PALLADIUM(II) COMPLEXES OF 3,3'-DIMETHYL-2,2'-BIINDAZOLE, 5,5'-DIMETHYL-2,2'-BIINDAZOLE, AND 7,7'-DIMETHYL-2,2'-BIINDAZOLE

Palladium-chelate complexes of the type [PdX2(L-L)] [X = Cl; L-L = 3,3'- (1), 5,5'- (2), or 7,7'-dimethyl-2,2'-biindazole (3) have been prepared, but are too insoluble for structural studies. When X = C6F5 the position of the methyl substituents is critical; thus, 3 is unable to give the corresponding complex due to severe methyl-C6F5 interactions, 2 gives a planar complex, and 1 gives a non-planar (likely helicene-type) complex due to methyl-methyl interaction, as shown by F-19 NMR spectroscopy. [Pd(C6F5)X(L-L)][X = Br; L-L = 1] is also non-planar.