X-Ray photoelectron spectroscopy (XPS) and radiotechnetium labelling of products from the reaction of tetrahydridoborate with transition metal salts

X-ray photoelectron Spectroscopy (XPS) was used to show that a black “boride”product arising from thermolysis of a non-aqueous copper borohydride solution contains boron in a surface-altered state, whereas similar cobalt, nickel and iron products prepared in water contain boron as the corresponding metal boride. A similar product prepared from CuSO₄ and NaBH₄ in water is known to be an effective carrier of radiotechnetium, as is that formed from copper borohydride. It is here shown that the products prepared from iron, cobalt or nickel salts are in fact more efficient radiotechnetium carriers than are the copper products.