Reference

Triplet-singlet resonance energy transfer in commercial polypropylene

Triplet-singlet resonance energy transfer in commercial polypropylene. Homer, John; McKellar, John F. (Dep. Chem. Appl. Chem., Univ. Salford, Salford, Engl.). Chem. Ind. (London), (4), 158-9 (English) 1977. CODEN: CHINAG. DOCUMENT TYPE: Journal CA Section: 35 (Synthetic High Polymers) Polypropylene [9003-07-0] doped with 9.0 .times. 10-3M 9,10-dibromoanthracene [523-27-3] showed only the fluorescence emission of the dibromoanthracene. Polypropylene films contg. a range of dibromoanthracene concns., such that phosphorescence of photoactive chromophoric species already present in the polypropylene could still be obsd., were irradiated and the sum of all mean lifetimes calcd. at 10 mm internals in the range 390-520 nm foreach dibromoanthracene concn. The exptl. crit. transfer distance for triplet-singlet resonance energy transfer thus detd. was .apprx.15 nm, demonstrating that resonance, and not exchange, was the mechanism responsible for donor-acceptor energy transfer in the polypropylene.

Phosphoric acid systems

Phosphoric acid systems. Part 7. The halogenation or nitration of aryl compounds in trialkyl phosphates. Pearson, D. E.; Frazer, M. G.; Frazer, V. S.; Washburn, L. C. (Dep. Chem., Vanderbilt Univ., Nashville, Tenn.In this article, certain chemicals are used. Some of their cas registry numbers are 523-27-3 and 16218-28-3 , USA). Synthesis, (9), 621-3 (English) 1976. CODEN: SYNTBF. DOCUMENT TYPE: Journal CA Section: 26 (Condensed Aromatic Compounds) Section cross-reference(s): 25 No H halide is evolved during halogenation of arom. compds. in (MeO)3PO (I) as a solvent; thus, substances which are sensitive to H halide are more amenable to halogenation in I. 1,3,5-(Me3C)3C6H3 on bromination under ordinary circumstances with Br in CCl4 gives a dealkylation product, with Br in AcOH gives no reaction, but with Br in I gives 2,4,6-(Me3C)3C6H2Br in 59% yield (90% crude yield). Br or Cl in I are quite mild reagents capable of substitution into nuclei as active as, or more reactive than, C6H6. Iodination can be carried out on less active substrates with ICl but with iodine itself on phenols. Among other arom. compds. halogenated in I were phenanthrene, its derivs., fluorene, and thiophene. On nitration in I, anthracene gave 9-nitroanthracene (71% yield) and 9-methylphenanthrene gave 9-methyl-10-nitrophenanthrene (37% yield). .