Copper(I) and copper(II) compounds of a dinucleating, octadentate tetrakisbenzimidazole ligand. Crystal and molecular structures of three dihalogeno{1,8-bis[bis(1′-methylbenzimidazol-2′-ylmethyl)amino]-3,6-dioxaoctane}dicopper(II) bis(anion) compounds (halogen = F, Cl, or Br; anion = BF4, CF3SO3, or