Flash Flood simulation and valve behavior of Mytilus galloprovincialis measured with Hall sensors

Mussels close their shell as a protective strategy and the quantification of this behavioral marker may represent an alarm signal when they are exposed to environmental stressors. In the present study, we investigated the ability of the Mediterranean mussel Mytilus galloprovincialis to recover and then the resilience or inertia of valve activity after a pulsing exposition to diverse levels of salinity (5, 10, 20 and 35 PSU as reference value). The trial simulated an event of drastic and sudden reduction of seawater salinity thus mimicking an event of Flash Flood from intense rain. Valve gaping and movements were measured in continuous cycle for ten days using a customized magneto-electric device which uses Hall sensors. Results showed that under normal conditions of salinity (35 PSU) the general pattern of valve movements was a continuously open state with sporadic spikes indicating a closing motion. At salinity of 5 PSU mussels reacted by closing their valves, leading to a 77% mortality on the fourth day. At salinity of 10 PSU animals were observed with closed valves for the entire duration of the exposure and no mortality occurred, they showed a significant reduction in the valve activity once the reference value of salinity was re-established. In contrast, salinity of 20 PSU did not trigger a significant behavioral response. Interestingly, there no define rhythms of valve movements were recorded during salinity challenges

Association of poly(tetrathiafulvalenylethynyl)benzenes in neutral and cationic states

We synthesized a series of poly(tetrathiafulvalenylethynyl)benzenes and investigated their association properties in neutral and cationic states. The association constants of 1a and 2a with butylthio substituents in CDCl$_{3}$ solution are 1.4 M$^{-1}$ and 11.0 M$^{-1}$ at 20°C, respectively. Cationic species derived from 1, 2 and 3 more easily aggregate in solution. The cation radicals prepared by doping of 1 and 2 with iodine show electrical conductivities as semiconductors. Key words. TTF - association - mixed valence state - $\pi$ dimer – conductivity.

Interaction and aggregation of TTF oligomers towards supramolecular chemistry

Dimeric and oligomeric TTFs have an inherent multi-functionality. Thus, radical salts derived from bi-TTF and its derivatives show high conductivities, reflecting either the enhancement of dimensionality or the control of stoichiometry. In the case of TTF oligomers, supramolecular structures can be constructed using association of TTFs. Thus, quarter-TTF adopts a zigzag structure, and its tetracation forms a helical structure through the intramolecular $\pi$-dimer formation of the terminal radical cations. Poly(tetrathiafulvalenylethynyl)benzenes dimerize in solutions, and tetrathiafulvalenylacetylene macrocycles containing TTF and hexadehydro[12]annulene units show interesting properties such as solvatochromism, electrochromism, sandwitch complex formation, and electrical conductivities. Key words. TTF dimers – TTF oligomers – quarter TTF – dimensionality – supramolecular structure – poly(tetrathiafulvalenylethynyl)benzenes – tetrathiafulvalenylacetylene macrocycles

Strong π{\pi }-d interaction based on brominated TTF-type donor EDT-TTFBr2{_{2}}

New $\pi$-$d$ interacting system based on brominated TTF-type donor EDT-TTFBr$_{2}$ (= 4,5-dibromo-4$^\prime$,5$^\prime$-ethylenedithiotetrathiafulvalene) was investigated. Magnetic (EDT-TTFBr$_{2})_{2}$FeBr$_{4}$ and non-magnetic (EDT-TTFBr$_{2})_{2}$GaBr$_{4}$ are isostructural salts, which have strong anion-donor interaction through Br-Br atomic contacts with weak direct anion-anion interaction. The iron salt takes an antiferromagnetic transition at $T_{N}$ = 11 K owing to strong $\pi$-$d$ interaction, which originates from the strong anion-donor interaction. The strong $\pi$-$d$ interaction also plays an important role in the electron transport phenomenon in the variation of temperature and applied magnetic field. Key words. $\pi$-$d$ interaction - negative magnetoresistance - organic magnetic conductor