Deep-level transient spectroscopy (DLTS), photoluminescence (PL), and transmission electron microscopy (TEM) measurements have been made on n-type silicon after implanting with 5.6 MeV Si3+ ions using doses of 109–1014 cm−2 and anneals at 525 and 750 °C. In all the samples, there is only a small dependence of the widths and energies of the PL zero-phonon lines on implantation dose, allowing the high resolution of PL to be exploited. In samples annealed at 525 °C, the PL intensity can provide a measure of the concentration of defects over the implantation range, 109–1012 cm−2. Carbon-hydrogen complexes are identified as transient species with increasing dose, and the “T” center is related to a DLTS trap 0.20 eV below the conduction band energy Ec. At the highest doses in these samples, TEM imaging shows the presence of nanometer-sized clusters, and the PL spectra show that many previously unreported defects exist in the implanted zone, in addition to two broad bands centered on ∼885 and ∼930 MeV. The multiplicity of defects supports recent suggestions that a range of interstitial complexes is present in the annealed samples. Annealing at 750 °C produces complete recovery in both the DLTS and PL spectra for doses of less than 1013 cm−2. At higher doses, {113} self-interstitial aggregates are observed in TEM, along with the “903” PL signal associated with the {113} defects, and the Ec−0.33 eV “KA” DLTS trap. These data support the recent identification of that trap with the {113} defects. The well-resolved PL spectra show that many previously reported defects also exist in samples implanted with a dose of 1014 cm−2 and annealed at 750 °C, again implying the presence of a range of interstitial complexes.

The novel Pd-catalyzed C(sp(2))-H/C(sp(2))-H cross-coupling of unactivated xanthines with unactivated arenes utilizing a combination of Ag(I) and O(2) as oxidants exclusively yields C-8 arylated xanthines in a single synthetic operation.

The capacity of the mammalian olfactory system to detect an enormous collection of different chemical compounds is based on a large repertoire of odorant receptors (ORs). A small group of these ORs, the OR37 family, is unique due to a variety of special features. Members of this subfamily are exclusively found in mammals, they share a high degree of sequence homology and are highly conserved during evolution. It is still elusive which odorants may activate these atypical receptors. We have reasoned that compounds from skin, hairs, or skin glands might be potential candidates. We have exposed mice to such compounds and monitored activation of glomeruli through the expression of the activity marker c-fos in juxtaglomerular cells surrounding ventrally positioned glomeruli in the olfactory bulb (OB). Employing this methodology it was found that stimulation with long-chain alkanes elicits activation in the ventral part of the OB, however, none of the OR37 glomeruli. Analyses of long-chain hydrocarbon compounds with different functional groups revealed that long-chain aliphatic aldehydes elicited an activation of defined OR37 glomeruli, each of them responding preferentially to an aldehyde with different chain lengths. These results indicate that OR37 receptors may be tuned to distinct fatty aldehydes with a significant degree of ligand specificity.

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Depending on the ratio of the substrates and the reaction conditions, the Cu(I)-catalyzed domino reaction between bromobenzyl bromides and β-ketoesters exclusively yields either 4H-chromenes or naphthalenes.