Oxidative degradation of ethers promoted by strontium and barium tetraphenylimidodiphosphinates.

The novel M[(OPPh2)2N]2.nTHF (M = Sr (2), Ba (3)) complexes were prepared and characterized. Upon exposure to atmospheric oxygen, 2 and 3 were transformed to the dinuclear species Sr2-[(OPPh2)2N]4.2C3H6O3 (4) and Ba(2)[(OPPh2)2N]4.2C4H8O3 (5), respectively. Compounds 4 and 5 contain coordinated carboxylic acids obtained from the oxidative degradation of DME and THF, respectively, which were used as solvents for crystallization.