Synthesis and Coordination Behavior of a New Hybrid Bidentate Ligand with Phosphine and Silylene Donors

This work describes the synthesis and coordination behavior of a new mixed‐donor ligand PhC(NtBu)(2)SiC(6)H(4)PPh(2) (1) containing both silylene and phosphine donor sites. Ligand 1 was synthesized from a reaction of ortho‐lithiated diphenylphosphinobenzene (LiC(6)H(4)PPh(2)) with chlorosilylene (PhC(NtBu)(2)SiCl). Treatment of 1 with Se and GeCl(2) resulted in Si(IV) compounds 2 and 3 by selective oxidation of the silylene donor. This strong σ‐donor ligand induces dissociation of CuCl and PhBCl(2) leading to formation of ionic complexes 4 and 5 respectively. The reaction of 1 with ZnCl(2) and AlCl(3) resulted in the formation of chelate complexes 5 and 7, respectively, while treatment with EtAlCl(2) and GaCl(3) forms monodentate complexes 8 and 9. X‐ray analysis of 4 showed that the copper is in the spiro center of the two five‐membered rings. Moreover, the copper(I)chloride has not been oxidized but dissociates to Cu(+) and [CuCl(2)](−). All the compounds are well characterized by mass spectrometry, elemental analysis, NMR spectroscopy, and single‐crystal X‐ray diffraction studies.