Collect. Czech. Chem. Commun. 1997, 62, 1888-1904

Multinuclear NMR Studies of Palladium(II) Dihalide Complexes of Dibutyl {α-[4-(Phenyldiazenyl)anilino]benzyl}phosphonate

Ljerka Tušek-Božica, Manda Curica, Dražen Vikic-Topica and Antonín Lyčkab

a Department of Chemistry, Ruđer Bošković Institute, Bijenicka 54, 10000 Zagreb, Croatia
b Research Institute of Organic Syntheses, 532 18 Pardubice-Rybitví, Czech Republic


The 1H, 13C, 15N and 31P NMR studies of two types of palladium(II) dihalide complexes of dibutyl {α-[4-(phenyldiazenyl)anilino]benzyl}phosphonate (L) are reported: those with the monodentate trans-bonded ligands through the azo nitrogen, trans-Pd(L)2X2 (X = Cl, Br), and a cyclopalladated binuclear complex in which chloride ions bridge two metal centers, [Pd(L-H)(μ-Cl)]2. The 15N-enriched organophosphorus compound and its palladium(II) complexes were also prepared to enable unambiguous determination of the nitrogen ligation site by 15N NMR. The NMR analysis was accomplished by one- and two-dimensional homo- and heteronuclear experiments including 1H-1H COSY, long-range 1H-1H COSY, NOESY, 1H-13C COSY, long-range 1H-13C COSY, HMQC and HMBC. With the mononuclear complexes, the formation of isomeric species was observed, which are interpreted as rotational isomers caused by restricted rotation around the metal-ligand bond.

Keywords: Chelates; Phosphonates; Aminophosphonate ligands; Palladium complexes; 1H, 13C, 15N and 31P NMR spectroscopy; Two-dimensional NMR.