Various forms of linear dipyridyls in discrete rectangles, dinuclear rods, and one-dimensional networks containing(η5-pentamethylcyclopentadienyl)rhodium(III)

Cp* Rh(eta(1)- NO3)(eta(2)-NO3)] (1) reacted with pyrazine (pyz) to give a dinuclear complex [Cp* Rh(eta(1)- NO3)(mu-pyz)(0.5)](2). CH2Cl2 (3 . CH2Cl2). Tetranuclear rectangles of the type [Cp* Rh(eta(1),mu-X)(mu-L)(0.5)](4)(OTf)(4) (4a: X = N-3, L = bpy; 4b: X = N-3, L = bpe; 4c: X = NCO, L = bpy) were prepared from [Cp* Rh(H2O)(3)](OTf)(2) (2), a pseudo-halide (Me3SiN3 or Me3SiNCO), and a linear dipyridyl {4,4'-bipyridine (bpy) or trans-1,2-bis(4-pyridyl) ethylene (bpe)} by self-assembly through one-pot synthesis at room temperature. Treating complex 2 with NH4SCN and dipyridyl led to the formation of dinuclear rods, [Cp* Rh(eta(1)-SCN)(3)](2)(LH2) ( 5a: L = bpy; 5b: L = bpe), in which two Cp* Rh(eta(1)-SCN)(3) units are connected by the diprotonated dipyridyl (LH22+) through N+- H...N hydrogen bonds. Reactions of complex 2 with 1-(trimethylsilyl) imidazole (TMSIm) and dipyridyl (bpy or bpe) also produced another family of dinuclear rods [Cp* Rh(ImH)(3)](2) . L (6a: L = bpy; 6b: L = bpe). Treating 1 and 2 with TMSIm and NH4SCN (in the absence of dipyridyl) generated a 1-D chain [Cp* Rh(ImH)(3)](NO3)(2) (7) and a 1-D helix [Cp* Rh(eta(1)-SCN)(2)(eta(1)-SHCN)] . H2O (8 . H2O), respectively. The structures of complexes 3 . CH2Cl2, 4a . H2O, 4c . 2H(2)O, 5b, 6a, 7 and 8 . H2O were determined by X-ray diffraction.