Gravar-mail: μ-Acetato-κ(2) O:O′-[7,23-dibenzyl-15,31-dichloro-3,7,11,19,23,27-hexa­azatri­cyclo­[27.3.1.1(13,17)]tetra­triconta-1(32),2,11,13,15,17(34),18,27,29(33),30-deca­ene-33,34-diolato-κ(10) N (4),N (5),N (6),O (1),O (2):N (1),N (2),N (3),O (1),O (2)]dinickel(II) per­chlorate acetonitrile disolvate