Selective formation of rectangular grid coordination polymers with grid dimensions 10 x 15, 10 x 20 and 15 x 20 angstrom

Using four linear bifunctional ligands of different lengths and Ni(NO3)(2), three coordination polymers containing big rectangular cavities were shown to form selectively, despite the fact that all the four ligands are known to form square grid coordination polymers when they are reacted independent ly with M(NO3)(2).