INTERLIGAND INTERACTIONS AFFECTING SITE-SPECIFIC METAL-BONDING - X-RAY CRYSTAL-STRUCTURES OF [RH2(ACETATO)4(L)2], WHERE L = 2,4-DIAMINO-6-METHYL-S-TRIAZINE, 2,6-DIMETHYL-4-AMINOPYRIMIDINE, AND 2,6-DIMETHYLPYRIDINE

Crystal structure analyses of [Rh2(OAc)4(L)2] (L = damt, dmap, dmp) ha ve shown that each heteroaromatic ligand (L) binds to the axial positi ons of the dirhodium-tetraacetate cage through the ring nitrogen N(3) but not N(1) for damt and dmap and N(1) for dmp. Interligand hydrogen bonding between the ring substituents adjacent to the nitrogen donor a nd the acetate oxygens determines the metal binding site, in accordanc e with their relative extent, N-H...O > C-H...O, where the latter is s till of considerable significance.