N,P‐Coordination of an Amino(imino)phosphane

Abstract

the lability of Pv-Teri compounds (tellurium atom transfer between phosphanes)"]. Thus, we have recently shown that tellurium can be inserted into the P-Si bond of di-tertbutyl(trimethylsily1)phosphane la, but is incapable of inducing a further oxidation of the tellurophosphinite 2a['"'. The insertion product merely equilibrates with the symmetrically substituted tellurium compounds 3 and 4. We have now found that when a less bulky silylphosphane is used as starting material, a novel P-P coupling by detelluration (3 -f 5) follows the reaction steps 1 + 2 and 2 -, 3 + 4 : diphenyl(trimethylsily1)phosphane l b reacts smoothly with tellurium to give tetraphenyldiphosphane 5b and bis(trimethylsilyl) telluride 4. + 2 Te 3 li2PSiAle3 -d 2 RzP-le-SiR.le3 l a , It = t H u l b . K = P h 2 \ 11 z P -1~~ -PK2 + hIe3Si-'I'e-Si >,I e3 [Z 456 IE] German version: Angew. Chem. 95 (1983) 1003Angew. Chem. Znr. Ed. Engl. 22 (1983) No. I 2 0 Verlug Chemie GmbH.

P–C, P–N, and M–N Bond Formation Processes in Reactions of Heterometallic Phosphinidene-Bridged MoMn and MoRe Complexes with Diazoalkanes and Organic Azides to Build Three- to Five-Membered Phosphametallacycles

“…70% yield after chromatographic workup). The latter displays a bridging phosphaimine (or iminophosphinidene) ligand in a rare κ P :κ N coordination mode (Scheme ), previously identified only in the rhenium complex [Re 2 (μ-Br) 2 {μ-κ P :κ N -P­(N i Pr 2 )­N­( t Bu)}­(CO) 6 ] . We note the specific ligation of P to the Mo atom and the NR nitrogen to the Re atom, thus retaining most of the connections in the parent compound 3a.2 .…”

“…As for the coordination of the bridging ligand, we note that the Re–N separation of 2.205(2) Å is close to the reference figure of ca. 2.22 Å for a single bond between these atoms, actually very close to the corresponding distance measured in the mentioned complex [Re 2 (μ-Br) 2 {μ-κ P :κ N -P­(N i Pr 2 )­N­( t Bu)}­(CO) 6 ] (2.21(2) Å) . In contrast, the Mo–P distance of 2.3081(7) Å is significantly shorter than the values of around 2.45 Å typically found for phosphines bound to molybdenum (for instance, ca.…”

“…2.22 Å for a single bond between these atoms, 19 actually very close to the corresponding distance measured in the mentioned complex [Re 2 (μ-Br) 2 {μ-κ P :κ N -P(N i Pr 2 )N( t Bu)}(CO) 6 ] (2.21(2) Å). 21 In contrast, the Mo–P distance of 2.3081(7) Å is significantly shorter than the values of around 2.45 Å typically found for phosphines bound to molybdenum (for instance, ca. 2.44 Å in [Mo 2 Cp 2 (CO) 4 (μ-Ph 2 PCH 2 PPh 2 )]), 23 it being actually comparable to the values of ca.…”

“…The latter displays a bridging phosphaimine (or iminophosphinidene) ligand in a rare κ P :κ N coordination mode ( Scheme 5 ), previously identified only in the rhenium complex [Re 2 (μ-Br) 2 {μ-κ P :κ N -P(N i Pr 2 )N( t Bu)}(CO) 6 ]. 21 We note the specific ligation of P to the Mo atom and the NR nitrogen to the Re atom, thus retaining most of the connections in the parent compound 3a.2 . No evidence for the formation of an alternative isomer of 4a (with P -binding of the bridging ligand to Re, and N -binding to Mo) was obtained in this denitrogenation reaction.…”