Chair-form six-membered ring attached diequatorially to five-coordinate phosphorus. 1H NMR and x-ray crystallographic study

1991 ◽  
Vol 113 (20) ◽  
pp. 7800-7802 ◽  
Author(s):  
Yande Huang ◽  
Atta M. Arif ◽  
Wesley G. Bentrude
Keyword(s):  
1H Nmr ◽  
Membered Ring ◽  
Chair Form ◽  
X Ray ◽  
Crystallographic Study

X-Ray crystallographic study of a 1,3,2-dioxaphosphorinane dimer containing five-coordinated phosphorus in the 12-membered ring

1993 ◽  
Vol 4 (2-3) ◽  
pp. 271-278 ◽  
Author(s):  
Yande Huang ◽  
Alan E. Sopchik ◽  
Atta M. Arif ◽  
Wesley G. Bentrude
Keyword(s):  
Membered Ring ◽  
X Ray ◽  
Crystallographic Study

Diterpene Imines. The Preparation of 2-Azalauren-1-ene and the Facile Autoxidation of 6-Azadihydrorimuene

1990 ◽  
Vol 43 (4) ◽  
pp. 719 ◽  
Author(s):  
AR Hayman ◽  
LR Hanton ◽  
RT Weavers
Keyword(s):  
Formic Acid ◽  
Membered Ring ◽  
Keto Acid ◽  
X Ray ◽  
Model Studies ◽  
Crystallographic Study

2-Azalauren-1-ene (2) has been synthesized from keto acid (5), but attempts to generate its C15 epimer (19) have produced only (2). Model studies of imine production by treatment of a rimuene -derived keto acid (3) with iodosylbenzene /formic acid have produced a hydroxy imine (11), a conjugated imine (13), and a keto lactam (12) which has a ten-membered ring. An X-ray crystallographic study which proves the structure of (12) is described. Data in support of the intermediacy of imine (7) (6-azadihydrorimuene) in the production of (11), (12) and (13) have been obtained.

Synthesis and Characterisation of [(en)2Co]3+ Complexes Coordinated by Substituted Thiourea Ligands

2013 ◽  
Vol 66 (8) ◽  
pp. 944 ◽  
Author(s):  
Lee Roecker ◽  
Mohammed Aiyegbo ◽  
Aladdin Al-Haddad ◽  
Emily Fletcher ◽  
Ravi Kc ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Coordination Mode ◽  
Membered Ring ◽  
State Structure ◽  
X Ray ◽  
Coordination Isomers ◽  
Bond Trans ◽  
Perchlorate Salt

Substituted thiourea ligands bind in a bidentate manner forming a four-membered ring through the sulfur atom and a deprotonated thiourea nitrogen atom when reacted with [(en)2Co(OSO2CF3)2]+ in tetramethylene sulfone. Reaction of unsymmetrical ligands results in the formation of coordination isomers, some of which can be separated by column chromatography using Sephadex SPC-25. Coordination isomers are easily distinguishable based on visible and 1H NMR spectroscopy . Twelve para-substituted and one meta-substituted ligands were studied: N,N′-dibenzylthiourea (1a); N-(R)phenyl-N′-benzylthiourea {R = H (2a), NO2 (2b), CH3 (2c)}; N-(R)phenyl-N′-(R′)phenylthiourea {R, R′: H, H (3a), H, CH3 (3b), OCH3, NO2 (3c), CH3, NO2 (3d)}; N-methyl-N′-(R)phenylthiourea {R = H (4a), CH3 (4b), OCH3 (4c), NO2 (4d), 3-CH3 (4e)}. The solid state structure (X-ray) of one isomer of Co-4a as its perchlorate salt confirms the coordination mode suggested by 1H NMR spectroscopy and shows that the Co–N bond trans to the coordinated thiourea sulfur induces a structural trans effect of 0.019 Å.

scholarly journals A63,65Cu and 127I Nuclear Quadrupole Resonance and X-Ray Crystallographic Study of a Low-Temperature Phase of the (2-picoline) Copper (I) Iodide Dimer

1992 ◽  
Vol 47 (1-2) ◽  
pp. 106-116
Author(s):  
Augustin Habiyakare ◽  
Edwin A. C. Lücken ◽  
Gerald Bernardinelli
Keyword(s):  
Low Temperature ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Membered Ring ◽  
Temperature Phase ◽  
X Ray ◽  
Crystallographic Study ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole ◽  
Low Temperature Phase

AbstractThe temperature-dependence of the 63Cu and 127I NQR spectra of bis(2-picoline) Copper(I) Iodide reveals the existence of a phase change at 250 K. An X-ray crystallographic study of the low-temperature phase reveals that the iodine-bridged dimeric structure, which was observed at room-temperature, is retained in the low temperature phase but that the bond-lengths and, particularly, the bond-angles of the central four-membered ring are considerably modified.

Beiträge zur Chemie des Schwefels, 116 [1]Kristall-und Molekülstrukturen von 1.2.4.5-Benzotetrathiepin und 3-Methyl-1.2.4.5-benzotetrathiepin / Contributions to the Chemistry of Sulfur, 116 [1]Crystal and Molecular Structures of 1,2,4,5-Benzotetrathiepine and 3-Methyl-1,2,4,5-benzotetrathiepine

1979 ◽  
Vol 34 (3) ◽  
pp. 426-430 ◽  
Author(s):  
F. Fehér ◽  
B. Engelen
Keyword(s):  
Structure Analysis ◽  
Spectroscopic Data ◽  
Membered Ring ◽  
Molecular Structures ◽  
Methyl Group ◽  
Chair Form ◽  
X Ray ◽  
Crystal And Molecular Structures

Abstract The structures of 1,2,4,5-benzotetrathiepine and 3-methyl-1,2,4,5-benzotetrathiepine were determined by X-ray structure analysis. The constitution of the molecules, which was proposed by way of spectroscopic data, could be verified. The conformation of the seven-membered rings is the chair form. The position of the methyl group in 3-methyl-1,2,4,5-benzotetrathiepine is equatorial with respect to the seven-membered ring. Details of the conformations are discussed. Bond distances and angles are compared with those in other molecules, which have similar structures.

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.

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