 It is a tetravalent basic (cationic) dye with a copper (Cu2+, coordination 4 of 6, orbital configuration d9 with Jahn–Teller distortion) phthalocyanine nucleus (CuPc) with three or four pendent isothiouronium side chains imparting its bulkiness and positive charges.In order to qualify as an alcian blue family member there has to be at least 2 side chains and the mixtures often have 3 chains in average to qualify as 8G.Four tetramethylisothiouronium groups per molecule are shown in the picture.