A Binuclear Unsymmetrical Compartmental Ni^Ii Complex: [Μ-11,24-Dimethyl-16,19-Dioxa-3,7,15,20-Tetra-Aza-Tricyclo[20.3.1.1 ^9,13]Hepta-Cosa-1(25),2,7,9,11,13(27),14,20,22(26),23-Deca-Ene-26, 27-Diolato]Bis-[Diaqua-Nickel(Ii)] Bis(Per-Chlorate) Tetra-Hydrate