how to name these complex compounds in IUPAC? i am confused in assinging oxidation state to the central metal atoms, how to do that? see the attachment.

 For eg. complex particle: [CrCl2(H2O)4]+[CrCl2(H2O)4]+? 

We should begin by recognizing the ligands. The ligands here are Cl and H2O. In this manner, we will utilize the monodentate ligand names of "chloro" and "water". In order, water precedes chloro, so this will be their request in the mind boggling's name. There are 4 water's and 2 chloro's, so we will include the number prefixes before the names. Since both are monodentate ligands, we will state "tetra[aqua]di[chloro]". 

Since the ligands are named, we will name the metal . The metal is Cr, which is chromium. Along these lines, this coordination complex is called tetraaquadichlorochromium(III) particle.