Premium
Protonation and Hydrogen Atom Abstraction Reactions in the Synthesis of the [HP 7 M(CO) 3 ] 2– Ions (M = Cr, W)
Author(s) -
Charles Scott,
Danis Janet A.,
Mattamana Sundeep P.,
Fettinger James C.,
Eichhorn Bryan W.
Publication year - 1998
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/(sici)1521-3749(199805)624:5<823::aid-zaac823>3.0.co;2-z
Subject(s) - triclinic crystal system , chemistry , protonation , crystallography , intramolecular force , ion , stereochemistry , hydrogen , ethylenediamine , hydrogen atom , crystal structure , inorganic chemistry , alkyl , organic chemistry
Ethylenediamine (en) solutions of [P 7 M(CO) 3 ] 3– (M = Cr, W) react with weak acids to give [HP 7 M(CO) 3 ] 2– ions where M = Cr ( 4 a ) and W ( 4 b ) in high yields. Competition studies with known acids revealed a pK a range for 4 b in DMSO of 17.9 to 22.6. The [P 7 M(CO) 3 ] 3– complexes also react with one‐half equivalent of I 2 to give 4 through an oxidation/hydrogen atom abstraction process. Labeling studies show that the abstracted hydrogen originates from the [K(2,2,2‐crypt)] + ions or from the solvent (DMSO‐d 6 ) in the absence of [K(2,2,2‐crypt)] + or other good hydrogen atom donors. In the solid state, the ions have no crystallographic symmetry but in solution they show virtual C s symmetry ( 31 P NMR spectroscopy) due to an intramolecular wagging process. Crystallographic data for [K(2,2,2‐crypt)] 2 [HP 7 W(CO) 3 ]: triclinic, P 1, a = 10.9709(8) Å, b = 13.9116(10) Å, c = 19.6400(14) Å, α = 92.435(6)°, β = 93.856(6)°, γ = 108.413(6)°, V = 2831.2(4) Å 3 , Z = 2, R(F) = 7.65%, R(wF 2 ) = 14.17% for all 7400 reflections. For [K(2,2,2‐crypt)] 2 [HP 7 Cr(CO) 3 ]: triclinic, P 1, a = 12.000(3) Å, b = 14.795(3) Å, c = 17.421(4) Å, α = 93.01(2)°, β = 93.79(2)°, γ = 110.72(2)°, V = 2877(2) Å 3 , Z = 2.