The Competition for Electrons:  Aromatic Stabilization in a Six-Membered Ring vs Cyclobutadiene−Iron Complex. The Molecular Structure of Tris(tricarbonylironcyclobutadieno)benzene

1998 ◽  
Vol 63 (2) ◽  
pp. 247-253 ◽  
Author(s):  
Amnon Stanger ◽  
Nissan Ashkenazi ◽  
Roland Boese
Keyword(s):  
Molecular Structure ◽  
Iron Complex ◽  
Membered Ring ◽  
Aromatic Stabilization

The Crystal and Molecular Structure of sym-fac-(1,4,7-Triazaheptane)-(S)-aspartatocobalt(III) Diperchlorate Dihydrate

1994 ◽  
Vol 59 (5) ◽  
pp. 1052-1058 ◽  
Author(s):  
Jan Ondráček ◽  
Jana Ondráčková ◽  
Jaroslav Maixner ◽  
František Jursík
Keyword(s):  
Molecular Structure ◽  
Aspartic Acid ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Membered Ring ◽  
Boat Conformation ◽  
Hydrogen Atoms ◽  
Orthorhombic System ◽  
Anisotropic Temperature ◽  
Heavy Atom Method

The crystal and molecular structure of s-fac-[Co((S)-Asp)(dien)]ClO4 . HClO4 .2 H2O (dien = 1,4,7-triazaheptane) was solved by the heavy atom method. The position parameters of the non-hydrogen atoms and their anisotropic temperature parameters were refined based on 1 726 observed reflections with a final value of R = 0.073. The substance crystallizes in the orthorhombic system in the space group P212121, Z = 4, a = 8.506(1), b = 17.171(2), c = 13.277(1) Å. The structure involves hydrogen bonds between the O2, O4 and HN2 atoms of aspartic acid and the two molecules of water. The five-membered dien chelate rings take the asymmetric envelope conformations. The five-membered ring of (S)-aspartic acid possesses the symmetric envelope conformation whereas the six-membered ring exhibits the skew boat conformation.

N-ACYL SUBSTITUTED PHENYLHYDROXYLAMINES: THE EFFECT OF RADICAL CHANGE ON ANALYTICAL BEHAVIOR

1957 ◽  
Vol 35 (12) ◽  
pp. 1454-1460 ◽  
Author(s):  
C. A. Armour ◽  
D. E. Ryan
Keyword(s):  
Aqueous Solution ◽  
Stability Constant ◽  
Radical Change ◽  
Spectrophotometric Study ◽  
Iron Complex ◽  
Membered Ring ◽  
Analytical Reagents ◽  
Colorimetric Reagent ◽  
Analytical Behavior

The synthesis of a number of N-acyl substituted phenylhydroxylamines is outlined and the effect of the change in the nature of the acyl group on their usefulness as analytical reagents is described. Stability constant measurements in alcohol show an increase in stability with an increase in basicity of reagent regardless of the nature of the attached group; their ability to precipitate complexes from aqueous solution, however, is markedly dependent on the nature of the attached radical. A spectrophotometric study shows the existence of both a 1:1 and a 1:3 iron complex. A more sensitive colorimetric reagent results with an unsaturated five-membered ring as the attached grouping.

The Molecular Structure of 2-Methyloxacyclobutane, as Studied by Electron Diffraction

1979 ◽  
Vol 34 (9) ◽  
pp. 1130-1134 ◽  
Author(s):  
György Schultz ◽  
Mihály Bartók
Keyword(s):  
Molecular Structure ◽  
Carbon Atom ◽  
Electron Diffraction ◽  
Electron Diffraction Study ◽  
Membered Ring ◽  
Torsional Angle ◽  
Planar Conformation ◽  
The Mean ◽  
Nozzle Temperature ◽  
Endocyclic Bond

Abstract A gas electron diffraction study of 2-methyloxacyclobutane has been carried out at room nozzle temperature. The four membered ring takes a planar conformation. The mean ra values for the O-C, C-C and C-H bonds are 1.448(5)A, 1.534(4)A and 1.118(3) Å, respectively. The endocyclic bond angles are C-C-C = 85.5(18)° and C-C-O=91.2 (15)°, while the angle C-O-C was assumed to be 92°. The position of exocyclic carbon atom was characterized, in addition by < Cexocyclic-C-O = 110.7(7)° and torsional angle Cexocyclic-C-O-C = 59.6(40)° (0° corresponds to the anti position of Cexocyclic-C and O-C bonds).

scholarly journals New Spiro-Tin Compounds: Reaction of N,N′-Dialkyl Sulfur Diimides with Cyclic Bis(amino)stannylenes - Unexpected Formation of a N-N Bond

1995 ◽  
Vol 50 (12) ◽  
pp. 1811-1817 ◽  
Author(s):  
Max Herberhold ◽  
Christian Köhler ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer
Keyword(s):  
Molecular Structure ◽  
Magnetic Resonance ◽  
Single Crystal ◽  
Structure Analysis ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
Unexpected Formation ◽  
Tin Compounds ◽  
X Ray ◽  
Tert Butyl

N,N′-Dialkyl sulfur diimides (1), R(NSN)R [R = Me (a), Et (b), nPr (c), nBu (d)] react with cyclic bis(amino)stannylenes such as 1,3-di-tert-butyl-4,4-dimethyl-1,3,4,2λ2-diazasilastannetedine (2) or 1,3-di-tert-butyl-4,4,5,5-tetramethyl-1,3,4,5,2λ2-diazadisilastannolidine (3) in a 2:1 ratio to give the new spiro-tin(IV) compounds 5a-d, 6b and 6c, built from the respective cyclic bis(amino)stannylene and a seven-membered ring in which the two sulfur diimide groups are coupled via a N-N bond and across the tin atom. A 1:1 adduct 4 is proposed as an intermediate which is the final product 4e in the case of R = tBu (1e). The products were characterized by multinuclear magnetic resonance (1H, 13C, 15N, 29Si, 119Sn NMR), and in the case of 5c the molecular structure was determined by single crystal X-ray structure analysis [monoclinic, space group C2/c ; a = 1504.1(3), b = 1393.3(3), c = 1688.6(3) pm; β = 115.71(3)°].

Reaktion von N-Trimethylsilyl-N′(N″ -trimethylsilylammodiphenylphosphoranylidenimino) sulfamid mit Wolframoxitetrachlorid und die Struktur von (Cl3WNPPh2N)2 Reaction of N-Trimethylsilyl-N′(N″ -trimethylsilylaminodiphenylphosphoranylidene)sulfamide with Tungstenoxitetrachloride and the Structure of (Cl3WNPPh2N)2

1992 ◽  
Vol 47 (2) ◽  
pp. 171-174 ◽  
Author(s):  
H. W. Roesky ◽  
T. Raubold ◽  
M. Noltemeyer ◽  
M. Witt ◽  
R. Bohra
Keyword(s):  
Molecular Structure ◽  
Structure Analysis ◽  
Ring System ◽  
Membered Ring ◽  
X Ray

1The reaction of ClSO2N = PPh2Cl () with NH3 yields H2NSO2N = PPh2NH2 (2).This compound is converted to Me3Si(H)NSO2N = PPh2N(H)SiMe3 (3) by Me3SiNMe2. 3 reacts with WOCl4 under elimination of (Me3Si)2O and ClSO2NH2 to yield the eight-membered ring system (Cl3WNPPh2N)2 (4).The molecular structure of 4 was investigated by an X-ray structure analysis.

ChemInform Abstract: Reaction of Bis(2-mercaptoethyl)phosphines with Organotin Compounds. Molecular Structure of a Tin Containing Sixteen-Membered Ring.

ChemInform ◽  
1988 ◽  
Vol 19 (20) ◽  
Author(s):  
K. JURKSCHAT ◽  
W. UHLIG ◽  
C. MUEGGE ◽  
A. TZSCHACH ◽  
B. SCHMIDT ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Membered Ring ◽  
Organotin Compounds
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