Photolysis of polyphosphate ions in alkaline aqueous solution

Photolysis of pyrophosphate and tripolyphosphate ions in aqueous solution is proposed to produce electron detachment with formation of pyrophosphate and tripolyphosphate radicals (with quantum yields <0.1 at 266 nm), respectively. Formation of P₂O₇^·3− is observed after photolysis of both polyphosphate ions, because the decomposition of P₃O₁₀^·4− yields P₂O₇^·3−. The latter radicals further react with hydroxyl ions (k = 1.4 × 10⁶ M⁻¹s⁻¹) generating HO^· radicals. The reaction of the solvated electrons with molecular oxygen produces O₂^·−. The rate constants for the reaction of SO₄^·− radicals with P₂O₇⁴⁻ and P₃O₁₀⁵⁻ were also measured. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 111–117, 2000