Chemical properties Squaric acid

another, quantum mechanical, way of describing dianion assume π electrons of 2 double-bonded oxygen atoms shifted latter, 4 oxygens become single-bonded -o groups , double positive electric charge left in ring of carbon atoms. in way ring fits hückel s rule aromaticity (2 π-electrons = 4n + 2 n = 0). total symmetry of dianion consequence of charge distribution , aromaticity.