Substituent Effects on the Spectroscopic and Structural Parameters of Several New 1,3,2-Diazaphosphorinanes. Syntheses, Spectroscopic Characterization, and X-ray Crystallography

2006 ◽  
Vol 79 (10) ◽  
pp. 1604-1606 ◽  
Author(s):  
Khodayar Gholivand ◽  
Zahra Shariatinia ◽  
Fariba Yaghmaian ◽  
Halin Faramarzpour
Keyword(s):  
Structural Parameters ◽  
Substituent Effects ◽  
Spectroscopic Characterization ◽  
X Ray ◽  
X Ray Crystallography

Studies of molecular structure parameters of 20-piperidin-2-yl-5α-pregnan-3β,20-diol and its N-methyl derivative: two inhibitors of Δ24(25) sterol methyl transferase and Δ24(24′) sterol methyl reductase of Trypanosoma cruzi

2001 ◽  
Vol 57 (5) ◽  
pp. 714-721 ◽  
Author(s):  
Reinaldo Atencio ◽  
Gonzalo Visbal ◽  
Sara Pekerar ◽  
Jham Papale ◽  
Julio A. Urbina
Keyword(s):  
Trypanosoma Cruzi ◽  
Structural Parameters ◽  
Spectroscopic Characterization ◽  
Structural Parameter ◽  
Torsion Angles ◽  
Methyl Transferase ◽  
X Ray ◽  
The Family ◽  
Fused Ring ◽  
The Mean

Molecular structural parameters of two potential drugs against Trypanosoma cruzi epimastigotes, 20-piperidin-2-yl-5α-pregnan-3β,20-diol (1) and 20-N-methylpiperidin-2-yl-5α-pregnan-3β, 20-diol (2) were studied using a combination of a stereoselective synthetic route, spectroscopic characterization and single-crystal X-ray analysis. Both compounds were synthesized with an R configuration at C20. This chirality is a consequence of the stereoselectivity observed during the formation of the intermediate 20-pyridin-2-yl-5α-pregnan-3β,20R-diol (4). NMR data indicated that the six-membered aza ring of (2) is conformationally more restrained, in CDCl3 solution, than (1). X-ray studies showed that maximum deviations among structural molecular parameters of (1) and (2) correspond to torsion angles along the C20—C22 bonds, leading to a different relative orientation of the N atom; a critical structural parameter for the binding properties of aza-sterols to Δ24(25) sterol methyl transferase. Cremer–Pople parameters of the five-membered rings of (1) and (2) lie in the observed range for a family of tetracyclic fused ring systems retrieved from the CSD. The φ2 parameter of (1) lies just on the mean of the family, while φ2 of (2) deviates significantly towards the lower limit.

Synthesis, X-ray crystallography, thermogravimetric analysis and spectroscopic characterization of isostructural one-dimensional coordination polymers as sorbents for some anions

CrystEngComm ◽  
2018 ◽  
Vol 20 (13) ◽  
pp. 1783-1796 ◽  
Author(s):  
Bahram Ghanbari ◽  
Leila Shahhoseini ◽  
Agata Owczarzak ◽  
Maciej Kubicki ◽  
Reza Kia ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Coordination Polymers ◽  
Spectroscopic Characterization ◽  
One Dimensional ◽  
X Ray ◽  
X Ray Crystallography

A new series of coordination polymers capable of adsorbing anions have been synthesized by employing a dipyridine substituted diazacrown macrocycle as linker.

Synthesis, Spectroscopic Characterization, and Structure of closo-1,10-B10H8F22- and Related Fluorinated Derivatives of B10H102-

1997 ◽  
Vol 62 (8) ◽  
pp. 1310-1324 ◽  
Author(s):  
Sergei V. Ivanov ◽  
Svetlana M. Ivanova ◽  
Susie M. Miller ◽  
Oren P. Anderson ◽  
Nikolai T. Kuznetsov ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Single Crystal ◽  
Spectroscopic Characterization ◽  
X Ray ◽  
X Ray Crystallography ◽  
Fluorinated Derivatives ◽  
Derivatives Of

The treatment of salts of the B10H102- anion with the commercially available N-fluoro reagent 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (F-TEDA) resulted in the formation of fluorinated derivatives of this ten-vertex borane dianion. The effects of changing the solvent, temperature, and reagent stoichiometry were studied. The derivatives 1-B10H9F2-, 2-B10H9F2-, 1,2-B10H8F22-, 1,6-B10H8F22-, 1,10-B10H8F22-, and 1,2,10-B10H7F32- were examined by a combination of 11B and 19F NMR spectroscopy and by IR spectroscopy. The salt [Ph4P]2[1,10-B10H8F2] . 3 CH2Cl2 was structurally characterized by single-crystal X-ray crystallography: C51H48B10Cl6F2P2, monoclinic, C2/c, a = 13.8134(9), b = 19.141(1), c = 21.136(1) Å, β = 91.546(1)°, Z = 4, T = -100 °C, R = 0.077.

The geometry of 4-(1-ethoxyethylidene)-5-oxazolones and thiazolones: 1H and 13C studies and the crystal structure of 4-[(Z)-1-ethoxyethylidene]-2-phenyl-5-oxazolone

1985 ◽  
Vol 63 (12) ◽  
pp. 3618-3630 ◽  
Author(s):  
R. A. Bell ◽  
R. Faggiani ◽  
C. J. L. Lock ◽  
R. A. McLeod
Keyword(s):  
Crystal Structure ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Side Chain ◽  
Oxazole Ring ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cell Dimensions ◽  
Ring Nitrogen ◽  
E And Z Isomers

A series of E and Z isomers of substituted 4-(1-ethoxyethylidene)-5-oxazolones and thiazolones have been prepared and their 1H and 13C spectra recorded. The vinylic methyl 1H chemical shifts showed minimal differences between E and Z isomers whereas the vinylic OCH21H signals differed by 0.15–0.43 ppm, with the Z isomer being consistently the more deshielded. Both vinylic methyl and OCH2 groups showed different 13C resonances for each isomer, with the Z isomers being the more deshielded. The Z geometry was conclusively defined for one isomer of 4-(1-ethoxyethylidene)-2-phenyl-5-oxazolone, 5, by X-ray crystallography and this was sufficient to assign the geometry of the remaining pairs of E and Z isomers. Oxazolone 5 has the space group P21/n and cell dimensions a = 9.219(3), b = 19.899(5), c = 7.459(1) Å, β = 118.01(2)°, and has four formula units in the unit cell. Intensities were measured with use of MoKα radiation and a Nicolet P3 diffractometer. The crystal structure was determined by standard methods and refined to R1 = 0.0709, R2 = 0.0696 based on 1419 independent reflections. The molecule is essentially planar and most bond lengths and angles are normal. Exceptions are the very short C(olefin)—O(ether) bond (1.339(4) Å) and the large ether C—O—C angle (122.1(3)°) caused by extreme delocalization in the O(ether)CCCO(carbonyl) system. The planarity causes a number of strong intramolecular repulsive interactions, causing an exceptionally small external olefin angle, O(ether)CC(methyl), of 108.1(4)°. The ethoxyl side chain of 5 adopts a conformation in the solid state which places the methylene of the OCH2 group adjacent to the oxazole ring nitrogen. This conformation is proposed to persist in solution phases and is consistent with the observed 13C chemical shifts and known γ and δ substituent effects.

Preparation, Crystal Structure and Spectroscopic Characterization of [Ga(OH)(SO4)(terpy)(H2O)] · H2O (terpy=2,2’:6’,2-Terpyridine): The First Characterized Gallium(III) Sulfato Complex

2004 ◽  
Vol 59 (3) ◽  
pp. 291-297 ◽  
Author(s):  
Andreas Sofetis ◽  
Giannis S. Papaefstathiou ◽  
Aris Terzis ◽  
Catherine P. Raptopoulou ◽  
Theodoros F. Zafiropoulos
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Good Yield ◽  
Spectroscopic Data ◽  
Spectroscopic Characterization ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr

The reaction of Ga2(SO4)3·18H2O and excess 2,2′:6′,2″-terpyridine (terpy) in MeOH / H2O leads to [Ga(OH)(SO4)(terpy)(H2O)]·H2O (1·H2O] in good yield. The structure of the complex has been determined by single-crystal X-ray crystallography. The GaIII atom in 1·H2O is 6-coordinate and ligation is provided by one terdentate terpy molecule, one monodentate sulfate, one terminal hydroxide and one terminal H2O molecule; the coodination polyhedron about the metal is described as a distorted octahedron. There is an extensive hydrogen-bonding network in the crystal structure which generates corrugated layers parallel to bc. The new complex was characterized by IR and 1H NMR spectroscopy. The spectroscopic data are discussed in terms of the nature of bonding

scholarly journals Effect of the ruffled porphyrin ring on electronic structures: structure and characterization of [Fe(TalkylP)(OClO3)] and [Fe(TPrP)(THF)2]ClO4 (alkyl = Ethyl, Et and n-Propyl, Pr)

2013 ◽  
Vol 17 (01n02) ◽  
pp. 118-124 ◽  
Author(s):  
Ming Li ◽  
Allen G. Oliver ◽  
Teresa J. Neal ◽  
Charles E. Schulz ◽  
W. Robert Scheidt
Keyword(s):  
Electronic Structures ◽  
Structural Parameters ◽  
Structural Features ◽  
Magnetic Data ◽  
Porphyrin Ring ◽  
Magnetic Susceptibilities ◽  
X Ray ◽  
X Ray Crystallography ◽  
Intermediate Spin

We report the synthesis of Fe(TalkylP)(OClO3)] (alkyl = ethyl and propyl) and [Fe(TPrP)(THF)2]ClO4 , which are characterized by UV-vis, EPR, X-ray crystallography, and solid-state magnetic susceptibilities. The macrocycles of all three complexes are ruffled, all of the structural features for [Fe(TEtP(OClO3)] and [Fe(TPrP)(OClO3)] are characteristic of the nearly pure S = 3/2 state, while the structural parameters for [Fe(TPrP)(THF)2]ClO4 feature a pure intermediate-spin (S = 3/2) state, which are all consistent with EPR and magnetic data. It is clear from these studies that the ruffled conformation plays a significant role in affecting the extent of S = 3/2 character.

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