Silaheterocycles 36 (1). Trichlorovinylsilane, lithium-tert-butyl, and 1,3-enynes: A versatile combination for the competitive formation of silacyclobutanes and silacyclobutenes

2000 ◽  
Vol 78 (11) ◽  
pp. 1445-1458 ◽  
Author(s):  
N Auner ◽  
M Grasmann ◽  
B Herrschaft ◽  
M Hummer
Keyword(s):  
Solid State ◽  
Triple Bond ◽  
Reaction Pathway ◽  
Membered Ring ◽  
State Structure ◽  
Orthorhombic Space Group ◽  
Multiple Bonds ◽  
X Ray ◽  
Tert Butyl ◽  
One Step

Equimolar amounts of trichlorovinylsilane (9), lithium-tert-butyl, and 1,3-enynes were reacted to yield the corresponding isomeric silacyclobutanes and silacyclobutenes competitively. As reaction pathway the mixture 9/tBuLi is discussed to give a silene equivalent, Cl2Si=CHCH2tBu (10), yielding the four-membered ring silacycles by formal [2 + 2] cycloaddition reactions of 10 with the C=C double or the C=C triple bond of the 1,3-enyne. The relative ratio of the products formed depends on the polarity of the multiple bonds in the enyne, which is mainly determined by the substituent pattern. Thus, from the organosubstituted 1,3-enynes R1 C=C-C(R2)=CR3R4 (R1 = Me, Et, SiMe3, Ph; R2 = H, Me, Ph; R3=Me, OMe, Ph; R4=H; and R1C=C-R' (R' = 1-cyclohexenyl, cyclohexanevinylidyne)) and 9/tBuLi the silacyclobutanes 12, 13, and 15 and the silacyclobutenes 14,16-24, and 27 (from 10 and 3-hexyne) are prepared in a one-step synthesis and isolated from the reaction mixtures. The silacyclobutanes and -butenes are thermally stable and can be distilled under vacuo up to temperatures of about 150°C without decomposition. The experimental results are confirmed qualitatively by semiempiric calculations at the AM-1 level and their analysis using FMO theory. The solid state structure of the silacyclobutene 19 (C17H30Cl2Si2) has been determined by single crystal X-ray diffractometry. 19 is orthorhombic, space group P212121, a = 1030.94(2) pm, b = 1244.6(2) pm, c = 1605.5(3) pm, Z = 4.Key words: neopentylsilene, dichloroneopentylsilene, silacyclobutenes, silacyclobutanes, 1,3-enynes.

Cyclic Alkyl(aryl)boranes for 1,1-Carboboration of Monoalkynyltin Compounds

2013 ◽  
Vol 68 (5-6) ◽  
pp. 493-502 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Peter Thoma ◽  
Wolfgang Milius
Keyword(s):  
Solid State ◽  
High Selectivity ◽  
Ring Expansion ◽  
Membered Ring ◽  
Reaction Products ◽  
State Structure ◽  
Alkyl Aryl ◽  
X Ray ◽  
X Ray Crystallography ◽  
Nmr Techniques

Two cyclic alkyl(aryl)boranes, a 1-bora-indane derivative 1, and a tricyclic derivative 4, containing the boron atom in a six-membered ring, were structurally characterized by NMR techniques in solution. The solid-state structure of the 1-bora-indane 1 was determined by X-ray crystallography. The reactivity of these cyclic alkyl(aryl)boranes towards monoalkynyltin compounds, Me3Sn-C≡C-Me and Me3Sn-C C-Fc (Fc=ferrocenyl), was studied using multinuclear magnetic resonance methods (1H, 11B, 13C, 119Sn NMR). Novel alkenylboranes were formed by 1,1-carboboration reactions. This process involves an expansion of both five- and six-membered rings. Insertion into the respective B-C(aryl) bond was preferred with high selectivity. In the case of the six-membered ring in 4, the ring expansion to seven-membered rings proved to be readily reversible, and the thermodynamically stable reaction products were formed by ring contraction and concomitant transfer of the exocyclic B-nPr group

Preparation and structure of 2-chloro-1,3-dimethyldiaza-2-arsenane, 1,3-dimethyldiaza-2-arsenanium tetrachlorogallate, and butadiene cycloadducts of diazarsenium cations

1996 ◽  
Vol 74 (11) ◽  
pp. 2209-2216 ◽  
Author(s):  
Neil Burford ◽  
Charles L.B. Macdonald ◽  
Trenton M. Parks ◽  
Gang Wu ◽  
Borzena Borecka ◽  
...  
Keyword(s):  
Solid State ◽  
Chloride Ion ◽  
2D Nmr ◽  
Diels Alder ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
State Structure ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

1,3-Dimethyldiaza-2-arsenanium tetrachlorogallate (crystal data: C5H12AsCl4GaN2, M = 386.61, orthorhombic, space group Pca21, a = 14.432(3) Å, b = 6.7580(14) Å, c = 13.905(3) Å, V = 1356.2(5) Å3) is synthesized by the routine chloride ion abstraction procedure from 2-chloro-1,3-dimethyldiaza-2-arsenane (crystal data: C5H12AsClN2, M = 210.54, monoclinic, space group P21/n, a = 7.206(1) Å, b = 9.650(1) Å, c = 13.021(2) Å, β = 99.61(2)°, V = 892.8(2) Å3). X-ray crystallographic studies of both compounds are described together with that for 2-chloro-1,3-dimethyldiaza-2-arsolidine (crystal data: C4H10AsClN2, M = 196.51, monoclinic, space group P21/n, a = 6.959(7) Å, b = 9.23(2) Å, c = 12.14(2) Å, β = 95.4(1)°, V = 777(4) Å3) providing useful structural comparisons. In contrast to the closely related arsolidinium salts, the diazarsenanium gallate exhibits a monomeric solid state structure. Rapid and quantitative cycloaddition reactions of the diazarsolidinium and diazarsenanium cations with 2,4-dimethylbutadiene give similar cycloadducts. The Diels–Alder type arsolidinium adduct is structurally characterized (crystal data: C10H20AsCl4GaN2, M = 454.73, orthorhombic, space group Pca21, a = 18.471(2) Å, b = 7.000(2) Å, c = 13.738(1) Å, V = 1776.2(8) Å3), and the related structure of the arsenanium cycloadduct is confirmed by 2D NMR. Key words: arsenium, cycloadditions, arsenanium, Diels–Alder, cyclochloroarsines.

scholarly journals Synthesis and structure of the donor-free potassium silanide K[SiPh3]

2019 ◽  
Vol 74 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Edith Alig ◽  
Isabelle Georg ◽  
Inge Sänger ◽  
Lothar Fink ◽  
Matthias Wagner ◽  
...  
Keyword(s):  
Solid State ◽  
Room Temperature ◽  
State Structure ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Solid State Structure ◽  
X Ray ◽  
Phenyl Rings ◽  
Short Contacts

AbstractThe donor-free potassium silanide K[SiPh3] was prepared by the reaction of hexaphenyldisilane, Ph3Si–SiPh3, with potassium metal in benzene at room temperature. The solid-state structure, determined by powder X-ray diffraction consists of {K[SiPh3]}2 units, which interact with adjacent dimers to form an infinite chain along the crystallographic c axis (orthorhombic, space group Cmc21, Z=4). The structure features short contacts between the π system of the phenyl rings and the potassium atoms of neighbouring K[SiPh3] units.

scholarly journals Hydrothermal Synthesis of Iridium-Substituted NaTaO3 Perovskites

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1537
Author(s):  
David L. Burnett ◽  
Christopher D. Vincent ◽  
Jasmine A. Clayton ◽  
Reza J. Kashtiban ◽  
Richard I. Walton
Keyword(s):  
Significant Proportion ◽  
Edge Length ◽  
Perovskite Oxide ◽  
Hydrogen Yield ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Profile Fitting ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
One Step

Iridium-containing NaTaO3 is produced using a one-step hydrothermal crystallisation from Ta2O5 and IrCl3 in an aqueous solution of 10 M NaOH in 40 vol% H2O2 heated at 240 °C. Although a nominal replacement of 50% of Ta by Ir was attempted, the amount of Ir included in the perovskite oxide was only up to 15 mol%. The materials are formed as crystalline powders comprising cube-shaped crystallites around 100 nm in edge length, as seen by scanning transmission electron microscopy. Energy dispersive X-ray mapping shows an even dispersion of Ir through the crystallites. Profile fitting of powder X-ray diffraction (XRD) shows expanded unit cell volumes (orthorhombic space group Pbnm) compared to the parent NaTaO3, while XANES spectroscopy at the Ir LIII-edge reveals that the highest Ir-content materials contain Ir4+. The inclusion of Ir4+ into the perovskite by replacement of Ta5+ implies the presence of charge-balancing defects and upon heat treatment the iridium is extruded from the perovskite at around 600 C in air, with the presence of metallic iridium seen by in situ powder XRD. The highest Ir-content material was loaded with Pt and examined for photocatalytic evolution of H2 from aqueous methanol. Compared to the parent NaTaO3, the Ir-substituted material shows a more than ten-fold enhancement of hydrogen yield with a significant proportion ascribed to visible light absorption.

Synthesis and structural characterization of a magnesium phthalocyanine(3–) anion

2012 ◽  
Vol 16 (01) ◽  
pp. 154-162 ◽  
Author(s):  
Edwin W.Y. Wong ◽  
Daniel B. Leznoff
Keyword(s):  
Absorption Spectrum ◽  
Solid State ◽  
Single Crystal ◽  
Structural Characterization ◽  
Heterometallic Complex ◽  
State Structure ◽  
Solid State Structure ◽  
X Ray ◽  
X Ray Crystallography

The reduction of magnesium phthalocyanine (MgPc) with 2.2 equivalents of potassium graphite in 1,2-dimethoxyethane (DME) gives [K2(DME)4]PcMg(OH)(1) in 67% yield. Compound 1 was structurally characterized using single crystal X-ray crystallography and was found to be a monomeric, heterometallic complex consisting of a μ3-OH ligand that bridges a [MgIIPc3-]- anion to two potassium cations solvated by four DME molecules. An absorption spectrum of 1 confirms the Pc ligand is singly reduced and has a 3–charge. The solid-state structure of 1 does not indicate breaking of the aromaticity of the Pc ligand. Compound 1 is only the second Pc3- complex and the first reduced MgPc to be isolated and structurally characterized.

Unprecedented Hexa- and Undecanuclear Frameworks of Two New Tin(IV) Oxo Clusters Resulting from Partial Debenzylation Reactions

2010 ◽  
Vol 65 (11) ◽  
pp. 1293-s1308 ◽  
Author(s):  
Laurent Plasseraud ◽  
Hélène Cattey ◽  
Philippe Richard
Keyword(s):  
Solid State ◽  
1H Nmr Spectroscopy ◽  
Trifluoromethanesulfonic Acid ◽  
Synthetic Route ◽  
State Structure ◽  
X Ray Diffraction ◽  
Neutral Cluster ◽  
Broad Resonance ◽  
X Ray ◽  
The Core

A new and facile synthetic route to the known neutral cluster ((PhCH2)2SnO)6[((PhCH2)2SnOH)2- (CO3)]2 (2) as well as its reactivity toward trifluoromethanesulfonic acid (HO3SCF3, TfOH) are reported. The solid-state structure of the new solvate 2·6C7H8 has been determined by single-crystal X-ray diffraction. The core of 2 can be described as a pair of coplanar pentanuclear [(PhCH2)2SnO]5 ladders bridged at their ends by two carbonate groups. Successive additions of TfOH to a suspension of 2 in CD3CN were monitored by 119Sn{1H} NMR spectroscopy showing the transformation of the fingerprint of 2 (δ = −244, −246, −306 ppm), via new upfield signals, to a final broad resonance located at δ = −474 ppm. Thereafter, two unprecedented ionic monobenzyltin(IV) oxo clusters, 3 and 4, resulting from a debenzylation reaction and exhibiting unusual hexa- and undecanuclear frameworks, respectively, have been isolated as single crystals.

Structural Study of an Acyclic Diterpene From Eremophila Species

1996 ◽  
Vol 49 (6) ◽  
pp. 701 ◽  
Author(s):  
YM Syah ◽  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Structural Study ◽  
Room Temperature ◽  
State Structure ◽  
Solid State Structure ◽  
X Ray

The solid-state structure of the semicarbazone derivative (3) of the aldehyde diacid (1), an acyclic diterpene isolated from Eremophila species, has been determined by a single-crystal room-temperature X-ray study. Crystals of (3) are triclinic, Pī , a 14.642(7), b 14.371(6), c 12.823(6) Ǻ, α 76.59(4), β 66.09(4), γ 72.97(4)°, Z = 4; R was 0.052 for 2265 independent 'observed' (I > 3σ(I)) diffractometer reflections.

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)°].

Synthese von vier- und achtgliedrigen Heterocyclen, die Schwefel, Stickstoff und Phosphor enthalten, und die Röntgenstrukturanalyse eines phosphorhaltigen achtgliedrigen SN-Ringes / Synthesis of Four- and Eight-Membered Heterocycles Containing Sulfur, Nitrogen and Phosphorus and the X-ray Structure of a Phosphorus-Containing Eight-Membered SN-Ring

1980 ◽  
Vol 35 (9) ◽  
pp. 1130-1136 ◽  
Author(s):  
Herbert W. Roesky ◽  
Sushil K. Mehrotra ◽  
Christoph Platte ◽  
Djamrnschid Amirzadeh-Asl ◽  
Bernhard Roth
Keyword(s):  
Tertiary Amine ◽  
Phosphorus Atom ◽  
Mass Spectra ◽  
Phosphorus Pentachloride ◽  
Membered Ring ◽  
Phosphonium Salts ◽  
Nitrogen And Phosphorus ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Phosphorus Containing

Eight-membered rings of the composition [SO2(NR)2PR′]2 3a-d with R = CH3, C2H5, and R′ = CH3, C6H5, were prepared from substituted sulfamides and dichlorophosphanes in the presence of a tertiary amine. These molecules were characterized on the basis of 1H and 31P NMR investigations and of mass spectra. 3 a reacts with phosphorus pentachloride to yield the spirocyclic derivative 4 with the phosphorus atom in the center of two four-membered rings. Methyliodide reacts with 3 a and 3 b under opening of the eight- membered ring and formation of phosphonium salts. The structure of 3 b is discussed in detail. 8b crystallizes in the orthorhombic space group Pna 21 with a = 12.60(0), b = 13.27(1), c = 12.62(4) Å.

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