TY - JOUR
T1 - η1-Coordination of phosphinine to chromium, molybdenum, and tungsten
AU - Elschenbroich, Christoph
AU - Voss, Steffen
AU - Schiemann, Olav
AU - Lippek, Andrea
AU - Harms, Klaus
PY - 1998/9/28
Y1 - 1998/9/28
N2 - The homoleptic complexes hexakis(η1-phosphinine)molybdenum 10 and hexakisi(η1-phosphinine)tungsten 11 have been prepared via reduction of suitable metal halides with magnesium or zinc in order to explore trends in the triad (η1-C5H5E)6M, M = Cr, Mo, W. According to X-ray crystal structure determinations, 10 and 11 are isostructural and show almost ideal octahedral geometry of the metal - phosphorus core. The bond distances d(M-P) are relatively short in comparison to other homoleptic phosphane complexes of Mo and W; they follow the expected order: Cr-P (2.26 Å, 2) < Mo-P (2.38 Å, 10) ≈ W-P (2.37 Å, 11). The NMR data exhibit the same trends upon the η1-coordination of phosphinine as hexakis(η1-phosphinme)chromium 2, but the change of the central metal from Cr to W results in an increased shielding of the neighboring atoms (P, ortho-H, and C) of the ligands. The UV - vis spectra of 10 and 11 in comparison to 2 display a continuous hypsochromic shift in the MLCT region. Conversely, the redox potentials for the couples ML6(+/0), which are increasingly anodic following the sequence Cr < W < Mo, show a discontinuous gradation.
AB - The homoleptic complexes hexakis(η1-phosphinine)molybdenum 10 and hexakisi(η1-phosphinine)tungsten 11 have been prepared via reduction of suitable metal halides with magnesium or zinc in order to explore trends in the triad (η1-C5H5E)6M, M = Cr, Mo, W. According to X-ray crystal structure determinations, 10 and 11 are isostructural and show almost ideal octahedral geometry of the metal - phosphorus core. The bond distances d(M-P) are relatively short in comparison to other homoleptic phosphane complexes of Mo and W; they follow the expected order: Cr-P (2.26 Å, 2) < Mo-P (2.38 Å, 10) ≈ W-P (2.37 Å, 11). The NMR data exhibit the same trends upon the η1-coordination of phosphinine as hexakis(η1-phosphinme)chromium 2, but the change of the central metal from Cr to W results in an increased shielding of the neighboring atoms (P, ortho-H, and C) of the ligands. The UV - vis spectra of 10 and 11 in comparison to 2 display a continuous hypsochromic shift in the MLCT region. Conversely, the redox potentials for the couples ML6(+/0), which are increasingly anodic following the sequence Cr < W < Mo, show a discontinuous gradation.
UR - http://www.scopus.com/inward/record.url?scp=0005363854&partnerID=8YFLogxK
U2 - 10.1021/om9804879
DO - 10.1021/om9804879
M3 - Article
AN - SCOPUS:0005363854
SN - 0276-7333
VL - 17
SP - 4417
EP - 4424
JO - Organometallics
JF - Organometallics
IS - 20
ER -