2-Stannylpyridine-Borane Adducts - Multinuclear Magnetic Resonance Study and X-Ray Structure Determination of a 1,4-Dihydro-4 a,1,4-azastannabora-naphthalene Derivative

1995 ◽  
Vol 50 (5) ◽  
pp. 809-815 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Heidi E. Maisel
Keyword(s):  
Solid State ◽  
Lone Pair ◽  
Molecular Structures ◽  
Coupling Constants ◽  
Hydrogen Atoms ◽  
Naphthalene Derivative ◽  
X Ray ◽  
Cp Mas Nmr ◽  
Solution Changes

Abstract The adduct formation between 2-trimethylstannyl-pyridine (1) and triethylborane, leading to 2a, and 9-borabicyclo[3.3.1]nonane, leading to 2b, was studied by 1H, 11B, 13C, 15N and 119Sn NMR in solution. Changes in the magnitude of the coupling constants J(119Sn, 13C), with respect to the data for I, were analysed. The absolute signs have been determined [all coupling constants nJ(119SnZ3C) to methyl and pyridine carbon atoms in 1 to 3 possess a negative sign and the same is true for nJ(119Sn,1H) of the pyridine hydrogen atoms] by various two-dimensional NMR experiments, and attributed to the influence of the lone pair of electrons at the nitrogen atom in 1. The NMR spectroscopic results for the 1,4-dihydro- 4a,1,4-azastannabora-naphthalene derivative 3, in which structural fragments are present analogous to those in the borane adducts 2, correspond to those for 1 and 2a,b. The molecu­lar structure of 3 has been determined by X-ray analysis [orthorhombic; P212121, a = 713.9(2), b - 1566.0(2), c = 1578.4(2) pm]. Solid-state 13C and 119Sn CP/MAS NMR spectra prove that the molecular structures of 3 in the solid state and in solution are very similar.

NMR Spectroscopy of Tetra(propyn- 1-yl)silane in the Solid State and in Solution

2003 ◽  
Vol 58 (8) ◽  
pp. 809-812 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Oleg L. Tok ◽  
Amin Badshah
Keyword(s):  
Solid State ◽  
Bulk Material ◽  
Point Group ◽  
Coupling Constants ◽  
Data Set ◽  
Tin Compounds ◽  
X Ray ◽  
Nmr Data ◽  
Solid State Structures

The crystal structure of tetra(propyn-1-yl)silane, Si(C≡CMe)4 1, has revealed a completely asymmetric molecule (point group C1). Since this finding concerns a single crystal, the bulk material of 1 was studied by solid-state 29Si and 13C MAS NMR. This confirmed the result of the X-ray analysis, and by comparison with previous NMR measurements of the tin analogue 1(Sn) it is concluded that 1 and 1(Sn) must have very similar solid-state structures which are in contrast to those known for other tetra(alkyn-1-yl)silicon and -tin compounds. The NMR data set of 1 in solution was completed by determination of the magnitude of coupling constants 1J(13C,13C).

scholarly journals Synthesis of N-Silylated Diaminosulfanes from Functionally Substituted Sulfur Diimides and Hexachlorodisilane and Octachlorotrisilane-Multinuclear Magnetic Resonance Studies and X-Ray Structure Determination of a Non-Cyclic Diaminosulfane

1993 ◽  
Vol 48 (3) ◽  
pp. 249-257 ◽  
Author(s):  
Max Herberhold ◽  
Silke Gerstmann ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Magnetic Resonance ◽  
Functional Groups ◽  
Structure Determination ◽  
Quantitative Yield ◽  
Magnetic Resonance Studies ◽  
X Ray ◽  
Cp Mas Nmr

Sulfur diimides R1(NSN)R2 (1) with different substituents R1 and/or R2 or with functional groups react with hexachlorodisilane (2) or octachlorotrisilane (3) to give the corresponding diaminosulfanes (4, 5) in quantitative yield. The formation of cyclic intermediates prior to the redox process is discussed. The products have been characterized by 1H, 13C, 15N and 29Si NMR in solution as well as by 15N and 29Si CP/MAS NMR in the solid state (4a, 4f). The crystal structure of ClMe2Si(Cl3Si)NSN(SiCl3)SiMe2Cl (4f) has been determined: space group PĪ (no. 2) with a = 864.2(2), b = 1096.8(2), c = 1232.7(2) pm and Z = 2.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

Experimental and computational structural study of two hindered aminoanthraquinones in crystals and solutions

2000 ◽  
Vol 215 (9) ◽  
Author(s):  
A.V. Yatsenko ◽  
K.A. Paseshnichenko ◽  
S.I. Popov
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Electronic Spectra ◽  
Molecular Structures ◽  
Amino Group ◽  
Single Crystal Diffraction ◽  
Molecular Conformations ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Visible Spectra

The crystal and molecular structures of 2-methyl-1-methylamino-anthraquinone (I) and 1-methylphenylamino-anthraquinone (II) were studied by the X-ray single-crystal diffraction and the visible spectra of crystalline specimens and their solutions were recorded. The molecule I is closely planar, whereas in the molecule II the amino group is 58° rotated out of the plane of the anthraquinone skeleton. In both structures the molecules pack in stacks. The comparison of experimental and calculated (on the DFT and AM1 levels) molecular structures, together with the comparison of experimental and INDO/S-calculated electronic spectra, give the evidence that molecular conformations (especially for II) change upon transfer from the solid state to solutions, and the π-delocalisation throughout the whole molecule enhances in the solid state.

On the nature of M–CO(lone pair)⋯π(arene) interactions in the solid state of fluorinated oxaphosphirane complexes

CrystEngComm ◽  
2015 ◽  
Vol 17 (35) ◽  
pp. 6736-6743 ◽  
Author(s):  
Cristina Murcia-García ◽  
Antonio Bauzá ◽  
Antonio Frontera ◽  
Rainer Streubel
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Lone Pair ◽  
X Ray ◽  
High Level

The X-ray structures of several oxaphosphirane tungsten(0) complexes exhibit interesting intramolecular W–CO(lone pair)ċπ(arene) interactions that have been rationalized by means of high-level DFT calculations and the CSD.

Structural Properties of a Dimeric Phenylcyanamidocopper(I) Complex, [{Cu(PPh3)2(C6H5NCN)}2]

2000 ◽  
Vol 53 (12) ◽  
pp. 971 ◽  
Author(s):  
Eric W. Ainscough ◽  
Andrew M. Brodie ◽  
Peter C. Healy ◽  
Joyce M. Waters
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Structural Properties ◽  
Structure Determination ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
X Ray ◽  
Angle Spinning

The X-ray crystal structure determination of bis[-(phenylcyanamido)bis(triphenylphosphine)copper(I)], [{Cu(PPh3)2(C6H5NCN)}2], (1) is reported. The complex has a centrosymmetric dimeric structure with the phenylcyanamide ligands bridging the copper atoms in a -1,3-fashion. The structure is compared with that of the 4-methylphenylcyanamido complex, [{Cu(PPh3)2(4-MeC6H4NCN)}2] (2), and the differences observed in the Cu–P bond lengths compared with changes in the solid state 31P cross-polarization magic-angle spinning (CPMAS) spectra of the two complexes.

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