The photoluminescent and electroluminescent properties of conjugated polymers are, in part, controlled by interchain interactions in solid films. A study of the (chir)optical properties of optically active BMB‐PPV (see Figure) shows that circular dichroism spectroscopy is very powerful in detecting association of the polymer. Two different forms of BMB‐PPV are reported to be present in solution, depending on the solvent.

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The syntheses of (Z)-3,4,4-trimethyl-l-(triphenylstannyl)-l-pentene-3-ol ( 1) and (Z)-3,4,4trimethyl-l-(iododiphenylstannyl)-l-penten-3-ol (2) are reported. The solid-state structures of these tetra-and triorganotin compounds were determined by X-ray diffraction methods. The tin atom in 1 exists in a tetrahedral geometry distorted toward a trigonal bipyramidal one, with the distortion due to the close approach of the OH atom, i.e. 2.772(5) Á. A trigonal bipyramidal geometry is found in 2 where the oxygen atom, which forms significant 0-Sn interactions of 2.498(4) and 2.550(4) Á for the two independent molecules, respectively, is in an apical position as is the iodine atom. The different strengths of the HO-Sn interactions are related to the Lewis acidities of the respective tin centers. Crystals of 1 are triclinic, space group PI, with a = 11.120(6) k,b -11.652(6) k,c -9.998(5) Á, a = 110.15(5)°, ß -106.39(4)°, = 87.74(6)°, V = 1164(1) Á3, and Z = 2. Crystals of 2 are triclinic, space group PI, with a = 12.631(4) k,b = 13.887(1) k,c = 12.252(4) Á, a = 95.91(2)°, ß = 107.00(3)°, y = 74.67(2)°, V = 1981(1) Á3, and Z = 2. The structures were refined to final R -0.048 for 1 and R = 0.038 for 2. These compounds were characterized in solution by , 13C, and 119Sn NMR spectroscopy. The existence of an intramolecular HO-Sn coordination in solution was assessed by 13C and 119Sn secondary isotope multiplet of partially labeled entities (SIMPLE-NMR) experiments.

A kinetic model of plant nutrition described by Cloutier et al. (Cloutier et al., 2008. Biotechnol Bioeng 99:189-200) is progressively simplified so as to obtain a predictive model that describes the evolution of the biomass and the extracellular and intracellular concentrations of three determining nutrients, that is, free intracellular nitrogen, phosphate, and carbohydrate compounds. Three techniques of global sensitivity analysis are successively applied to assess the model parameter influence and potential correlation. The resulting dynamic model is able to predict plant growth for the two most encountered plant bioprocesses, namely suspension cells and hairy roots.