Dechlorination of chlorinated ethylenes by a photochemically generated iron(0) complex.

The reactivity of Fe(0) toward chlorinated ethylenes was examined utilizing a photochemically generated, highly reactive Fe(0) complex. Irradiation of (dmpe)2FeH2 (dmpe = Me2PCH2CH2PMe2) with 360 nm light generated a 16-e(-), Fe(0) intermediate that reacted to dechlorinate chlorinated ethylenes in a stepwise fashion, consistent with a hydrogenolysis dechlorination pathway. The source of the hydrogen atoms in the hydrogenolysis were the hydride ligands of an additional equivalent of (dmpe)2FeH2, as evidenced by deuterium labeling experiments.

Photodegradation of the herbicide imazethapyr in aqueous solution: effects of wavelength, pH, and natural organic matter (NOM) and analysis of photoproducts.

The photodegradation of imazethapyr, 5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-4,5-dihydroimidazol-1H-3-yl)nicotinic acid, has been investigated in phosphate buffers and in buffered solutions containing natural organic matter (NOM). Imazethapyr degrades most quickly under 253.7 nm light and at pH values >4.