Carbonylniobium chemistry

Syntheses and Properties of Homoleptic Carbonyl and Trifluorophosphane Niobates: [Nb(CO)6]-, [Nb(PF3)6]-and [Nb(CO)5]3- ,1

“…It is the sole example of a hydride containing niobium in a formally negative oxidation state, i.e., Nb(I−), and the only known simple unsubstituted carbonyl hydride of niobium. In this sense, [Nb(CO) 5 H] 2- may be thought of as a formal reduction product of the unknown Nb(CO) 6 H, for which only substituted derivatives have been reported; e.g., Nb(CO) 2 (dmpe) 2 H, dmpe = 1,2-bis(dimethylphosphino)ethane, [C 5 H 5 Nb(CO) 3 H] - , , Nb(CO) 4 (dppe)H, dppe = 1,2-bis(diphenylphosphino)ethane, and Nb(PF 3 ) 6 H (this work).…”

Probing Isotope Shifts in 103Rh and 195Pt NMR Spectra with Density Functional Theory

“…Cl Isotope Effects in [PtCl n (OH) 6-n ] 2-(n=1-5) complexes DFT geometry optimizations were performed to calculate the ground-state equilibrium and zero-point averaged structures in the gas-phase of all the relevant complexes. These structures were then used in the theoretical determination of the 195 Pt shielding tensors.…”

“…4,5,6,7 These effects are very large compared to those for other nuclei, when comparing the ranges of chemical shifts encountered. 8 McFarlane et al 4 2 ] complexes under carefully controlled spectroscopic conditions are resolved not only according to the statistically expected isotopologues, but also in some cases due to the isotopomers possible for these species, depending on whether a 35 Cl or 37 Cl ion is trans to the coordinated water molecule for each isotopologue in a given complex.…”

“…Thus, the protocol for the gas-phase calculations presented previously 24 , could still be a good approximation to the situation in solution, if effective error cancelation occurs, a possibility that will be explored in the present paper. 6−n ] 3−n (n = 3-6) complexes in equilibrated hydrochloric acid solutions, are also well-resolved into a distinctive fine-structure due to 35 Cl/ 37 Cl isotopologue and isotopomer effects, resulting in a unique NMR finger-print. 28 We now extend our computational protocol to [Rh 35 Cl isotopologues and isotopomers.…”

Niobium and Tantalum

“…576 Cyclic voltammetric measurements on these species revealed that both Nb m * ± Nb IV and Nb IV ^ Nb v couples are observed and are reversible. 576 Structurally, the d° complexes and Cp 2 Nb(SC 6 H 4 -4-Cl) 2 all have endo arrangements of their SR ligands (relative to the Cp rings) and large S-Nb-S angles (50). However, all other d l compounds are characterized by an exo configuration with phenyl rings bent back into the cleft formed by the Cp ligands (51).…”