A-frame complex
In
dppm, and X and L are a wide variety of ligands. The term was coined to describe products arising from the oxidative addition to Rh(I)Rh(I) complexes.[1]
Scope of compounds
A-frame complexes typically consist of a pair of square-planar metal centres. Consequently, this family of complexes is found for those metals that tend to adopt that geometry, Rh, Ir, Ni, Pd, Pt, and Au. In addition to dppm, the analogous tetramethyldiphosphine (dmpm) also forms such complexes as do some related ligands, such as
NO, CH2, hydride
, and chloride.
(dppm)2.png)
Preparation
A frame complexes are often produced by the addition of reagents of the type AX2 to low valent complexes of dppm:
- 2 M(0) + AX2 + 2 dppm → M2(μ-A)(dppm)2X2
Alternatively the group "A" can be added across a preformed M-M bond, as indicated by the oxidative addition of elemental sulfur:[2]
- Pd2(dppm)2Cl2 + S → Pd2(μ-S)(dppm)2Cl2