The novel weakly coordinating lipophilic anion tetrakis­[3,5-bis­(pentafluorosulfanyl)­phenyl]­borate ([S-BArF 4]−) was prepared by reaction of an aryl Grignard reagent from transmetalation with boron­(III) chloride. In other routes established for the synthesis of the trifluoromethyl analogue ([BArF 4]− with ArF = 3,5-(F3C)­C6H3), the SF5 substitution resulted in a distinctly different reactivity. Na­[S-BArF 4] as a solid is stable up to >250 °C according to thermogravimetric analysis. Single-crystal X-ray analysis of the novel cationic Ni­(II) complex [Ni­(allyl)­(mesitylene)]+[S-BArF 4]− shows a tetrahedral arrangement of the aryl units at the boron center. This complex is a catalyst precursor for butadiene polymerization in heptane with high activity and 1,4-cis selectivity (≥93%). In comparison to its [BArF 4]− analogue, the polymerization activity is 2-fold higher. Electrochemical and DFT studies further underline the weakly coordinating nature of [S-BArF 4]−.

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Studies of the relative yields of CzH4 and C2H6 produced in the oxidation of propionaldehyde at 440°C in the presence and absence of Hn or D2 have enabled the velocity constant ratios ka/k14

Carbon nanodots (CNDs) synthesized from citric acid and formyl derivatives, that is, formamide, urea, or N‐methylformamide, stand out through their broad‐range visible‐light absorbance and extraordinary photostability. Despite their potential, their use has thus far been limited to imaging research. This work has now investigated the link between CNDs’ photochemical properties and their chemical structure. Electron‐rich, yellow carbon nanodots (yCNDs) are obtained with in situ addition of NaOH during the synthesis, whereas otherwise electron‐poor, red carbon nanodots (rCNDs) are obtained. These properties originate from the reduced and oxidized dimer of citrazinic acid within the matrix of yCNDs and rCNDs, respectively. Remarkably, yCNDs deposited on TiO2 give a 30% higher photocurrent density of 0.7 mA cm−2 at +0.3 V versus Ag/AgCl under Xe‐lamp irradiation (450 nm long‐pass filter, 100 mW cm−2) than rCNDs. The difference in overall photoelectric performance is due to fundamentally different charge‐transfer mechanisms. These depend on either the electron‐accepting or the electron‐donating nature of the CNDs, as is evident from photoelectrochemical tests with TiO2 and NiO and time‐resolved spectroscopic measurements.

The maximum rate of oxidation of propionaldehyde in aged boric-acid-coated vessels at 440°C has orders of 1 *5 and 0.2 with respect to aldehyde and oxygen respectively. The rate is independent of vessel diameter and is accelerated by addition of inert gas. The main kinetic features can be accounted for by a mechanism in which the rate-determining steps are :The autocatalytic nature of the reaction is attributed to reaction (7), which also accounts for the accelerating effect of inert gas. Solution of the simultaneous differential equations for -dd[C2H5CHO]/dt and d[H202]/dt gives the value of k, = 0.076ZO-020 1. mole-l sec-I, and the values of k 4 / q = 39&5 (1. mole-, sec-')+.Using ks = 1.8 x lo9 gives k4 = 1.85 x lo6 1. mole-I sec-I at 440°C.