108150-67-0Relevant academic research and scientific papers
Bisdihydrogenhydridoiron(II) Tetraphenylborate as a Model for the Function of Nitrogenases
Hills, Adrian,Hughes, David L.,Jimenez-Tenorio, Manuel,Leigh, G. Jeffery,Rowley, Adrian T.
, p. 3041 - 3050 (2007/10/02)
The trihydride complex (+) (dmpe = Me2PCH2CH2PMe2) is best represented as (+), with the H-H separation in the H2 being ca. 0.81 Angstroem.The H2 can be replaced by N2, CO, MeCN, MeNC and C2H4.The dinitrogen complex (+) may be deprotonated to yield the solution-stable, trigonal-bipyramidal species , which can be reprotonated by HCl to yield , N2, H2 and NH3.The crystal structures of BPh4 and BPh4 have been determined.
Reactions of Bis(dihydrogen)hydridoiron(1+) with Alkynes
Hughes, David L.,Jimenez-Tenorio, Manuel,Leigh, G. Jeffery,Rowley, Adrian T.
, p. 3151 - 3162 (2007/10/02)
The compounds BPh4 and BPh4 (dmpe = Me2PCH2CH2PMe2 and depe = Et2PCH2CH2PEt2) reacted with terminal alkynes R'CCH (R = Me, i-Pr or Ph) to yield a variety of structures, apparently formed in sequence, bis(alkynyl), alkynyl(vinylidene) and substituted butenynyl complexes of iron(II), which also contain bis(diphosphines).The structures of trans-BF4, trans-BF4, and have been determined and the interconversions of the complexes are discussed.
Preparation and spectroscopic properties of the η2-dihydrogen complexes [MH(η2-H2)(PR2CH2CH 2PR2)2]+ (M = Fe, Ru; Ru; R = Ph, Et) and trends in properties down the iron group triad
Bautista, Maria T.,Cappellani, E. Paul,Drouin, Samantha D.,Morris, Robert H.,Schweitzer, Caroline T.,Sella, Andrea,Zubkowski, Jeffery
, p. 4876 - 4887 (2007/10/02)
Complexes trans-[M(H)(η22)L2]BF4 (L = PPh2CH2CH2PPh2 = dppe (1Fe, 1Ru), PEt2CH2CH2PEt2 = depe (2Ru)) are prepared by reaction of cis-M(H)2L2 with 1 equiv of HBF4·Et2O. Deprotonation of 1Ru by BuLi at 200 K, gives thermally unstable trans-Ru(H)2(dppe)2, which isomerizes to cis-Ru(H)2(dppe)2. Tetraphenylborate salts of the complexes 1Fe, 2Fc, and 2Ru are prepared by reaction of trans-M(Cl)(H)L2 with NaBPh4 under 1 atm of H2. 2Fe, 1Ru, and 2Ru can also be made directly from the complexes cis-MC2L2 by reaction with 1 atm of H2, excess NaBPh4, and 1 equiv of NaOEt (or NaOtBu) in THF. Some properties of the complexes [Os(H)(H2)(L)2]+ (L = dppe (1Os), depe (2Os)) are included to reveal trends down the triad of metals; ReH3(dppe)2 also provides useful comparisons. The terminal hydride stretching mode, ν(M-H), increases in frequency as Fe 31P chemical shifts increase in the order Fe 1H NMR spectra of isotopomers trans-[M(H)(η2-HD)L2]+ and trans-[M(D)(η2-HD)L2]+ give couplings 1J(H,D) that decrease as Ru > Fe > Os. The chemical shifts of the HD for these two isotopomers are quite different because of the higher trans influence of D than H. The chemical shift difference, δ(dihydrogen) - δ(terminal hydride), for complexes 1 and 2 also decreases as Ru > Fe > Os. The T1 values of the dihydrogen nuclei, T1(H2), and the hydride ligand, T1(H), were determined over the temperature range of 190-300 K for the complexes 2Fe and 2Ru in acetone-d6. Analysis of these and other data suggests H-H distances for the rapidly spinning H2 ligand of the Fe and Ru complexes are comparable at 0.87 ± 0.02 A?. An overall ordering of increasing distances is Ru ≈ Fe 2/D2 rates of exchange increases as Os 2 binding and hence the strength of the H2-metal bond likely increases as Ru 2]+ unit is a poorer π-back-bonder than the corresponding complexes of either Fe or Os and forms weaker σ-bonds than Os. Electrochemical and infrared data both indicate that the ease of oxidation of the binding sites for N2 and Cl- decreases as ReH(dppe)2 Gt; [FeH(depe)2]+ > [FeH(dppe)2]+ > [MH(depe)2]+ > [MH(dppe)2]+ (M = Ru, Os). H atom exchange between H2 and hydride ligands is monitored by variable-temperature 1H NMR, and spectra are simulated to give ΔG? values that decrease as Ru > Fe > Os and dppe > depe. This exchange likely proceeds via the homolytic cleavage of the H-H bond.
