Benzothieno[3,2‐b]benzothiophene (BTBT) is an excellent organic transistor material, and its charge‐transfer salt (BTBT)2PF6 is an organic metal that exhibits conductivity as high as 1500 S cm–1 at room temperature. Here, we report a charge‐transfer salt of the selenium analogue, benzoseleno[3,2‐b]benzoselenophene (BSBS). (BSBS)2TaF6 is a one‐dimensional metal isostructural to (BTBT)2PF6. The resistance jump temperature is reduced from 150 to 90 K, and the increase of the low‐temperature resistivity is largely diminished. However, the spin susceptibility shows an obvious drop below 50 K, which implies that the low‐temperature ground state is essentially a singlet state.

Structural, transport, and magnetic properties of new organic conductors composed of (BEDT-TTF) 2 TaF 6 , where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene, have been investigated. Two δ-type polymorphs, monoclinic and orthorhombic phases are obtained by the electrocrystallization. Both phases show a semiconductor-insulator phase transition at 276 K and 300 K for the monoclinic and orthorhombic phases, respectively; the ground state of both salts is a nonmagnetic insulating state. The low-temperature X-ray diffraction measurements show two-fold superlattice reflections in the intercolumnar direction. The low-temperature crystal structures show a clear charge ordered state, which is demonstrated by the molecular shape and intramolecular bond lengths. The observed checkerboard charge ordered state is in agreement with the charge ordering in a dimer Mott insulator. If we distinguish between the monoclinic and orthorhombic phases, the transition temperature of the δ-type (BEDT-TTF) 2 MF 6 conductors (M = P, As, Sb, and Ta) increases continuously with increasing the anion volume.

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In Shizuoka Prefecture, Japan, glyphosate-resistant Lolium multiflorum is a serious problem on the levees of rice paddies and in wheat fields. The mechanism of resistance of this biotype was analyzed. Based on LD 50 , the resistant population was 2.8-5.0 times more resistant to glyphosate than the susceptible population. The 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPS) gene sequence of the resistant biotype did not show a non-synonymous substitution at Pro106, and amplification of the gene was not observed in the resistant biotype. The metabolism and translocation of glyphosate were examined 4 days after application through the direct detection of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) using liquid chromatograph-tandem mass spectrometer (LC-MS/MS). AMPA was not detected in either biotype in glyphosate-treated leaves or the other plant parts. The respective absorption rates of the susceptible and resistant biotypes were 37.90 AE 3.63% and 41.09 AE 3.36%, respectively, which were not significantly different. The resistant biotype retained more glyphosate in a glyphosate-treated leaf (91.36 AE 1.56% of absorbed glyphosate) and less in the untreated parts of shoots (5.90 AE 1.17%) and roots (2.76 AE 0.44%) compared with the susceptible biotype, 79.58 AE 3.73%, 15.77 AE 3.06% and 4.65 AE 0.89%, respectively. The results indicate that the resistance mechanism is neither the acquisition of a metabolic system nor limiting the absorption of glyphosate but limited translocation of the herbicide in the resistant biotype of L. multiflorum in Shizuoka Prefecture.

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