Large-ring complexes of platinum and palladium of the type trans-[{MCl2[But 2P(CH2) n PBut 2]} x ]

Trans-chelating diphosphines, the elusive ligands!

“…When 4 ] in order to promote the halide dissociation (and cyclometallation), a new dicationic dimeric species was isolated. Crystals of this compound suitable for X-ray diffraction were obtained showing a peculiar structure (Scheme 7) and proves that ligand 6 can accommodate the two phosphorus atoms at distances as large as 6.6Á [88]!…”

“…Obviously, in addition to cis-ligands, trans-chelating diphosphines seemed an obvious target as well. Initial backbones consisted of simple long hydrocarbon chains, but the possibility of different coordination modes and oligomer formation rendered somewhat disappointing results [1][2][3][4]. A more promising option arrived at this early stage with a more sophisticated phenanthrene based backbone developed by Venanzi et al [5].…”

Using the 1,2‐dihydro‐1,2‐diphosphinine ring as a template for the synthesis of new bicyclic structures and new trans‐chelating bis‐phosphines

“…These long-chain ␣, -bis-phosphines are known to favor the formation of transsquare planar complexes with Pd(II) and Pt(II) for conformational and entropic reasons [4,5]. Thus, the formation of the trans-[PdCl 2 (10)] complex (11) was not unexpected (Eq.…”

Cooperative Catalysis with First‐Row Late Transition Metals

“…[35] Many variations of these rigid, meridional tridentate ligand scaffolds have been developed, including many that do not exhibit rigid pincerlike binding characteristics but induce a more flexible coordination sphere around the metal center of choice. [36] The original design featured a central (pivotal) deprotonated sp 2 carbon flanked by two heteroatom donor groups, but over the years various other classes have emerged, the latest being EBE with a deprotonated boryl group.…”