Phosphine interactions with high oxidation state metals
作者:Kelly E. Aldrich、Brennan S. Billow、Richard J. Staples、Aaron L. Odom
DOI:10.1016/j.poly.2018.11.027
日期:2019.2
have focused on their interactions with low valent transition metals. From these investigations, it is now widely accepted that there are two major electronic interactions between the PE3 ligand and a low valent metal: a σ-donor bond between the metal and phosphorus and a π-acceptor interaction, where the phosphorus accepts electron density from the metal. The π-acceptor interaction is a form of negative
Structural and functional synthetic model of mono-iron hydrogenase featuring an anthracene scaffold
作者:Junhyeok Seo、Taylor A. Manes、Michael J. Rose
DOI:10.1038/nchem.2707
日期:2017.6
a scaffold-based synthetic approach by which to model mono-iron hydrogenase using an anthracene framework, which supports a biomimetic fac-C,N,S coordination motif to an iron(II) centre. This arrangement includes the biomimetic and organometallic Fe–C σ bond, which enables bidirectional activity reminiscent of the native enzyme: the complex activates H2 under mild conditions, and catalyses C–H hydride
Solution Chemistry of a Water-Soluble η<sup>2</sup>-H<sub>2</sub> Ruthenium Complex: Evidence for Coordinated H<sub>2</sub> Acting as a Hydrogen Bond Donor
作者:Nathaniel K. Szymczak、Lev N. Zakharov、David R. Tyler
DOI:10.1021/ja065532f
日期:2006.12.1
to participate in intermolecular hydrogenbonding in solution has long been an unresolved issue. Such species are proposed to be key intermediates in numerous important reactions such as the proton-transfer pathway of H2 production by hydrogenase enzymes. We present the synthesis of several new water-soluble ruthenium coordination complexes including an eta2-H2 complex that is surprisingly inert to substitution
Precursors to dinitrogen reduction: structures and reactivity of trans-[Fe(DMeOPrPE)2(η2-H2)H]+ and trans-[Fe(DMeOPrPE)2(N2)H]+
作者:Justin L. Crossland、Douglas M. Young、Lev N. Zakharov、David R. Tyler
DOI:10.1039/b911066f
日期:——
trans-[Fe(DMeOPrPE)2(H2)H]+ and trans-[Fe(DMeOPrPE)2(N2)H]+ (DMeOPrPE = 1,2-bis(dimethoxypropylphosphino)ethane) were synthesized and their structures determined by X-ray crystallography. These complexes are important species in a dinitrogen reduction scheme involving protonation of an iron(0) dinitrogen complex to produce ammonia. The rates of substitution of the coordinated H2 and N2 molecules with acetonitrile were monitored in a variety of organic solvents. The coordinated N2 substituted â¼6 times faster than H2, but surprisingly the solvent had little effect on the observed rates. The results suggest that the H2 molecule in trans-[Fe(DMeOPrPE)2(H2)H]+ does not participate in hydrogen bonding to the bulk solvent, as was previously observed in the analogous Ru complex. The deprotonation of trans-[Fe(DMeOPrPE)2(N2)H]+ to yield Fe(DMeOPrPE)2N2 was investigated in the presence of a variety of anions, and it was found that the anion facilitates the reaction through an ion-pairing interaction in which the anion removes electron density from the hydride ligand.
Accessing Low-Valent Inorganic Cations by Using an Extremely Bulky N-Heterocyclic Carbene
作者:Matthew M. D. Roy、Paul A. Lummis、Michael J. Ferguson、Robert McDonald、Eric Rivard
DOI:10.1002/chem.201703215
日期:2017.8.22
The extremely bulkyN‐heterocycliccarbene (NHC), ITr (ITr=[(HCNCPh3)2C:]) featuring sterically shielding umbrella‐shaped trityl (CPh3) substituents was prepared. This NHC features the highest percent buried volume (%Vbur) to date, and was used to form a thermally stable quasi one‐coordinate thallium(I) cation [ITr‐Tl]+. This TlI adduct and the corresponding lithium complex [ITr⋅Li(OEt2)]+ are versatile