21. The anions and should also be able to exist in aqueous solution. 22. Both dioxygen and the superoxide anion are free radicals that exhibit paramagnetism. 23. Polyoxomolybdates include the wheel-shaped molybdenum blue anions and spherical keplerates. 24. The anion has T h ( idealized O h ) molecular symmetry. 25. When dissociated, the diisopropylamide anion can become protonated to form Diisopropylamine. 26. Tetrafluoroborate salts are commonly employed as non-coordinating anions . 27. Ionophores selective for cations and anions have found many applications in analysis. 28. This yellow-orange solid is a salt of the superoxide anion . 29. Diperiodatonickelate anions in alkaline solution can oxidise bromate to perbromate. 30. The voltage dependent anion channel of the mitochondrion is also up regulated.