afforded two mixed monocarbene-CH3CN complexes, namely trans-[PdCl2(CH3CN)(IMes] (2) and trans-[PdCl2(CH3CN)(IPr)] (3), with the high yield (85-90%). The structure of 2 and 3 were elucidated by ESI mass, IR, 1H NMR and 13C NMR spectra. For 2, single-crystal X-ray diffraction study was also carried out. The results show that the CH3CN in 2 and 3 coordinates with Pd(II) via the N atom, the deprotonated imidazolium salts are bound up with Pd(II) via the C atom (NCHN) and occupy trans-position in comparison with the CH3CN.

Thiophene ring-opening reactions IV. Facile generation of novel ethyl 4-hydroxy-6-thioxonicotinate─1,3,4- thiadiazoline hybrids

2021 ◽  
Vol 18 ◽  
Author(s):  
Mohammed M. Abadleh ◽  
Ahmad H. Abdullah ◽  
Jalal A. Zahra ◽  
Salim S. Sabri ◽  
Firas F. Awwadi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectral Data ◽  
1H Nmr ◽  
13C Nmr ◽  
Ring Opening ◽  
Thiophene Ring ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Ring Opening Reactions

: A set of triethylammonium 4-oxo-6-pyridinethiolate–1,3,4-thiadiazoline hybrids (3a-e) were prepared via the reaction of ethyl 2-chloro-6-cyclopropyl-3- nitro-4-oxothieno[2,3-b]pyridine- 5-carboxylate (2) with the appropriate thiobenzoyl- hydrazide (1a-e) in acetonitrile and triethylamine. These hybrids were readily converted, under neutral mild conditions, into the corresponding 4-hydroxy-6-thioxopyridine –thiadiazoline hybrids (5a-e). The structures of the latter set are supported by HRMS, 1H NMR and 13C NMR spectral data and further confirmed by single-crystal X-ray diffraction studies. Alkylation of these hybrids in the presence of triethylamine occurred exclusively at the 6-thioxosulfur, yielding the respective 6-sulfanyl derivatives (6a-c).

Interactions de l'ion Ag+ avec la glutarimide

1984 ◽  
Vol 62 (7) ◽  
pp. 1287-1291 ◽  
Author(s):  
Johanne Perron ◽  
André L. Beauchamp
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectrum ◽  
Nmr Spectra ◽  
The Other ◽  
Mirror Plane ◽  
Bond Orders ◽  
X Ray Diffraction ◽  
Complex Species ◽  
X Ray ◽  
C Nmr

The 1:1 complex formed between Ag+ ions and glutarimide was investigated by X-ray diffraction, infrared spectroscopy, and 1H and 13C nmr. The crystals are monoclinic, C2/c, a = 13.497(3) Å, b = 9.503(2) Å, c = 9.600(4) Å, β = 92.30(3)°, Z = 4 molecules per cell. The structure was refined on 1086 nonzero [Formula: see text] reflections to R = 0.027. One half of the Ag atoms are linearly coordinated to the N atoms of two deprotonated glutarimide ligands, whereas the other half are surrounded by an approximate tetrahedron of four carbonyl oxygens belonging to two adjacent [Glu–Ag–Glu]− units. The [Glu–Ag–Glu]− groups are joined by tetrahedrally coordinated Ag atoms into infinite chains along the c axis. Complexation introduces a number of changes in the infrared spectrum of glutarimide. They can be related to the disappearance of the N—H vibrator and the change of bond orders in the —C(O)—N—C(O)— portion of the ligand. The nmr spectra show that coordinated glutarimide retains a mirror plane when the Ag complex is dissolved in DMSO. This suggests that the O-bonded Ag atoms dissociate to a large extent in solution, leaving the linear [Glu–Ag–Glu]− ions as the major glutarimide complex species.

Experimental (13C NMR, 1H NMR, FT-IR, single-crystal X-ray diffraction) and DFT studies on 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione

2011 ◽  
Vol 83 (1) ◽  
pp. 472-477 ◽  
Author(s):  
Nevin Süleymanoğlu ◽  
Reşat Ustabaş ◽  
Yelda Bingöl Alpaslan ◽  
Fatih Eyduran ◽  
Cengiz Özyürek ◽  
...  
Keyword(s):  
Single Crystal ◽  
1H Nmr ◽  
13C Nmr ◽  
Dft Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

scholarly journals A molecular inclusion complex of atenolol with 2-hydroxypropyl-β-cyclodextrin: The production and characterization thereof

2007 ◽  
Vol 72 (8-9) ◽  
pp. 737-746 ◽  
Author(s):  
Vesna Nikolic ◽  
Ljubisa Nikolic ◽  
Mihajlo Stankovic ◽  
Agnes Kapor ◽  
Mirjana Popsavin ◽  
...  
Keyword(s):  
Inclusion Complex ◽  
1H Nmr ◽  
13C Nmr ◽  
Chemical Shifts ◽  
13C Nmr Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Inclusion ◽  
Ft Ir ◽  
Diffraction Patterns

The molecular inclusion complex of atenolol with 2-hydroxypropyl-?-cyclodextrin was synthesized using the coprecipitation method. The complex obtained was characterized by FT-IR, 1H-NMR, 13C-NMR spectroscopy, as well as by DSC and X-ray diffraction analysis. The DSC analysis confirmed the existence of the complex with the endothermic atenolol melting peak at about 155?C disappearing. The X-ray diffraction patterns of the complex and 2-hydroxypropyl-?-cyclodextrin were very similar, thus confirming the complete inclusion of the atenolol molecule within the cavity of the 2-hydroxypropyl-?-cyclodextrin. The peaks originating from atenolol were completely absent in the diffractogram of the complex. 1H-NMR and 13C-NMR spectra showed certain changes in the chemical shifts of protons and C atoms from atenolol and 2-hydroxypropyl-?-cyclodextrin, indicating that a complex had been formed and also which protons participated in the hydrogen bonds which formed the complex. The atenolol solubility in water was improved (254 mg complex cm-3, i.e., 37.5 mg atenolol cm-3), and in pH 3 HCl solution (251 mg complex cm-3, i.e., 37 mg atenolol cm-3) when compared to pure atenolol, and even when compared to the atenolol complex with ?-cyclodextrin. The increased solubility ensures greater bioavailability of the active component and, due to the low solubility, significantly corrects for the lack of the basic active substance and, simultaneously, increases its overall therapeutic effect, combined with reduced side effects. .

Reactions of PO(NCS)3 with 4-Hydroxy-1,3-dioxanes. Crystal Structure of rel-(2S,4R,5S,6S)-2,6-Diethyl-5-methyl-4-(N'-benzylthioureido)-1,3-dioxane

1992 ◽  
Vol 57 (6) ◽  
pp. 1299-1313 ◽  
Author(s):  
Juraj Bernát ◽  
Ladislav Kniežo ◽  
Gabriela Birošová ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Nmr Spectra ◽  
Crystalline Form ◽  
The Other ◽  
Axial Position ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Alkyl Groups

Substituted 4-hydroxy-1,3-dioxanes II react rapidly with PO(NCS)3 to give 4-isothiocyanato-1,3-dioxanes III. The 1H NMR spectra showed that in the isothiocyanate IIIa the predominant stereoisomer has its NCS group in axial position. The addition of benzylamine to the isothiocyanates IIIa and IIIb gave uniform thioureas IVa and IVb with equatorial alkyl groups at 2 and 6 positions and axial thioureido group at 4 position. On the other hand, the isothiocyanate IIIc reacts with benzylamine to give a mixture of three stereoisomeric thioureas V,VI, and VIII. The structure of VI was proved by means of X-ray diffraction analysis; in crystalline form the molecules of VI are present as H-bonded dimers (N-H...O).

Anodische Oxidation von 2-Thiobarbitursäuren unter Bildung neuartiger, tetracyclischer Dimerer / Anodic Oxidation of 2-Thiobarbituric Acids under Formation of New Tetracyclic Dimers

2002 ◽  
Vol 57 (2) ◽  
pp. 215-225 ◽  
Author(s):  
Hans Günter Thomas ◽  
Michael Rasp ◽  
Gerhard Raabe
Keyword(s):  
Anodic Oxidation ◽  
Nmr Spectra ◽  
Barbituric Acid ◽  
The Other ◽  
Electrolysis Cell ◽  
X Ray Diffraction ◽  
X Ray

2-Thiobarbituric acids 1 can be dimerized anodically in acceptable yields if the special ultrasonic electrolysis cell described here is used. In some cases two isomeric dimers 2 and 4 were isolated. 2 is of the same type as the corresponding barbituric acid dimers. The other dimer 4 has a completely different, tetracyclic structure characterized by NMR spectra and X-ray diffraction. The mechanism postulated for the formation of the tetracyclic dimers is supported by cyclovoltammetric measurements.

Characterization of the ionic clathrate hydrate of tetra-n-butylammonium acrylate

2015 ◽  
Vol 93 (9) ◽  
pp. 954-959 ◽  
Author(s):  
Sanehiro Muromachi ◽  
Masato Kida ◽  
Satoshi Takeya ◽  
Yoshitaka Yamamoto ◽  
Ryo Ohmura
Keyword(s):  
Nmr Spectra ◽  
Clathrate Hydrate ◽  
Unit Cell ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Water ◽  
C Nmr ◽  
The Ideal

The ionic clathrate hydrate of tetra-n-butylammonium (TBA) acrylate was characterized using single-crystal X-ray diffraction, elemental analysis, and nuclear magnetic resonance (NMR) spectroscopy. The crystal structure of TBA acrylate was Jeffrey’s type III and tetragonal P42/n, with a 33.076(7) × 33.076(7) × 12.170(2) Å3 unit cell. The volume of the unit cell was 13315(5) Å3, which is almost twice that of the ideal structure. The TBA cation was disordered and located in two types of fused cages. Although the acrylate anion was located in a pentagonal dodecahedral cage neighboring the TBA cation, there is a residual acrylate anion that could be around the other TBA cation in the unit cell. Solid-state 13C NMR spectra showed that the TBA cation was clearly disordered at 173 K, but not at 239 K. NMR peaks from the acrylate anion were not observed at either temperature. This is probably because of the strong restriction on the acrylate anion by hydrogen bonding with the lattice water. Some of the characteristics of the anion and cation of the ionic guest incorporated in the hydrate structure have yet to be defined. Further research is needed to clarify complexation of the ionic clathrate hydrate and the ionic guest, and the resulting structure.

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