The reactions of Cl with a series of linear alcohols: methanol (k1), ethanol (k2), 1-propanol (k3), 1-butanol (k4), and 1-pentanol (k5) were investigated as a function of temperature in the range of 264-382 K by laser photolysis-resonance fluorescence. The obtained kinetic data were used to derive the following Arrhenius expressions: k1=(3.55+/-0.22)x10(-10) exp[-(559+/-40)T], k2=(5.25+/-0.52)x10(-11) exp[(190+/-68)T], k3=(2.63+/-0.21)x10(-11) exp[(525+/-51)T], k4=(3.12+/-0.31)x10(-11) exp[(548+/-65)T], and k5=(3.97+/-0.48)x10(-11) exp[(533+/-77)T] (in units of cm(3) molecule(-1) s(-1)). To our knowledge, these are the first absolute kinetic data reported for 1-butanol and 1-pentanol and also the first kinetic study as a function of temperature for these two compounds. Results, mechanism, and tropospheric implications are discussed and compared with the reported reactivity with OH radicals. Moreover, a theoretical insight into the mechanisms of these reactions has also been pursued through ab initio Möller-Plesset second-order perturbation treatment calculations with 6-311G** basis sets. Optimized geometries and vibrational frequencies have been obtained for transition states and molecular complexes appearing along the different reaction pathways. Furthermore, molecular energies have been calculated at quadratic configuration interaction with single, double, and triple excitations level in order to get an estimation of the activation energies.

Citation for published item:worlD wF nd qr¡ %D qF nd qrz¡ onD eF nd qrndinoEold¡ nD tFwF nd poxD wFeF nd u(tD hFF nd e£ nsD eF nd welguizoD wF nd pern¡ ndezEq¡ omezD wF @PHIRA 9iletroni struture nd hrge trnsport properties of series of QDTE@diphenylAEsEtetrzine derivtives X re they suitle ndidtes for moleulr eletronisc9D tournl of physil hemistry gFD IIV @RTAF ppF PTRPUEPTRQWF Further information on publisher's website: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

The effect of fluorine substitution on the molecular structure, crystal packing, and n-type semiconducting properties of a set of poly(arylene-ethynylene) polymers based on alternating thiadiazole and phenyl units linked through ethynylene groups has been studied by means of Density Functional Theory. As a result, an enlargement in the interplanar distance between cofacial polymer chains, as well as a decrease of the electronic coupling and electron mobility is predicted. On the other hand, fluorination could facilitate electron injection into the material. A polymer containing both alkoxy pendant chains and fluorine atoms is proposed as a compromise solution between efficiency of electron injection and charge transport within the material.

No abstract

The effects of alkyl/alkoxy pendant chains on the electronic structure and properties of a typical poly(aryl-ethynylene) (PAE) system formed by phenylethynylene units and 1,3,4-thiadiazole rings are analyzed. Optical band gaps and electronic properties (electron affinity, LUMO energy and intramolecular reorganization energy) were computed for different oligomers and then estimated for a limit polymer. The electronic properties become more influenced by the nature of the lateral chain rather than by its length. The most significant changes in the electronic properties are obtained with alkoxy side chains. The smallest band gaps were calculated for polymers containing alkoxy pendant chains. A less favored electron injection is expected for polymers with higher energy values predicted for the LUMO levels and decrease of the electron affinity. Intramolecular reorganization energies computed for all studied polymers were rather low (≤0.07 eV), which allows them to be considered as candidates for n-type semiconductors.