Date of Award
Program or Major
Doctor of Philosophy
The synthesis, characterization and reactions of transition metal complexes containing diphosphine oxide, R(,2)P-P(O)PR(,2), and diphosphoxane, R(,2)P-O-PR(,2), ligands have been studied. The diphosphoxane tautomer, which is unstable in the free state has been observed to be stabilized by coordination to Mo(O) and Cu(I).
The reactivity of cis-(CO)(,4)Mo(R(,2)P-O-PR(,2)) (R = Ph, ptolyl) towards halogen-oxidation has been studied. The new seven-coordinate complexes (CO)(,3)Mo(R(,2)P-O-PR(,2))X(,2) (R = Ph, X = I; R = p-tolyl, X = Br), as well as the known (CO)(,3)Mo(Ph(,2)PCH(,2)PPh(,2))I(,2) have been observed to exhibit temperature dependent ('31)P NMR consistent with rapid topological isomerization and intramolecular rearrangement of a given isomer.
The reaction of coordinated aminophosphines has been shown to lead, via fluoride exchange, to mixed fluorophospine-aminophosphine complexes. This result is in agreement with published reports of fluoride exchange reactions which occur via initial coordination of BF(,3) etherate to the nitrogen donor of free aminophosphines.
The reaction of Ph(,2)P-P(O)Ph(,2) with cp(CO)(,2)FeTHF BF(,4) has resulted in a redistribution reaction leading to cp(CO)(,2)FePh(,2)P-PPh(,2)Fe(CO)(,2)cp BF(,4) (,2). A mechanism for this unusual transformation has been proposed based on(, )('31)P NMR evidence.
Five new complexes, cis-(CO)(,4)Mo(Ph(,2)P-O-PPh(,2)),cis-(CO)(,4)Mo(Ph(,2)P-O-P(O) (Ph)PPh(,2)), trans-(CO)(,4)Mo Ph(,2)P-P(O) (OEt)(,2)) (,2), (CO)(,3)Mo(Ph(,2)P-O-PPh(,2))I(,2), and (CuCl)(,2)Ph(,2)P-O-PPh(,2) (,2) have been structurally characterized by x-ray crystallography. ('31)P NMR and IR spectroscopy have been used extensively throughout the research described in this dissertation and the results of these spectroscopic investigations have been discussed.
Note: In this dissertation a convention will be used to simplify the drawing of metal carbonyl complexes. In this convention a.
will be used to represent a metal carbonyl. The above drawing is a representation of Mo(CO)(,6) in which the octahedral arrangement of the six carbon monoxide groups is shown simply as six lines radiating from the metal center. Substitution of carbon monoxide by a phosphine will be explicitly shown, ie.,
is a drawing of the complex trans-(CO)(,4)Mo(Ph(,2)PCl)(,2).
BRADLEY, FONTAINE COSBY, "THE SYNTHESIS, CHARACTERIZATION, AND REACTIONS OF DIPHOSPHINE MONOXIDE COMPLEXES OF SELECTED TRANSITION METALS" (1984). Doctoral Dissertations. 1439.