ChemInform Abstract: 1,5-Dilithiated Arenes (I)-(III): Double Metal Bridging Verified by Three X-Ray Structures and MNDO Calculations.

ChemInform ◽  
2010 ◽  
Vol 24 (41) ◽  
pp. no-no
Author(s):  
M. KRANZ ◽  
H. DIETRICH ◽  
W. MAHDI ◽  
G. MUELLER ◽  
F. HAMPEL ◽  
...  
Keyword(s):  
X Ray ◽  
Mndo Calculations

1,5-Dilithiated arenes: double metal bridging verified by three X-ray structures and MNDO calculations

1993 ◽  
Vol 115 (11) ◽  
pp. 4698-4704 ◽  
Author(s):  
Michael Kranz ◽  
Hans Dietrich ◽  
Waruno Mahdi ◽  
Gerhard Mueller ◽  
Frank Hampel ◽  
...  
Keyword(s):  
X Ray ◽  
Mndo Calculations

Preparation, crystal and molecular structures of Ph2CNSNSO and a comparison of the —SNSO and —SNSS chromophores

1985 ◽  
Vol 63 (5) ◽  
pp. 1063-1067 ◽  
Author(s):  
Tristram Chivers ◽  
Richard T. Oakley ◽  
Roger Pieters ◽  
John F. Richardson
Keyword(s):  
Thermal Decomposition ◽  
Molecular Structures ◽  
Structural Determination ◽  
Model Compounds ◽  
Excitation Energies ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Mndo Calculations

The sulphenyl chloride, Ph2CNSCl, prepared insitu from Ph2CNSiMe3 and sulphur dichloride, has been employed in the synthesis of Ph2CNSNSO and Ph2CNSNSNSNCPh2 by reaction with Me3SiNSO and Me3SiNSNSiMe3, respectively. An X-ray structural determination of Ph2CNSNSO shows it to consist of a planar cis-trans chain. The crystals are triclinic and belong to the space group[Formula: see text], a = 9.9078(8), b = 10.0967(9), c = 15.1682(14) Å, α = 78.646(7), β = 71.065(7), γ = 63.449(7)°, V = 1281.5(5) Å3, Z = 4. The final R and Rw values were 0.033 and 0.027, respectively. The π* → π* excitation energies for the RSNSO and RSNSS chromophores are compared for different R groups and discussed in the light of MNDO calculations on the model compounds HSNSX (X = S, O). The thermal decomposition of both Ph2CNSNSO and Ph2CNSNSNSNCPh2 produced S4N4 and Ph2CO or (Ph2CN)2S, respectively.

The X-ray structure and MNDO calculations of α-terthienyl: A model for polythiophenes

1989 ◽  
Vol 30 (3) ◽  
pp. 381-389 ◽  
Author(s):  
F. Van Bolhuis ◽  
Hans Wynberg ◽  
E.E. Havinga ◽  
E.W. Meijer ◽  
Emiel G.J. Staring
Keyword(s):  
X Ray ◽  
Mndo Calculations

Synthese und Kristallstruktur von Iodmethyltriphenylphosphonium-iodid (C6H5)3PCH2I+I- / Synthesis and Crystal Structure of Iodomethyltriphenylphosphonium Iodide (C6H5)3PCH2I+I-

1993 ◽  
Vol 48 (12) ◽  
pp. 1760-1766 ◽  
Author(s):  
H. Vogt ◽  
K. Lauritsen ◽  
L. Riesel ◽  
M. von Löwis ◽  
G. Reck
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Colourless Needle ◽  
Molecular Structures ◽  
Orthorhombic Space Group ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Mndo Calculations ◽  
Good Agreement

Iodomethyltriphenylphosphonium iodide, (C6H5)3PCH2I+I-, has been prepared by the reaction of (C6H5)3P with CH2I2 in dichloromethane forming colourless needle like crystals. The crystal and molecular structures have been determined by an X-ray structure analysis. The crystals are orthorhombic, space group Pca21, Z = 8; a = 1478,8(3) pm, b = 1249,3(3) pm, c = 2053,2(3) pm. R = 0.050 for 3219 observed reflections with I ≥ 2 σ(Ι). In the solid state the title compound exists as two discrete monomeric units, (C6H5)3PCH2I+I-. In both symmetry independent units the I-I distances are surprisingly short with 346,5(1) pm and 356,3(1) pm. For the title compound the results of AM 1, PM 3, and MNDO calculations are in good agreement with corresponding values determined by the X-ray analysis.

Synthese und Kristallstruktur des Bromdifluormethyl-triphenyl- phosphoniumbromids, [(C6H5)3PCF2Br]+ Br- / Synthesis and Crystal Structure of Bromodifluoromethyl-triphenylphosphonium Bromide, [(C6H5)3PCF2Br]+ Br-

2000 ◽  
Vol 55 (2) ◽  
pp. 167-170 ◽  
Author(s):  
C. Bender ◽  
D. Wulff-Molder ◽  
H. Vogt ◽  
F. Ritschl ◽  
M. Meisel
Keyword(s):  
Crystal Structure ◽  
Chloride Solution ◽  
Methylene Chloride ◽  
Monoclinic Space Group ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Methylene Chloride Solution ◽  
Mndo Calculations ◽  
Triphenylphosphonium Bromide ◽  
Good Agreement

Abstract Difluorobromomethyl-triphenylphosphonium bromide [(C6H5)3PCF2Br]+ Br- (1) has been prepared by the reaction of triphenylphosphine with dibromodifluoro-methane in acetonitrile or methylene chloride. The colorless crystals are monoclinic, space group P 21/n, Z=4, a = 1067.1(2), b = 1488,5(2), c = 1178,2(2) pm, β = 95,67(3)°. The lattice contains Br- anions and [(C6H5)3PCF2Br]+ cations with a Br-Br distance of 322,33(11) pm.. For the title compound the results of AM 1, PM 3 ,and MNDO calculations are in good agreement with corresponding values determined by the X-ray analysis only in the case of PM 3.The yellow-red [(C6H5)3PCF2Br]+ Br3- (2) has been obtained by treating 1 with equimolar quantities of elemental bromine in methylene chloride solution.

Stereochemistry of 2,6-Dipyridine Substituted N-Benzyl-4-piperidone Mono- and Dicarboxylates and of the Corresponding Reduction Products

1989 ◽  
Vol 44 (5) ◽  
pp. 565-574 ◽  
Author(s):  
U. Holzgrabe ◽  
B. Piening ◽  
K.-F. Hesse ◽  
H.-D. Höltje ◽  
M. Worch
Keyword(s):  
Sodium Borohydride ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Nmr Data ◽  
Mndo Calculations ◽  
C Nmr

The alkyl N-benzyl-4-piperidone-3-carboxylate (1) is synthesized by a Mannich procedure from pyridine aldehyde, benzylamine and the monoester of acetonedicarboxylate; the corresponding diester 2 is formed by condensation of pyridine aldehyde, benzylamine and dimethyl 3-oxoglutarate. Isomerism is observed with respect to keto-enol tautomerism and cis or trans substitution of the pyridines. The structure of the enol lb (C24H23N3O3) is determined by X-ray analysis: it crystallizes in the triclinic space group P 1̄ with a = 9.965(2), b = 10.476(2), c = 10.838(2) Å, α = 69.48(1), β/3 = 81.56(1), γ = 79.09(1)°, Ζ = 2 and Dx = 1.29 g cm-3. It is refined to R(unweighted) = 0.047 and R(weighted) = 0.045 using 1459 non-equivalent reflections. The structures of la/b and 2a/b were determined by 1H and 13C NMR data. MNDO calculations of 1a/b are discussed. The enols 1/2b are reduced by sodium borohydride. The configuration of the obtained alcohols is determined by NMR data.

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