Novel Intramolecular CAryl–S Bond Activation by an Electron Rich, Ring-Expanded-NHC-Rh centre: A Combined Experimental and DFT Study

The reaction of (o-MeSPh)-N-functionalized tetrahydropyrimidinium salts with KN(SiMe3)2 and [Rh(COD)Cl]2 in THF leads to the formation of a novel dimeric RhIII bis-carbene complex. The reaction involves the unexpected cleavage/oxidative addition of the aryl-sulfur bond to give dimeric metallated RhIII with bridging MeS< moieties. This unusual reaction is probably a consequence of the sterically imposing structure and strong donor capacity of ring-expanded N-heterocyclic carbenes (RE-NHCs). An X-ray structure of the [(Ph,DIPP-NHC)Rh(Cl)(SMe)2] product complex has been obtained, and DFT studies were undertaken to gain an insight into the reaction pathway.

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Reactions of Titanocene- and Zirconocene-Bis(trimethylsilyl)acetylene Complexes with Selected Heterocyclic and Aromatic NH and OH Acid Compounds

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20070475 ◽

2007 ◽

Vol 72 (4) ◽

pp. 475-491 ◽

Cited By ~ 6

Author(s):

Perdita Arndt ◽

Vladimir V. Burlakov ◽

Ulrike Jäger-Fiedler ◽

Marcus Klahn ◽

Anke Spannenberg ◽

...

Keyword(s):

Bond Activation ◽

Reaction Pathway ◽

Reaction Products ◽

X Ray ◽

X Ray Crystallography

The titanocene complexes Cp'2Ti(η2-Me3SiC2SiMe3) (Cp' = Cp (1), Cp* (2)) react with pyrrole under the formation of the titanium(III) mono-N-pyrrolides Cp'2Ti(NC4H4) (Cp' = Cp (6), Cp* (7)); whereas the corresponding zirconocene system Cp2Zr(η2-Me3SiC2SiMe3)(thf) (3) forms in a different reaction pathway first the Cp2Zr(NC4H4)[C(SiMe3)=CH(SiMe3)] (8) and then the zirconium(IV) bis-N-pyrrolide Cp2Zr(NC4H4)2 (11). With Cp*2Zr(η2-Me3SiC2SiMe3) (4) and pyrrole, the zirconium(IV) mono-N-pyrrolide with an agostic alkenyl group Cp*2Zr(NC4H4)[C(SiMe3)=CH(SiMe3)] (9) was obtained. In the reaction of the ethylenebistetrahydroindenyl (ebthi) complex rac-(ebthi)Zr(η2-Me3SiC2SiMe3) (5) with 2,3,5,6-tetrafluoroaniline under N-H bond activation, a complex with an agostic alkenyl group rac-(ebthi)Zr(NH-C6HF4)[C(SiMe3)=CH(SiMe3)] (10) was formed. Compound 10 reacts with additional 2,3,5,6-tetrafluoroaniline to give the bisanilide rac-(ebthi)Zr(NH-C6HF4)2 (12) which was obtained directly from 5 with two equivalents of 2,3,5,6-tetrafluoroaniline. In reactions of complex 5 with unsubstituted aniline to rac-(ebthi)Zr(NH-C6H5)2 (13) and with pentafluorophenol to bisphenolate rac-(ebthi)Zr(O-C6F5)2 (14), no intermediates could be isolated. The new reaction products 6, 9, 10, 12, 13 and 14 were investigated by X-ray crystallography.

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Synthesis, catalysis, and DFT study of a ruthenium carbene complex bearing a 1,2-dicarbadodecaborane (12)-1,2-dithiolate ligand

Dalton Transactions ◽

10.1039/c8dt04290j ◽

2019 ◽

Vol 48 (8) ◽

pp. 2646-2656

Author(s):

Tao Wang ◽

Botao Wu ◽

Weijie Guo ◽

Shutao Wu ◽

Huiqing Zhang ◽

...

Keyword(s):

Single Crystal ◽

Dft Study ◽

X Ray Diffraction ◽

X Ray ◽

Carbene Complex

A ruthenium carbene catalyst containing a 1,2-dicarbadodecaborane(12)-1,2-dithiolate ligand was synthesized, and the structure was determined by single crystal X-ray diffraction.

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Hydrogénation of phosphido bridged ruthenium clusters. A view of P—C bond activation and cleavage in the coordinatively unsaturated molecule Ru3(CO)9(μ2-PPh2)(μ2-H): conversion of μ2-PPh2 to μ3-PPh

Canadian Journal of Chemistry ◽

10.1139/v82-015 ◽

1982 ◽

Vol 60 (1) ◽

pp. 87-90 ◽

Cited By ~ 56

Author(s):

Shane A. Maclaughlin ◽

Arthur J. Carty ◽

Nicholas J. Taylor

Keyword(s):

Bond Activation ◽

Phenyl Group ◽

Synthetic Route ◽

X Ray Diffraction ◽

Ruthenium Clusters ◽

X Ray ◽

Ruthenium Atom ◽

Unsaturated Molecule ◽

Insight Into

Treatment of Ru3(CO)8(μ3-η2-C≡CR)(μ2-PPh2)(R = But, Pri) with dihydrogen liberates olefin (CH2=CHR) and generates the coordinatively unsaturated cluster Ru3(CO)9(μ2-PPh2)(μ2-H) which has been shown by X-ray diffraction to have an unprecedented μ2-phosphido bridge in which a P—phenyl group interacts with an electron deficient ruthenium atom. This molecule provides an insight into P—C bond activation leading to cleavage. Further reaction of Ru3(CO)9(μ2-PPh2)(μ2-H) with H2 leads to the phosphinidene cluster Ru3(CO)9(μ3-PPh)(μ2-H)2 via elimination of benzene. Conversion of Ru3(CO)9(μ2-PPh2)(μ2-H) to another phosphinidene cluster Ru4(CO)13(μ3-PPh) occurs on pyrolysis. Hydrogénation of multi-site bound acetylides with H2 is a potentially useful synthetic route to unsaturated clusters. Hydrogenative conversion of μ2-PPh2 to μ3-PPh groups has significance for the synthesis of phosphinidene capped molecules as well as the chemistry of phosphido bridged clusters.

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Quantitative Analysis Of X-Ray Images From Geological Materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010013482x ◽

1990 ◽

Vol 48 (2) ◽

pp. 244-245

Author(s):

J. M. Paque ◽

R. Browning ◽

P. L. King ◽

P. Pianetta

Keyword(s):

Quantitative Analysis ◽

Bulk Composition ◽

Principal Component ◽

Analytical Description ◽

Bulk Sample ◽

Geological Samples ◽

X Ray ◽

Software And Hardware ◽

And Storage ◽

Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

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Copper–oxygen Dynamics in Tyrosinase

10.26434/chemrxiv.9255251 ◽

2019 ◽

Author(s):

Nobutaka Fujieda ◽

Sachiko Yanagisawa ◽

Minoru Kubo ◽

Genji Kurisu ◽

Shinobu Itoh

Keyword(s):

Catalytic Mechanism ◽

Substrate Binding ◽

Active Form ◽

Copper Ion ◽

Atomic Resolution ◽

Oxygen Species ◽

X Ray ◽

Oxygen Dynamics ◽

Insight Into ◽

Copper Centre

To unveil the activation of dioxygen on the copper centre (Cu2O2core) of tyrosinase, we performed X-ray crystallograpy with active-form tyrosinase at near atomic resolution. This study provided a novel insight into the catalytic mechanism of the tyrosinase, including the rearrangement of copper-oxygen species as well as the intramolecular migration of copper ion induced by substrate-binding.

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Mechanistic insights into the C–H activation of methane mediated by the unsupported and silica-supported VO2OH and CrOOH: a DFT study

RSC Advances ◽

10.1039/d0ra10785a ◽

2021 ◽

Vol 11 (19) ◽

pp. 11295-11303

Author(s):

Shidong Zhao ◽

Lishuang Ma ◽

Yanyan Xi ◽

Hongyan Shang ◽

Xufeng Lin

Keyword(s):

Bond Activation ◽

Support Effect ◽

Dft Study

The support effect of silica was studied with DFT for the C–H bond activation of methane on a V(v) or a Cr(iii) site. Both of the PCET and HAT mechanisms were computationally characterized.

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Mechanistic insight into the reaction pathway of peroxomonosulfate-initiated decomplexation of EDTA-NiII under alkaline conditions: Formation of high-valent Ni intermediate

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2021.120375 ◽

2021 ◽

pp. 120375

Author(s):

Sheng Liang ◽

Xiaoting Hu ◽

Haolin Xu ◽

Zhenchao Lei ◽

Chaohai Wei ◽

...

Keyword(s):

Reaction Pathway ◽

Mechanistic Insight ◽

Alkaline Conditions ◽

High Valent ◽

Insight Into

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Intercluster exchanges leading to hydride-centered bimetallic clusters: a multi-NMR, X-ray crystallographic, and DFT Study

Dalton Transactions ◽

10.1039/d1dt00072a ◽

2021 ◽

Author(s):

Yu-Jie Zhong ◽

Jian-Hong Liao ◽

Tzu-Hao Chiu ◽

Ying-Yann Wu ◽

Samia Kahlal ◽

...

Keyword(s):

Dft Study ◽

Bimetallic Clusters ◽

X Ray

Encouraged by the successful syntheses of alloy nanoclusters (or nanoparticles) via intercluster (or interparticle) reactions, herein we apply this methodology to prepare a series of bimetallic hydride clusters. Mixing of...

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Self-Assembled Bimetallic Aluminum-Salen Catalyst for the Cyclic Carbonates Synthesis

Molecules ◽

10.3390/molecules26134097 ◽

2021 ◽

Vol 26 (13) ◽

pp. 4097

Author(s):

Wooyong Seong ◽

Hyungwoo Hahm ◽

Seyong Kim ◽

Jongwoo Park ◽

Khalil A. Abboud ◽

...

Keyword(s):

Hydrogen Bonding ◽

Self Assembly ◽

Reaction Pathway ◽

Kinetic Studies ◽

Cyclic Carbonate ◽

Reaction Conditions ◽

Formation Reaction ◽

X Ray ◽

Carbonate Formation ◽

Salen Aluminum

Bimetallic bis-urea functionalized salen-aluminum catalysts have been developed for cyclic carbonate synthesis from epoxides and CO2. The urea moiety provides a bimetallic scaffold through hydrogen bonding, which expedites the cyclic carbonate formation reaction under mild reaction conditions. The turnover frequency (TOF) of the bis-urea salen Al catalyst is three times higher than that of a μ-oxo-bridged catalyst, and 13 times higher than that of a monomeric salen aluminum catalyst. The bimetallic reaction pathway is suggested based on urea additive studies and kinetic studies. Additionally, the X-ray crystal structure of a bis-urea salen Ni complex supports the self-assembly of the bis-urea salen metal complex through hydrogen bonding.

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