645-49-8Relevant academic research and scientific papers
Redox behaviour of ([fc(NPiPr2)2]Fe)2, formation of an iron-iron bond and cleavage of azobenzene
Pick, Fraser S.,Leznoff, Daniel B.,Fryzuk, Michael D.
, p. 10925 - 10931 (2018)
The redox behaviour of the dimeric tetrairon complex, ([fc(NPiPr2)2]Fe)2 (where fc(NPiPr2)2 = 1,1′-(C5H4NPiPr2)2Fe) has been investigated. Upon reduction with KC8 an Fe-Fe bond is formed with the complex maintaining a high spin configuration and having the formula [K(THF)6]([fc(NPiPr2)2]Fe)2. In contrast, oxidation of the complex is ligand based; for example, addition of the 1,2-diiodoethane (I2 equivalent) results in the formation of the monomeric iron(ii) diiodide [fc(NiPr2I)2]FeI2 wherein the phosphine is oxidized. The dimeric tetrairon complex reacts photolytically with azobenzene, cleaving the NN double bond and forming the new monomeric bis(phosphoramidate) iron complex. [fc(NP(NPh)iPr2)2]Fe. Characterization of these paramagnetic complexes was accomplished by magnetic susceptibility studies and X-ray analyses.
Ring carbon functionalization of N-heterocyclic carbene ligand with ester groups. Electronic effect of ester groups on coordination properties
Hara, Kenji,Kanamori, Yoshikazu,Sawamura, Masaya
, p. 1781 - 1786 (2006)
Palladium complexes with an imidazol-2-ylidene ligand functionalized with ester groups at its 4,5-positions were synthesized from a readily available imidazole derivative. σ-Donation from the carbene ligand to the palladium atom is considerably weakened by functionalization with the two ester moieties.
Picosecond kinetics of trans-cis-photoisomerisations: from jet-cooled molecules to compressed solutions
Schroeder, J?rg
, p. 643 - 650 (1997)
The understanding of photoisomerisation reactions involving large amplitude motion is discussed with special emphasis on the merits of systematic studies over wide ranges of physical conditions. It appears that the friction in such cases is proportional to macroscopic solvent viscosity η, and the original Kramers theory is sufficient to describe the effect of friction in the range from intermediate to strong damping, i.e. from low viscosity fluid to compressed high viscosity liquid solution. This one-dimensional model may be connected to multidimensional unimolecular rate theory to obtain a representation of the density dependence of the rate coefficient down to the thermal collisionless regime. The apparent failure of this approach in the case of /rans-stilbene can be traced to modifications of the excited state PES by the solvent. This interpretation is consistent over the entire range of physical conditions studied, starting at the jet-cooled isolated molecule and solvent cluster and ending in compressed liquid solution at very high viscosities. It is shown that detailed information about the PES is urgently needed to provide safer ground for a profound understanding of the photoisomerisation dynamics. VCH Verlagsgesellschafl mbH, 1997.
Cluster and barrier effects in the temperature and pressure dependence of the photoisomerization of trans-stilbene
Schroeder, J.,Schwarzer, D.,Troe, J.,Voss, F.
, p. 2393 - 2404 (1990)
The pressure and temperature dependence of the photoisomerization rate coeficient of trans-stilbene in the S1 state have been measured in the solvents C2H6, C3H8, C4H10, Xe, Co2, SF6, and CHF3.At constant temperature, the pressure dependences up to 6 kbar can be well represented by the Kramers-Smoluchowski model.The comparison of results in different solvents cleary indicates the importance of reactant-solvent cluster formation modifying the height and imaginary frequency of the barrier.The change of the temperature dependence with pressure points towards a multidimensional barrier of nonseparable character.Multidimensional barrier effects manifest themselves most clearly via the temperature dependence of the rate coefficient in the Kramers-Smoluchowski limit.
A parahydrogen study of catalytic hydrogenation by diphosphane-substituted triruthenium clusters
Prestwich, Tom G.,Blazina, Damir,Duckett, Simon B.,Dyson, Paul J.
, p. 4381 - 4387 (2004)
The diphosphane-substituted clusters [Ru3(CO) 10(dppe)] and [Ru3(CO)8(dppe)2] [dppe = 1,2-bis(diphenylphosphanyl)e-thane] are shown to catalytically hydrogenate diphenylacetylene. This process is high
Visible-Light-Induced, Metal-Free Carbene Insertion into B-H Bonds between Acylsilanes and Pinacolborane
Ye, Jian-Heng,Quach, Linda,Paulisch, Tiffany,Glorius, Frank
, p. 16227 - 16231 (2019)
Carbene insertion reactions with B-H bonds are a challenging but promising method for the synthesis of organoboranes. Herein, we report visible-light-induced B-H insertions of HBpin with acylsilane. This metal-free and operationally simple reaction proceeds in an atom-economical way with broad substrate scope under mild reaction conditions, affording a variety of important α-alkoxyorganoboronate esters in quantitative yields. Control experiments and density functional theory calculations suggest that the siloxycarbene generation from the T1 state of acylsilane and the carbene insertion into the B-H bond occurred in a concerted manner.
Cycloaddition of Dialkylalumanyl Anion toward Unsaturated Hydrocarbons in (1+2) and (1+4) Modes
Nakano, Ryo,Sugita, Kengo,Yamashita, Makoto
, (2019)
The reactivity of dialkylalumanyl anion (1) towards naphthalene, anthracene, diphenylacetylene, and (E)/(Z)-stilbenes was investigated. The compound 1 reacts with naphthalene and anthracene through (1+4) cyclization, giving Al-containing norbornadiene derivatives. In the reaction of 1 with diphenylacetylene and (E)/(Z)-stilbenes, (1+2) cyclization proceeded to form Al-C-C three-membered rings. Cyclization toward (E)- or (Z)-stilbenes solely gave a trans-cycloadduct. DFT calculations revealed that the cycloaddition of 1 with (Z)-stilbene proceeds via a single transition state with a carbanion character, which results in the selectivity towards the trans-cycloadduct.
Pyrene-benzoylthiophene bichromophores as selective triplet photosensitizers
Perez-Prieto, Julia,Perez, Lourdes Pastor,Gonzalez-Bejar, Maria,Miranda, Miguel A.,Stiriba, Salah-Eddine
, p. 5569 - 5571 (2005)
Combination of the pyrene and benzoylthiophene units constitutes an interesting approach to design bichromophoric photosensitizers with increased intersystem crossing quantum yield and enhanced selectivity. The potential of this strategy has been illustrated in the present work by using a model photoisomerization reaction. The Royal Society of Chemistry 2005.
Donor-Stabilized Silacyclobutanone: A Precursor of 1-Silaketene via Retro-[2 + 2]-Cycloaddition Reaction at Room Temperature
Troadec, Thibault,Lopez Reyes, Morelia,Rodriguez, Ricardo,Baceiredo, Antoine,Saffon-Merceron, Nathalie,Branchadell, Vicen?,Kato, Tsuyoshi
, p. 2965 - 2968 (2016)
The synthesis of donor-stabilized silacyclobutanone 2 was successfully realized by the reaction of silacyclopropylidene 1 with benzaldehyde in the presence of a Lewis acid catalyst. Of particular interest, silacyclobutanone 2 evolves at room temperature via a retro-[2 + 2]-cycloaddition reaction, leading to an original NHC-stabilized 1-silaketene 4 and cis-stilbene.
Insights into the heck reaction with PCP pincer palladium(II) complexes
Eberhard, Michael R.
, p. 2125 - 2128 (2004)
The Heck reaction of phenyl halides with styrene using a series of related PCP pincer palladium(II) complexes was studied in order to evaluate the effect of ligand structure and electronics on the catalytic activity and to investigate the nature of the catalyst species. We suggest these pincer complexes are precatalysts for highly active forms of metallic palladium. This conclusion is based on kinetic studies (induction periods, sigmoidal kinetics), Hg drop tests, quantitative poisoning experiments, and NMR studies.
