108538-83-6Relevant articles and documents
Protonation Reactions of trans-M(H)(SPh)(dppe)2 (M = Ru, Os) to Give Thiol and Dihydrogen Complexes. X-ray Crystal Structure Determination of trans-Ru(H)(SPh)(dppe)2 and trans-[Os(H)(O2)(dppe)2](O3SCF3)
Bartucz, Tanya Y.,Golombek, Adina,Lough, Alan J.,Maltby, Patricia A.,Morris, Robert H.,Ramachandran, Ravindranath,Schlaf, Marcel
, p. 1555 - 1562 (2008/10/08)
The compounds trans-M(H)(SPh)(dppe)2 (M = Ru (1Ru), Os (1Os); dppe = 1,2-bis(diphenylphosphino)ethane) are synthesized by reaction of NaSPh with trans-[Ru(H2)(H)(dppe)2]BPh4 or with trans-Os(H)(Br)(dppe)2 in THF under Ar. They are characterized by 1H and 31P NMR, IR, FAB mass spectroscopy, elemental analyses, and cyclic voltammetry. The crystal structure determination of 1Ru verifies the trans, octahedral geometry, which is distorted by ring-ring interactions. The thiophenoxide ligand is coordinated to the metal in a bent configuration, with the phenyl ring sandwiched between two phenyl rings of one of the dppe ligands. The reaction of complexes 1 with 1 equiv of HBF4·Et2O leads to the formation of the very reactive hydride thiol complexes trans-[M(H)-(HSPh)(dppe)2]BF4 (M = Ru (2Ru), Os (2Os)). Analogous complexes to 1Os and 2Os with SC6H4-4-F instead of SPh are also described. In all cases there is no evidence for the existence of the tautomeric dihydrogen complex trans-[M(H2)(SAr)(dppe)2]+. In the presence of excess acid the diprotonated complex trans-[Os(H2)(HSPh)-(dppe)2](BF4)2 (3Os) is formed at 233 K where the T1(min) of the H2 ligand at 400 MHz is ～34 ms so that 0.98 ≤ dHH ≤ 1.24 A?. Under certain conditions the labile PhSH ligand of 3Os is substituted by water to give trans-[Os(H2)(OH2)(dppe)2](BF4) 2 (4Os). The thiol complexes 2 react rapidly with H2(g) to give the complexes trans[M(H2)H(dppe)2]BF4 (5Ru, 5Os). Complexes 3Os and 4Os also react with H2 to give 5Os. N2 and O2 (1 atm) displace the thiol in 2Os in CH2Cl2 to produce trans-[Os(H)(L)(dppe)2]+ (L = η1-N2 (6Os), η2-O2, (7Os)). trans-[Os(H)(O2)(dppe)2]OTf·3C6H 6 is characterized by X-ray diffraction.
Dihydrogen with frequency of motion near the 1H Larmor frequency. Solid-state structures and solution NMR spectroscopy of osmium complexes trans-[Os(H··H)X(PPh2CH2CH 2PPh2)2]+ (X = Cl, Br)
Maltby, Patricia A.,Schlaf, Marcel,Steinbeck, Martin,Lough, Alan J.,Morris, Robert H.,Klooster, Wim T.,Koetzle, Thomas F.,Srivastava, Ramesh C.
, p. 5396 - 5407 (2007/10/03)
A high-yield route to the new complexes OsBr2(dppe)2 and trans-OsHBr(dppe)2 starting from (NH4)2-[OsBr6] is described. The new 5-coordinate complexes [OsX(dppe)2]PF6 (X = Cl (80s) and X = Br (90s)) are prepared by reaction of cis-OsX2(dppe)2 with NaPF6. Complexes 80s and 90s consist of distorted trigonal bipyramidal cations with Y -shaped equatorial planes. They react in CH2Cl2 with H2 or HD (1 atm) to give complexes trans-[Os(H··H)X(dppe)2]PF6 (X = Cl (10sPF6), X = Br (20sPF6)) or trans-[Os(H··D)X(dppe)2]PF6, respectively. The last complexes have J(H,D) = 13.9 and 13.7 Hz, respectively. The BF4- salts of these complexes, 10sBF4 and 20sBF4, respectively, are prepared by reacting trans-OsHX(dppe)2 with HBF4·Et2O or DBF4·Et2O. These complexes are characterized by NMR, IR, and FAB MS. The single-crystal X-Yay and neutron diffraction studies of 10sPF6 revealed an elongated H··H ligand with dHH = 1.11(6) (X-ray) or 1.22(3) A?(neutron) occupying one site in an octahedral complex. The X-ray diffraction study of 20sBF4 produced a similar structure with dHH = 1.13(8) A?. One fluorine of the anion in each structure is positioned near the acidic H2 ligand. A linear relationship between dHH and J(H,D) for many dihydrogen complexes is used to indicate that complexes 10s and 20s have H-H distances of about 1.2 A? in solution. Plots of ln(Tl) versus inverse temperature for 10s and 20s are distorted from the usual V shape, suggesting that the rotational frequency of the H2 ligand is near that of the Larmor frequency. Therefore the dHH for 10s is between the values of 1.04 and 1.31 A? calculated from the Tl (min) for fast and slow spinning H2, respectively. The chloride ligand in trans-[Os(H··H)Cl(L)2]+ buffers the effect of changing the cis ligands L from dppe to depe to dcpe so that there is little change in the H-H distance. Complexes 10s and 20s have pKa values of 7.4 and 5.4, respectively, while trans-[Os(H2)H(dppe)2]+ is much less acidic with a pKa of 13.6. These pKa values and some E1/2 values are used to show that 10s and 20s are dihydride-like even though they have relatively short H-H distances. Properties of trans-[Os(H··H)Cl(depe)2]BF4 (30s) are also reported.
