Ancillary Ligand Lability Improves Control in Cyclic Ruthenium Benzylidene Initiated Ring-Expansion Metathesis Polymerizations.

The synthesis of well-defined cyclic polymers is crucial to exploring applications spanning engineering, energy, and biomedicine. These materials lack chain-ends and are therefore imbued with unique bulk properties. Despite recent advancements, the general methodology for controlled cyclic polymer synthesis via ring-expansion metathesis polymerization (REMP) remains challenging. Low initiator activity leads to high molar mass polymers at short reaction times that subsequently "evolve" to smaller polymeric products. In this work, we demonstrate that in situ addition of pyridine to the tethered ruthenium-benzylidene REMP initiator CB6 increases ancillary ligand lability to synthesize controlled and low dispersity cyclic poly(norbornene) on a short time scale without relying on molar mass evolution events.

Autochthony and isotopic niches of benthic fauna at shallow-water hydrothermal vents.

The food webs of shallow-water hydrothermal vents are supported by chemosynthetic and photosynthetic autotrophs. However, the relative importance of these two basal resources for benthic consumers and its changes along the physicochemical gradient caused by vent plumes are unknown. We used stable carbon and nitrogen isotopes (i.e., δ13C and δ15N) and Bayesian mixing models to quantify the dietary contribution of basal resources to the benthic fauna at the shallow-water vents around Kueishan Island, Taiwan. Our results indicated that the food chains and consumer production at the shallow-water vents were mainly driven by photoautotrophs (total algal contribution: 26-54%) and zooplankton (19-34%) rather than by chemosynthetic production (total contribution: 14-26%). Intraspecific differences in the trophic support and isotopic niche of the benthic consumers along the physicochemical gradient were also evident. For instance, sea anemone Anthopleura sp. exhibited the greatest reliance on chemosynthetic bacteria (26%) and photoautotrophs (66%) near the vent openings, but zooplankton was its main diet in regions 150-300 m (32-49%) and 300-700 m (32-78%) away from the vent mouths. The vent-induced physicochemical gradient structures not only the community but also the trophic support and isotopic niche of vent consumers.

A Cyclic Ruthenium Benzylidene Initiator Platform Enhances Reactivity for Ring-Expansion Metathesis Polymerization.

Ring-expansion metathesis polymerization (REMP) has shown potential as an efficient strategy to access cyclic macromolecules. Current approaches that utilize cyclic olefin feedstocks suffer from poor functional group tolerance, low initiator stability, and slow reaction kinetics. Improvements to current initiators will address these issues in order to develop more versatile and user-friendly technologies. Herein, we report a reinvigorated tethered ruthenium-benzylidene initiator, CB6, that utilizes design features from ubiquitous Grubbs-type initiators that are regularly applied in linear polymerizations. We report the controlled synthesis of functionalized cyclic poly(norbornene)s and demonstrate that judicious ligand modifications not only greatly improve kinetics but also lead to enhanced initiator stability. Overall, CB6 is an adaptable platform for the study and application of cyclic macromolecules via REMP.

Synthesis of the diketopyrrolopyrrole/terpyridine substituted carbazole derivative based polythiophenes for photovoltaic cells.

A series of conjugated polythiophenes (PTs) having low band gap energies (PDPP, PDPCz21, PDPCz11), with 2-ethylhexyl-functionalized 2,5-thienyl diketopyrrolopyrrole (TDPP) as the electron acceptor and terpyridine-substituted carbazole (TPCz) as the electron donor, have been synthesized and studied for their applicability in polymer-based photovoltaic cells (PVCs). The thermal stability and solvent solubility of PTs increased upon increasing the content of the TPCz derivative. PVCs were fabricated having the following architecture: indium tin oxide/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate/PT:6,6-phenyl-C71-butyric acid methyl ester (PC71BM)/Ca/Ag. The compatibility between the PT and PC71BM improved upon increasing the TPCz content. The photovoltaic properties of the PDPCz21-based PVCs were superior to those of their PDPP- and PDPCz11-based counterparts.

Mathematical modeling suggests high potential for the deployment of floating photovoltaic on fish ponds.

Rising energy needs and pressure to reduce greenhouse gas emissions have led to a significant increase in solar power projects worldwide. Recently, the development of floating photovoltaic (FPV) systems offers promising opportunities for land scarce areas. We present a dynamic model that simulates the main biochemical processes in a milkfish (Chanos chanos) pond subject to FPV cover. We validated the model against experimental data collected from ponds with and without cover during two production seasons (winter and summer) and used it to perform a Monte-Carlo analysis of the ecological effects of different extents of cover. Our results show that the installation of FPV on fish ponds may have a moderate negative impact on fish production, due to a reduction in dissolved oxygen levels. However, losses in fish production are more than compensated by gains in terms of energy (capacity of around 1.13 MW/ha). We estimated that, with approximately 40,000 ha of aquaculture ponds in Taiwan, the deployment of FPV on fish ponds in Taiwan could accommodate an installed capacity more twice as high as the government's objective of 20 GW solar power by 2025. We argue that the rules and regulations pertaining to the integration of FPV on fish ponds should be updated to allow realizing the full potential of this new green technology.

Globospongicola jiaolongi Jiang, Kou & Li, 2015, a junior subjective synonym of G. spinulatus Komai & Saito, 2006 (Crustacea: Decapoda: Stenopodidea: Spongicolidae).

Morphological and genetic analyses both showed that the abundant material of deep-sea sponge associated Globospongicola shrimps collected off southwestern Taiwan belongs to the same species as G. spinulatus Komai & Saito, 2006 described from the Southwest Pacific and G. jiaolongi Jiang, Kou & Li, 2015 recently described from the South China Sea. Thus, G. jiaolongi is treated as a junior subjective synonym of G. spinulatus. Moreover, it is confirmed that G. spinulatus inhabits general deep-sea area but not in chemosynthetic environment.

First records of Lithodes longispina Sakai, 1971 (Crustacea: Decapoda: Anomura: Lithodidae) from southwestern Taiwan, including a site in the vicinity of a cold seep.

Lithodid crabs (Lithodidae Samouelle, 1819), commonly known as king crabs, are frequent targets of commercial fishing worldwide with most of them living in deep water (Sakai 1971; Ahyong et al. 2010). Lithodes Latreille, 1806, is the second largest genus of lithodid crabs, currently including 29 species worldwide (Ahyong 2010). In Taiwanese waters, however, only two species, L. turritus Ortmann, 1892, and L. formosae Ahyong & Chan, 2010, have been reported (Wu et al. 1998; Ahyong & Chan 2010; Ahyong et al. 2010). We report herein the discovery of L. longispina Sakai, 1971, previously known reliably only from Japan (Sakai 1971; Ikeda 1998; Ahyong 2010), from off southwestern Taiwan, including a specimen collected in the vicinity of a cold seep.

Community Structure of Macrobiota and Environmental Parameters in Shallow Water Hydrothermal Vents off Kueishan Island, Taiwan.

Hydrothermal vents represent a unique habitat in the marine ecosystem characterized with high water temperature and toxic acidic chemistry. Vents are distributed at depths ranging from a few meters to several thousand meters. The biological communities of shallow-water vents have, however, been insufficiently studied in most biogeographic areas. We attempted to characterize the macrofauna and macroflora community inhabiting the shallow-water vents off Kueishan Island, Taiwan, to identify the main abiotic factors shaping the community structure and the species distribution. We determined that positively buoyant vent fluid exhibits a more pronounced negative impact to species on the surface water than on the bottom layer. Species richness increased with horizontal distance from the vent, and continuing for a distance of 2000 m, indicating that the vent fluid may exert a negative impact over several kilometers. The community structure off Kueishan Island displayed numerous transitions along the horizontal gradient, which were broadly congruent with changes in environmental conditions. Combination of variation in Ca2+, Cl-, temperature, pH and depth were revealed to show the strongest correlation with the change in benthic community structure, suggesting multiple factors of vent fluid were influencing the associated fauna. Only the vent crabs of Kueishan Island may have an obligated relationship with vents and inhabit the vent mouths because other fauna found nearby are opportunistic taxa that are more tolerant to acidic and toxic environments.

First record of the Nephropid genus Acanthacaris Bate, 1888 (Crustacea: Decapoda: Nephropidae) from Taiwan.

The giant deep-sea lobster genus Acanthacaris Bate, 1888 is reported for the first time from Taiwan. The single specimen with a total length of 36 cm was collected near a cold seep off southwestern Taiwan at about 1300 m deep and identified as A. tenuimana Bate, 1888.

Microwave-assisted benzyl-transfer reactions of commercially available 2-benzyloxy-1-methylpyridinium triflate.

Benzylation of alcohols and other substrates under thermal conditions translates smoothly from conventional heating into MW-assisted organic synthesis (MAOS). Reactions times are decreased from hours to minutes while good to excellent yields are maintained. MW heating should be considered for benzylation of high-value substrates using the title reagent.