The hydrogen-bridged disilyl cation 6 with an 1,8-naphthalenediyl backbone was synthesized and was characterized by NMR spectroscopy and X-ray crystallography, supported by quantum mechanical computations. The SiHSi linkage is symmetrical, corresponding to a single minimum potential, and the structural parameters are in agreement with the presence of a two electron-three center bond in 6. Treatment of disilyl cation 6 with alkyl fluorides yields the disilylfluoronium ion 10. The SiFSi group in the disilyl fluoronium ion 10 is symmetrical with an average SiF bond length of 175.9(8) and a bent angle beta = 130 degrees . Both cations catalyze the hydrodefluorination reaction of alkyl and benzyl fluorides to give alkanes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ja061800y | DOI Listing |
Inorg Chem
February 2023
Facultad de Química, Universidad del País Vasco (UPV/EHU), 20018 San Sebastián, Spain.
Siloxanes and silanols containing Si-H units are important building blocks for the synthesis of functionalized siloxane materials, and their synthesis is a current challenge. Herein, we report the selective synthesis of hydrosilanols, hydrosiloxanes, and silanodiols depending on the nature of the catalysts and the silane used. Two neutral ({MCl[SiMe(-CHPPh)]}; M = Rh, Ir) and two cationic ({M[SiMe(-CHPPh)](NCMe)}[BAr]; M = Rh, Ir) have been synthesized and their catalytic behavior toward hydrolysis of secondary silanes has been described.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2023
Research School of Chemistry, Australian National University, Acton, ACT 2601, Australia.
The synthesis, characterisation and reactivity of two isostructural anionic magnesium and calcium complexes is reported. By X-ray and neutron diffraction techniques, the anionic hydrides are shown to exist as dimers, held together by a range of interactions between the two anions and two bridging potassium cations. Unlike the vast proportion of previously reported dimeric group 2 hydrides, which have hydrides that bridge two group 2 centres, here the hydrides are shown to be "terminal", but stabilised by interactions with the potassium cations.
View Article and Find Full Text PDFJ Phys Chem A
December 2018
Department of Chemistry Iowa State University, Ames , Iowa 50014 , United States.
A comprehensive analysis of the bonding structure of the disilyl zirconocene amide cation {CpZr[N(SiHMe)]} is conducted by application of an intrinsic orbital localization method that yields quasi-atomic orbitals (QUAOs). An emphasis is placed on describing a previously characterized three-center two-electron interaction between zirconium, hydrogen, and silicon that presents structural and spectroscopic features similar to that of agostic bonds. Expressions of the first-order density matrix in terms of the QUAOs yields bond orders (BOs), kinetic bond orders (KBOs), and the extent of transfer of charge that are useful to determine the electronic nature of the Zr-H-Si bond.
View Article and Find Full Text PDFJ Am Chem Soc
March 2018
Institute of Inorganic Chemistry , RWTH Aachen University, Landoltweg 1 , Aachen 52056 , Germany.
The molecular strontium hydride [(MeTACD)Sr(μ-H)][SiPh] (2) was isolated as the dark red benzene solvate 2·CH in 69% yield from the reaction of [Sr(SiPh)(thf)] (1') with (MeTACD)H (1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane). This reaction can be considered as a redox process, with the Brønsted acidic amine proton in (MeTACD)H transformed into the hydride by the anion [SiPh]. Trace amounts of water resulted in the formation of [(MeTACD)Sr(μ-H)(μ-OH)][SiPh] (2*), which cocrystallized with 2.
View Article and Find Full Text PDFChemistry
December 2017
Department of Chemistry, Duke University, French Family Science Center, Durham, North Carolina, USA.
Si NMR spectroscopy was employed to evaluate the electron donor properties of the (L)Au fragments in the cationic gold (β,β-disilyl)vinylidene complexes [(L)Au=C=CSi(Me) CH CH Si(Me) ] B(C F ) [L=P(tBu) o-biphenyl or NHC] relative to the p-substituted aryl group in the α-aryl-(β,β-disilyl)vinyl cations [(p-C H X)-C= CSi(Me) CH CH Si(Me) ] B(C F ) . Similarly, F NMR was employed to evaluate the σ- and π-electron donor properties of the (L)Au fragments in the neutral gold fluorophenyl complexes (L)Au(C H F) and in the cationic (fluorophenyl)methoxycarbene complexes [(L)AuC(OMe)(C H F)] SbF [L=P(tBu) o-biphenyl or IPr] relative to the p-substituted aryl group of the protonated monofluorobenzophenones [(p-C H X)(C H F)COH] OTf . The results of these studies indicate that relative to p-substituted aryl groups, the gold (L)Au fragments [L=P(tBu) o-biphenyl or NHC] are significantly more inductively electron donating and are comparable π-donors and for this reason, the extent of (L)Au→C1 electron donation in gold carbene complexes appears to exceed that provided by a p-(dimethyamino)phenyl group.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!