The development of synthetic routes to complexes containing coordinate
d phosphorus monoxide, the analog of NO, is described, A series of ani
onic clusters [M-4(CO)(12)(mu(3)-PO)](-) (M = Ru, Os) as their [H2NPr2
i](+) and [Et4N](+) salts has been synthesized via the hydrolytic clea
vage of P-N bonds in the mu(3)-phosphinidene clusters M4(CO)(12)(mu(3)
-PNPr2i). The anion [OS4(CO)(13)(mu(3)-PO)](-) has also been prepared
from the corresponding phosphinidene cluster Os-14(CO)13(mu(3)-PNPr2i)
. Protonation of mu(3)-PNPr2i complexes by strong acid followed by tre
atment with base ([Et4N]OH or HNPr2i) provides access to hydroxyphosph
inidene complexes M-4(CO)(13)(mu(3)-POH) and the anions [M-4(CO)(13)(m
u(3)-PO)](-) (M = OS) or [M-4(CO)(12)(mu(3)-PO)](-) (M = Ru) The avail
ability of synthetic routes to PO complexes opens up opportunities to
explore the chemistry of coordinated PO ligands.