Formation of organosilicon compounds 117:1 C-brominated 1,3,5-trisilacyclohexanes and their reactions with BuLi

2000 ◽  
Vol 78 (11) ◽  
pp. 1388-1395 ◽  
Author(s):  
G Fritz ◽  
M Keuthen ◽  
F Kirschner ◽  
E Matern ◽  
H Goesmann ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Molecular Structures ◽  
Ring Closure ◽  
Organosilicon Compounds ◽  
Structure Investigation ◽  
X Ray ◽  
Nmr Data ◽  
High Yields ◽  
Subsequent Substitution ◽  
Preparative Route

The photobromination of 1,1,3,3,5,5-hexamethyl-1,3,5-trisilacyclohexane (1) almost exclusively attacks CH2 groups and results in 2,2-dibromo-trisilacyclohexane (2) as well as 2,2,4,4-tetrabromo-trisilacyclohexane (3) in high yields. Starting from a mixture of C-brominated trisilacyclohexanes the isomeric 2,2,9-tribromo-1,3,3,5,5,8,8,10,10,13,13-undecamethyl-1,3,5,8,10,13-hexasilabicyclo[7.2.2]tridec-6-yne (6) had been obtained in very low yield in an attempt to establish a preparative route to adamantanes with a C4Si6 skeleton, i.e., with C bridgeheads and SiR2 bridges. By ICl-cleavage of a Si—methyl bond in 2 and subsequent substitution with Br3CLi, the trisilacyclohexane 4 with functional groups in opposite positions of the ring can be obtained. Linking the step-by-step synthesized Cl-Me2Si-C=C-SiMe2-CH2-SiMe2-Ph to the CBr3 group of 4 results after HBr-cleavage of the Si—Ph bond in (ω-bromo-octynyl)-trisilacyclohexane (12). A ring closure of 12 would result in an isomeric hexasila bicyclo[7.2.2]tridec-6-yne. The compounds were characterized by 1H, 13C, and 29Si NMR spectra. Additionally, the molecular structures of 4 and 6 were confirmed by X-ray single crystal investigations.Key words: 1,1,3,3,5,5-hexamethyl-1,3,5-trisilacyclohexane, bromination, 2,2,9-tribromo-1,3,3,5,5,8,8,10,10,13,13-undecamethyl-1,3,5,8,10,13-hexasilabicyclo[7.2.2]tridec-6-yne, carbosilane synthesis, NMR data, crystal structure investigation.

scholarly journals Silylated gallium and indium chalcogenide ring systems as potential precursors to ME (E=O, S) materials

2013 ◽  
Vol 11 (7) ◽  
pp. 1225-1238
Author(s):  
Iliana Medina-Ramírez ◽  
Cynthia Floyd ◽  
Joel Mague ◽  
Mark Fink
Keyword(s):  
Thermal Decomposition ◽  
Room Temperature ◽  
Membered Ring ◽  
Molecular Structures ◽  
Nmr Studies ◽  
X Ray ◽  
X Ray Crystallography ◽  
High Yields ◽  
Vt Nmr ◽  
State 1

AbstractThe reaction of R3M (M=Ga, In) with HESiR′3 (E=O, S; R′3=Ph3, iPr3, Et3, tBuMe2) leads to the formation of (Me2GaOSiPh3)2(1); (Me2GaOSitBuMe2)2(2); (Me2GaOSiEt3)2(3); (Me2InOSiPh3)2(4); (Me2InOSitBuMe2)2(5); (Me2InOSiEt3)2(6); (Me2GaSSiPh3)2(7); (Et2GaSSiPh3)2(8); (Me2GaSSiiPr3)2(9); (Et2GaSSiiPr3)2(10); (Me2InSSiPh3)3(11); (Me2InSSiiPr3)n(12), in high yields at room temperature. The compounds have been characterized by multinuclear NMR and in most cases by X-ray crystallography. The molecular structures of (1), (4), (7) and (8) have been determined. Compounds (3), (6) and (10) are liquids at room temperature. In the solid state, (1), (4), (7) and (9) are dimers with central core of the dimer being composed of a M2E2 four-membered ring. VT-NMR studies of (7) show facile redistribution between four- and six-membered rings in solution. The thermal decomposition of (1)–(12) was examined by TGA and range from 200 to 350°C. Bulk pyrolysis of (1) and (2) led to the formation of Ga2O3; (4) and (5) In metal; (7)–(10) GaS and (11)–(12) InS powders, respectively.

1,2-Di(silyl)benzene and 1,4-Dibromo-2,5-di(silyl)benzene

1994 ◽  
Vol 49 (8) ◽  
pp. 1036-1040 ◽  
Author(s):  
Robert Schröck ◽  
Alexander Sladek ◽  
Hubert Schmidbaur
Keyword(s):  
Methanesulfonic Acid ◽  
Intermediate Compound ◽  
Molecular Structures ◽  
High Yield ◽  
Electronic Effects ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Yields ◽  
Experimental Findings ◽  
Silylation Reaction

1,2-Di(silyl)benzene (3), has been prepared in a three-step process starting with the reac­tion of 1,2-dibromobenzene and p-tolyl(chloro)silane with magnesium in tetrahydrofuran. which affords 1,2-bis(p-tolylsilyl)benzene (1) as a stable high-yield intermediate. Compound 1 has been converted into 1,2-bis(trifluoromethanesulfonatosilyl)benzene (2) with trifluoro- methanesulfonic acid, and finally into 3 by reduction with lithiumaluminiumhydride, both again in high yields. - In an attempt to prepare 1,2,4,5-tetra(silyl)benzene in an analogous way. only the bis-silylated species could be obtained (from 1,2,4,5-C6H2Br4. p-MeC6H4SiClH2 and Mg powder: 1,4-dibromo-2,5-bis(p-tolylsilyl)benzene. 4, and 1,4-dibromo-2,5-di(silyl)- benzene, 6, via 1,4-dibromo-2,5-bis(trifluoromethanesulfonatosilyl)benzene, 5). The crystal structures of compounds 4 and 6 have been determined by X-ray diffraction. The results indicate no steric hindrance in these molecules and it is thus not obvious from the molecular structures why the silylation reaction does not proceed any further to give the tetrasilylated benzene derivatives. Electronic effects have to be invoked to rationalize the experimental findings.

Spectroscopic and X-Ray Investigation of Cobalt(III) Complexes with 2-Oximinocarboxylic Acids

1993 ◽  
Vol 48 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Rostislav D. Lampeka ◽  
Zamira D. Uzakbergenova ◽  
Victor V. Skopenko
Keyword(s):  
Electronic Absorption Spectra ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Octahedral Structure ◽  
Space Group ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
R Factors

Mixed complexes of Co(III) with 2-oximinopropionic (H2A) or 2-oximino-3-phenylpropionic (H2B) acid and different amine (imidazole, benzimidazole, pyridine, β-picoline, γ-picoline) are reported. Characterization of the complexes was based upon elemental analysis, conductivity and JR, 1H NMR, and electronic absorption spectra, and X-ray diffraction analysis. The organic ligands behave as O,N donors via the carboxyl oxygen and the oxime nitrogen atoms. A trans-octahedral structure has been assigned to the bis(2-oximinocarboxylato)bis(amine)cobalt(III) on the basis of 1H NMR data.The crystal and molecular structures of the complexes trans-[bis(2-oximinopropionato)bis-(imidazole)]- (I) and trans-[bis(2-oximinopropionato)bis(pyridine)]cobalt(III) (II) were determined. I crystallizes in space group P2/n with a = 14.1 67(2), b = 8.774(1), c = 14.785(2) Å,β = 113.37(1)°, Z = 4, Dcalc = 1.568 g · cm-3. II crystallizes in space group P1̄ with a = 9.122(2), b = 10.038(2), c = 11.759(2) Å, α = 69.95(1)°, β = 67.47(2)°, γ = 69.49(2)°, Ζ = 2, Dcalc = 1.547 g cm-3. The structures were refined to unweighted R factors of 0.036 and 0.028, respectively. The coordination sphere around Co is pseudo-octahedral with the 2-oximinopropionato ligands occupying four equatorial positions, and the amines in axial positions.

Cyclo-thiazenokomplexe von Vanadium(V) Die Kristallstruktur von (AsPh4)2[V(N3)3(N3S2)]2 · CH2Cl2 / Cyclo-thiazeno Complexes of Vanadium(V) The Crystal Structure of (AsPh4)2[V(N3)3(N3S2)]2 · CH2Cl2

1984 ◽  
Vol 39 (12) ◽  
pp. 1686-1695 ◽  
Author(s):  
Jürgen Hanich ◽  
Magda Krestel ◽  
Ulrich Müller ◽  
Kurt Dehnicke ◽  
Dieter Rehder
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Nmr Spectra ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Nmr Data ◽  
Donor Acceptor

An improved synthesis for [VCl2(N3S2)]∞, was found in the reaction of VOCl3 with (NSCl)3; when the reaction is performed in H2CCl2 and (NSCl)3 is used in excess, the thiazyl-solvate [VCl2(N3S2) · NSCl]2 is obtained. [VCl2(N3S2)] reacts with AsPh4Cl to form (AsPh4)2[VCl3(N 3S2)]2; this reacts with AgN3 in CH2Cl2 suspension to yield (AsPh4)2[V (N3)3(N3S2)]2 · CH2Cl2. The compounds were characterized by their IR and 51V NMR spectra. The latter are compared with new 51V NMR data for [VO2Cl2]⊖ and [VOCl4]⊖ ; a decrease of 51V shielding in the order [VO2Cl2]⊖ > [VOCl4]⊖ > [VX3(N3S2)]22⊖ (X - N3 > Cl) is found, which is interpreted in terms of increasing polarizability of the ligands and of ring contributions to the extreme deshielding observed with the thiazenovanadates.The crystal structure of (AsPh4)2[V(N3)3(N3S2)]2 · CH2Cl2 was determined from X-ray diffraction data (1496 observed reflexions, R = 0.058). It crystallizes in the triclinic space group P 1̄ with one formula unit per unit cell and with the lattice constants a - 1087, b = 1317, c = 1350 pm, α = 58.8, β = 85.9, γ = 68.0°. The structure consists of AsPh4⊕ ions, CH2Cl2 molecules and centrosymmetric [V(N3)3(N3S2)]22⊖ anions. In the latter. N3S2 ligands are bonded to the V atoms in a chelate manner with short V = N bonds (189 and 172 pm) forming planar VN3S2 rings. The dimerization is accomplished by V -N donor-acceptor interactions (224 pm) involving one N atom of each VN3S2 ring. The vanadium coordination number of 6 is com pleted by three azido groups with V -N bond distances of 200 to 204 pm.

Tetra(alkynyl)silanes, a 3,6-Disila-triyne, a 3,6,9-Trisila-tetrayne, a 1,3,4,6-Tetrasiladiyne, and Bis(trimethylstannyl)ethyne. Molecular Structures and Solid-state NMR Studies

2010 ◽  
Vol 65 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Ezzat Khan ◽  
Amin Badshah ◽  
Elias Molla ◽  
Peter Thoma ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Mas Nmr ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
Solution State ◽  
Nmr Data

The molecular structures of three alkynylsilanes, tetrakis(ethynyl-p-tolyl)silane, 3,3,6,6,-tetramethyl- 3,6-disila-triyne, 3,3,6,6,9,9,-hexamethyl-3,6,9-trisila-tetrayne, and of bis(trimethylstannyl)- ethyne have been determined by X-ray diffraction. The same alkynylsilanes, and in addition 1,2- bis(trimethylsilylethynyl)-1,1,2,2-tetramethyldisliane, were studied by solid-state 13C and 29Si MAS NMR spectroscopy. The results of these measurements were compared with crystallographic evidence and also with relevant solution-state NMR data.

Structure of a pentacyclic triterpenyl angelate from Loeseliamexicana. 1H 2D-NMR data and stereochemistry

1989 ◽  
Vol 67 (12) ◽  
pp. 2071-2077 ◽  
Author(s):  
M. Jiménez E. ◽  
K. Velézquez ◽  
A. Lira-Rocha ◽  
A. Ortega ◽  
E. Díaz ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Parent Compound ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
Pentacyclic Triterpene ◽  
Nmr Structure Determination ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Unambiguous Assignment

The total assignment of 1H NMR spectra of a pentacyclic triterpene from Loeseliamexicana was performed using selected 2D-NMR experiments (COSY, NOE). X-ray diffraction data were obtained from the parent compound as supplemental information to the NMR investigations. The data allowed for the unambiguous assignment of the structure and the stereochemistry of the title compound. Keywords: pentacyclic triterpene NMR, 2D NMR of terpenes, X-ray of triterpenes, triterpenyl angelate NMR, X-ray -2D NMR structure determination.

Synthesis and molecular structures of N,N-dialkyl-4-nitrosoaniline adducts of formally d6 metalloporphyrins of ruthenium and cobalt

2001 ◽  
Vol 05 (09) ◽  
pp. 702-707 ◽  
Author(s):  
LI CHEN ◽  
JESSE B. FOX ◽  
GEUN-BAE YI ◽  
MASOOD A. KHAN ◽  
GEORGE B. RICHTER-ADDO
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Molecular Structures ◽  
Spectroscopic Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
High Yields ◽  
Solid State Structures

Para-aminosubstituted nitrosoarenes react with Ru ( CO )( OEP ) or [ Co ( TPP )( THF )2] SbF 6 (OEP2- = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion, TPP2- = 5,10,15,20-tetraphenylporphyrinato dianion) to generate Ru ( OEP )( ONC 6 H 4 NMe 2)2 and [ Co ( TPP )( ONC 6 H 4 NR 2)2] SbF 6 ( R = Me , Et ), respectively, in fair to high yields. These N -bound nitrosoarene complexes have been characterized by spectroscopic methods. The complexes Ru ( OEP )( ONC 6 H 4 NMe 2)2 and [ Co ( TPP )( ONC 6 H 4 NMe 2)2] ClO 4 have also been characterized by single-crystal X-ray crystallography. Their structures represent the first reported solid-state structures of Ru and Co porphyrins containing C-nitroso ligands.

Synthesis and characterization of N-silylated, C1-symmetric benzamidinates of lithium, sodium, and tin(II)

2006 ◽  
Vol 84 (2) ◽  
pp. 269-276 ◽  
Author(s):  
Floria Antolini ◽  
Peter B Hitchcock ◽  
Alexei V Khvostov ◽  
Michael F Lappert
Keyword(s):  
Nmr Spectra ◽  
Alkali Metals ◽  
Membered Ring ◽  
Molecular Structures ◽  
Synthesis And Characterization ◽  
Neutral Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ligand Free

The synthesis and characterization of complexes obtained from the reactions between Li[N-t-Bu(SiMe3)] (A) or the sodium analogue Na[N-t-Bu(SiMe3)] (B) and the cyanoarene RCN (R = Ph or 4-MeOC6H4) are discussed. These are the THF adduct [Li{µ-cis-N(t-Bu)C(Ph)N(SiMe3)}(THF)]2 (1), the TMEDA adduct Li[N(t-Bu)C(Ph)N(SiMe3)](TMEDA) (2), the neutral ligand-free lithium benzamidinate Li[N(t-Bu)C(C6H4OMe-4)N(SiMe3)] (3), and the THF adduct Li[N(t-Bu)C(C6H4OMe-4)N(SiMe3)](THF) (3a). The preparation and structure of the crystalline compound [Na{µ-cis-N(t-Bu)C(Ph)N(SiMe3)}(OEt2)]2 (4) is described. From the lithium benzamidinate 1 and Sn(II) chloride the tin(II) complex [Sn{N(t-Bu)C(Ph)N(SiMe3)}2] (5) was obtained. The molecular structures of the crystalline compounds 1, 4, and 5 were established by X-ray diffraction. In 1 and 4 the benzamidinato ligand is both chelating and bridging, with the Me3Si-substituted nitrogen atom as the bridging site. The central planar (MN)2 four-membered ring is a rhombus in 1, with almost equal Li—N bond lengths, whereas in 4 the bonds to Na(1) are significantly longer than those to Na(2). In 5, the ligand is N,N′-chelating. Key words: alkali metals, tin(II), benzamidinates, NMR spectra, X-ray structures.

A Structural Study on Indium Tris-thiocarbamates

1994 ◽  
Vol 49 (2) ◽  
pp. 193-198 ◽  
Author(s):  
S. Bhattacharya ◽  
Miss Neena Seth ◽  
V. D. Gupta ◽  
H. Nöth ◽  
M. Thomann
Keyword(s):  
Structural Study ◽  
Nmr Spectra ◽  
Variable Temperature ◽  
Point Group ◽  
Molecular Structures ◽  
X Ray ◽  
H Nmr ◽  
Group D

Indium tris(thiocarbamates) In(S2CNiPr2)3 (1), In(SOCNiPr2)3 (2) and In(S2CNC4H4)3 (3) have been synthesized and characterized. Variable temperature 1H NMR spectra of 1 and 2 are reported. The X-ray molecular structures of 1 and 3 are found to be quite similar; the symmetry of the In(S2C)3 unit in 3 is close to point group D3 with small asymmetry in the In-S bonds.

Spectroscopic studies of triphenyltin azide and of its adducts with O- and N-donor ligands; the crystal and molecular structures of triphenyltin azide and of azido(hexamethylphosphoramide)triphenyltin(IV)

1998 ◽  
Vol 76 (12) ◽  
pp. 1827-1835 ◽  
Author(s):  
Ivor Wharf ◽  
Ryszard Wojtowski ◽  
Carol Bowes ◽  
Anne-Marie Lebuis ◽  
Mario Onyszchuk
Keyword(s):  
Solid State ◽  
Spectroscopic Studies ◽  
Triphenylphosphine Oxide ◽  
Molecular Structures ◽  
The Other ◽  
Donor Ligands ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Nmr Data ◽  
Ir And Raman

Complete far-IR and Raman data (<400 cm-1) are reported for triphenyltin azide (1) as well as for adducts Ph3SnN3·L (L = hexamethylphosphoramide (HMPA), triphenylphosphine oxide, pyridine-N-oxide, 4-picoline-N-oxide, or pyridine). The small changes in v(Sn-N3) noted on going from (1) to the adducts, as well as solid-state 119Sn nmr data, indicate that (1), like the adducts, has five-coordinate tin atoms. X-ray analysis shows that (1) crystallizes with two different chains of five-coordinate Ph3Sn units joined by 1,3-azide bridges. In one unit, the geometry around tin is similar to that found for the monomeric HMPA adduct (2), which has trans-axial HMPA and azide ligands. The other unit in (1) has nonplanar -SnC3- groups connected by less symmetric 1,3-azide bridges and thus resembles the structure of isoelectronic triphenyltin isocyanate.Key words: triphenyltin azide, O- and N-donor adducts, far-IR/Raman, crystal structures.

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