.eta.2-Dihydrogen on the brink of homolytic cleavage: trans-[Os(H.cntdot..cntdot..cntdot.H)H(PEt2CH2CH2PEt2)2]+ has spectroscopic and chemical properties between those of the isoelectronic complexes trans-[OsH(PPh2CH2CH2PPh2)2(.eta.2-H2)]+ and ReH3(PPh2CH2CH2PPh2)2

Abstract

H-'H coupling pattern may not be resolved, precluding the use of this method for assigning sugar pucker. Clearly, the 'H and 13C methods are complementary and both can be very useful. Finally, l3C signals are useful in defining metal-binding sites. The same advantages of this method for mononucleotide studies are passed on to oligonucleotide studies.25 Signals for carbons remote from the metal binding site appear to be most useful. discussions with Prof. David Live.

Synthesis, Molecular Structure and Catalytic Activity of Six‐Coordinate Chloro(hydrido)‐ and Dihydridoruthenium(II) and ‐osmium(II) Complexes with the Chiral Ligands PiPr2NH(Me)Ph, (S,S)‐Chiraphos and (S,S,)‐Diop

“…The T 1 (min) value for the well-characterized complex [OsH(H 2 )(dppe) 2 ] ϩ is 18 ms at Ϫ85°C. [17] In contrast to this species, which is dynamic and where an equilibration between the OsH and the Os(H 2 ) protons occurs at room temperature, a similar process could not be observed for 29. Whether this difference is a result of steric effects, that is, of the larger size of (S,S)-Chiraphos compared with dppe, is open to speculation.…”

1995 Alcan Award Lecture New intermediates in the homolytic and heterolytic splitting of dihydrogen

“…where v is the spectrometer frequency in MHz and Tlmin (slow) is in seconds (20). Unfortunately the dihydrogen ligand often has fast motion relative to 400 MHz and this makes the interpretation of TImin difficult.…”

New dihydrogen complexes: the synthesis and spectroscopic properties of iron(II), ruthenium(II), and osmium(II) complexes containing the meso-tetraphos-1 ligand

“…[5]. The yellow trans isomer has already been identified (27 small amount of the cis-P isomer is also identified in the reaction mixture by use of 3 1~ NMR (Table 1, see below).…”

“…A common reaction of the complexes trans-[M(H2)(H)L2]', M = Fe, Ru, 0 s and L = PEt2CH2CH2PEt2 (depe) and PPh2CH2CH2PEPh2 (dppe), is the intramolecular exchange of H atoms between the hydride and H2 sites (3)(4)(5)(6). To better understand this intramolecular hydrogen atom exchange, we have prepared new dihydrogen complexes of the tetradentate phosphine Ph2PCH2CH2P(Ph)CH2CH2P(Ph)CH2CH2-PPh2 (tet-1).…”