Platinum and rhodium complexes with isoleucinol-based bi- and tricyclic hydrophosphoranes

The complex formation of bi- and tricyclic hydrophosphorane derivatives of isoleucinol with Pt(COD)Cl₂], Rh(CO)₂Cl]₂, and Rh(THF)₂(COD)]⁺BF₄ ^– (COD is cycloocta-1,5-diene) was investigated. In all cases, bicyclic hydrospirophosphorane selectively forms the metal chelates M(²-PN)(X)Cl] (M = Pt, X = Cl; M = Rh, X = CO) and Rh(²-PN)(COD)]⁺BF₄ ^–. («» denotes the residue of the hydrospirophosphorane ligand, which does not contain the P and N atoms). In addition, tricyclic hydrophosphorane (L) generates the phosphoranide complexes Pt(¹-L)(COD)Cl]⁺Y^– (Y = Cl or BF₄). The structures of the new compounds were established by IR spectroscopy, ³¹P, ¹³C, ¹H, ²H, ¹¹B, ¹⁹F, and ¹⁹⁵Pt NMR spectroscopy, and plasma-desorption and electrospray ionization mass spectrometry. The possible mechanism of coordination of hydrophosphoranes is discussed.