Cuprous and cupric complexes with the new imidazolyl containing tripodal tetradentate ligands {L MIm : (1H-imidazol-4-yl)-N,N-bis((pyridin-2-yl)methyl)methanamine, L EIm : 2-(1H-imidazol-4-yl)-N,N-bis((pyridin-2-yl)methyl)ethanamine} have been investigated to probe differences in their chemistry, especially in copper(I)-dioxygen chemistry, compared to that already known for the pyridyl analogue TMPA, tris(2-pyridyl)methyl)amine.

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Single crystals of a-iron were irradiated perpendicularly to the (100), (110), and (111)planes with electrons in the range 0.35 -1.7 MeV and their electrical resistivity change rates were measured. A geometrical model of the threshold-energy surface for atomic displacement in a bcc lattice produces a fit to the experimental data leading to the following values for the threshold energies in the principal crystal directions: Tz ' --17 + 1 eV, T""'~= 20+ 1.5 eV, and T""~30 eV. The specific resistivity of a Frenkel pair is deduced to pF"' --(30~5) p.Qcm/at. %%uo . From th eobtaine dT"'sw ederive da n interatomi cpotentia 1 of th eBorn-Maye r typ e, vali d in the range 1.2 & r & 2.5 A. We propose as a good choice: V(r) = 8900e "" eV. The recovery due to isochronal annealing during stage I, after irradiation at different electron energies, was measured and related to specific recovery mechanisms. Thus, the first important substage, I~(-66 K), is due to the recovery of close Frenkel pairs created in the (100) direction, while a comparison of calculated cross sections suggests that Ic (-87 K) possibly stems from (111)close pairs. Substage ID (90 -110 K) is complex; its first part, below 100 K, originates mostly from defects produced in the (100) direction and the second part, above 100 K, together with IE, principally originates from defects produced in the (111)direction.

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