Selective preparation of twofold diorganophosphido-bridged metallatetrahedranes [Re-2(MPR3)(2)(mu-PR2)(2)(CO)(6)] with Re2M2 metal core (M = Au, Ag)

The reaction of the in situ prepared salt Li[Re-2(AuPR3')(mu-PR2)(CO)(7)Cl] (R = R' = Cy (1a), R = Cy, R' = Ph (1b), R = Ph, R' = Cy (1c), R = Ph, R' = Et (1d), R = Ph, R' = Ph (1e)) with one equivalent HPR2" in methanolic so lution at room temperature yields the neutral cluster complexes [Re-2(AuPR3 ')(mu-PR2)(CO)(7)(ax-HPR2") (R = R' = R " = Cy (2a), Ph (2b), R = R' = CL, R " = Et (2c), R = Cy, R' = R " = Ph (2d), R = Cy, R' = Ph, R " = Et (2e), R = R " = Ph, R' = Et (2f), R = Ph, R' = Cy, R " = Et (2g)). Photochemicall y induced these complexes react in the presence of the organic base DBU in TI-IF solution to give the doubly phosphido bridged anions Li[Re-2(AuPR3')( mu-PR2)(mu-PR2")(CO)(6)], which were characterized as salts PPh4[Re-2(AuPR3 ')(mu-PR2)(mu-PR2")(CO)(6)] (R = R' = R " = Ph (3a), R = R' = Ph, R " = Cy (3b), R = Ph, R' = Cy, R " = Et (3c), R = R " = Ph, R' = Et (3d)). These pr ecursor complexes 3 then react with one equivalent of ClMPR3' (M = Au, Ag) to doubly phosphido bridged metallatetrahedranes [Re-2(MPR3)(2)(mu-PR2)(mu- PR2")(CO)(6)] (M = Au, R = R' = R " = Ph (4a), M = Au, R' = Et, R = R " = P h (4b), M = Au, R = R' = Ph, R " = Cy (4c), M = Au, R = Cy, R' = Ph, R " = Et (4d), M = Ag, R = R' = R " = Ph (4e)). All isolated cluster complexes we re characterized and identified by the following analytical methods: NMR- ( H-1, P-31) and v(CO) IR-spectroscopy and, additionally, complexes 2b, 4a an d 4e by X-ray structure analysis.