36 research outputs found
The proof of the pudding is in the eating: an outbreak of emetic syndrome after a kindergarten excursion, Berlin, Germany, December 2007
An outbreak of food poisoning (emetic syndrome) occurred in three kindergartens (A, B and C) in Berlin, Germany, on 3 December 2007 after an excursion during which food was served. We conducted a retrospective cohort study among the kindergarten children and personnel who participated in the trip. The overall attack rate among the 155 participants was 30%. It was 31% among the 137 children (aged two to six years) and 17% among adults (n=18). The consumption of rice pudding was significantly associated with disease. Among those who ate rice pudding, the attack rate was 36%, compared with 0% for non-eaters (relative risk: infinite,
The supramolecular architecture of arene complexes of bis(polyfluorophenyl)mercurials
The 1:1 (arene)mercury complexes [HgR2(arene)] [R = C6F4-o-NO2, C6F4-m-NO2, C6F4-o-H, C6F5; arene = TMB (1,2,4,5-tetramethylbenzene), PMB (1,2,3,4,5-pentamethylbenzene)] are readily formed when mixtures of the mercurial and arene are crystallised from CH2Cl2 or CH2Cl2/hexane. Analogous 1:1 complexes are also formed from Hg(C6F5)(2) and PhMe, whereas novel 1:2 complexes [HgR2(arene)(2)] result from Hg(C6F4-o-NO2)(2) and PhMe or TMO (1,2,4-trimethoxybenzene) and from Hg(C6F5)(2) and TMO. In the crystalline state, the 1:1 [HgR2(arene)] complexes exist as canted columns of alternating planar HgR2 and arene layers linked by weak (Hg center dot center dot center dot C 3.2-3.5 angstrom) eta(1) or eta(2) pi-arene-mercury interactions. For the TMB (R = C6F4-o-NO2, C6F4-o-H, C6F5) and PhMe (R = C6F5) complexes, the packing of neighbouring columns shows aligned, alternating fluoroarene and arene ring planes resulting in a 2D brick-wall motif with potential supramolecular components (fluoroarene-fluoroarene and fluoroarene-arene stacking). For the TMB complex with R = C6F4-m-NO2 the 2D array is distorted into a herringbone motif by weak C-H center dot center dot center dot O interactions. The 1:2 complex [Hg(C6F4-o-NO2)(2)-(PhMe)(2)] has an analogous mercury environment to the 1:1 complexes, and the packing shows a distinct layer structure of alternating rows of PhMe and HgR2 with two PhMe units per HgR2 unit but with no inter-stack interactions. The TMO complexes have long Hg center dot center dot center dot O contacts (3.2 angstrom.) rather than Hg center dot center dot center dot C and similarly show a layered structure, but in this case, with a single column of alternating HgR2 and pairs of TMO. Theoretical calculations for the 1:2 [HgR2(TMB)(2)] Complexes (R = C6F4-o-NO2, C6F4-m-NO2) are consistent with the findings from the observed crystal structures
Metal based synthetic routes to heavy alkaline earth aryloxo complexes involving ligands of moderate steric bulk
Synthesis of fluoro(aryloxo)alkaline earth metal cages by C–F bond activation\ud
Treatment of Ca or Sr metal with Hg(C6F5)2 and 2,4,6-trimethylphenol (HOmes) in 1,2-dimethoxyethane (dme) at room temperature resulted in C–F bond activation, giving rise to the unique fluoro(aryloxo)alkaline earth cages [Ca5(µ4-F)(µ3-F)4(µ-Omes)4(Omes)(dme)4] 1 and [Sr10(µ4-F)4(µ3-F)4(µ-Omes)12(dme)4] 2, which can be viewed as arrested fluorite structures