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Based on the signal amplification elements of planar VS2/AuNPs nanocomposites and CoFe2O4 nanozyme, we herein developed an electrochemical biosensor for sensitive kanamycin (Kana) quantification. A ratiometric sensing platform was presented by incorporating VS2/AuNPs nanocomposites as a support material with excellent conductivity and high specific surface area, as well as hairpin DNA (hDNA) with complementary hybridization of biotinylated Kana-aptamer. In addition, streptavidin-functionalized CoFe2O4 nanozyme with superior peroxidase-like catalytic activity were immobilized onto the aptasensor, hence the peroxidase-like catalytic reaction could yield amplified electrochemical signals. With the presence of Kana, the aptamer-biorecognition resulted in a quantitative decrease of nanozyme accumulation and an increase of methylene blue response. Under optimal conditions, the electrochemical signal ratio of the aptasensor revealed a linear relation along with the logarithmic concentration of Kana from 1 pM to 1 μM, with the limit of detection reaching to 0.5 pM. Moreover, this aptasensor exhibited excellent precision, as well as high repeatability, hence possessing potentials in real samples and for diverse targets detection by easy replacement of the matched aptamer.

Keywords: Phosphanides / Phosphane ligands / Phosphaalkenes / Tungsten P-Functional (acylphosphane)tungsten complexes 4a-f have been prepared in good yields by the reaction of phosphinidenoid complexes 2a-d with acyl chlorides 3a,b. The reactions of acyl(chloro)phosphane complex 4a at -80°C with organolithium reagents selectively led to the formation of lithiated

Reaction of the P-bifunctional phosphane complex 2 with LDA and 12-crown-4 yielded complex 4, featuring the unprecedented combination of a P–H and P–O–Li unit, via an unknown decomposition pathway. Strong spectroscopic evidence for the transient Li/OC(O)CH3 phosphinidenoid complex 5 possessing a P–Li bond was obtained through reaction of 2 with LDA in the absence of 12-crown-4.

Synthesis of phosphinite complexes 12-14a-c, 15a and 16a was achieved via reaction of transient Li/Cl phosphinidenoid complexes 6-10, prepared from dichloro(organo)phosphane complexes [(OC)5M{RPCl2}] 1-5 (1,6: R = CPh3, 2,7: R = C5Me5, 3-5, 8-10: R = CH(SiMe3)2, 1-3, 6-8: M = W, 9: M = Mo, 10: M = Cr), with different alcohols 11a-c (a: R = allyl, b: R = methyl, c: R = isopropyl). Deprotonation of complexes 12b, 13b with MeLi or (t)BuLi in the presence of two equivalents of 12-crown-4 led to the selective formation of phosphinidenoid complexes [Li(12-crown-4)2] [(OC)5W{RP(OCH3)}] (18a R = CPh3 and 18b R = C5Me5) which were stable in solution at ambient temperature, in contrast to Li/OMe phosphinidenoid complexes without 12-crown-4. To our surprise attempts to crystallise complex 18b yielded complex 21 having a Li-O-P subunit. The reaction of complex 17c with [Ph3C]BF4 yielded the P-C coupling product 26 and, hence, the first evidence for an oxidative SET reaction. All isolated products were characterised by multinuclear NMR spectroscopy, IR, MS and single-crystal X-ray crystallography in the case of complexes 12a,b, 13b, 14a-c, 15a, 16a and 21.

Reaction of LAl(η2-Me3SiC2SiMe3) (1; L = HC[(CMe)(NDipp)]2, Dipp = 2,6-iPr2C6H3) with pyridine afforded the (1,2-dihydropyridyl)aluminum species LAl[C2(SiMe3)2CHN(C4H4)] (2), having an AlC3N five-membered ring, as a major product via insertion into one of the Al−C bonds, while hydrolysis of 1 at low temperature resulted in ring cleavage to yield the monomeric aluminum alkenyl hydroxide LAl(OH)[C(SiMe3)CH(SiMe3)] (3). The molecular structures of 2 and 3 were determined by X-ray single-crystal analysis.

A simple and efficient method for hydrotrifluoromethylation of unactivated alkenes was reported. The reaction relied on the single electron oxidation of a commercially available sodium trifluoromethanesulfinate (CFSONa, Langlois' reagent) using Mn(OAc)·2HO as the oxidant and the subsequent addition of trifluoromethyl radical to C═C double bonds. The reaction proceeded readily under mild conditions with good tolerance of a variety of functional groups in the substrates. The preliminary reaction mechanism was studied with deuteration, radical clock, and TEMPO inhibition experiments.

Keywords: Phosphanes / P ligands / Lithium / Phosphinidenoids / Tungsten / Structure elucidation P-H,P-OR-substituted phosphane complexes 3a-e have been synthesized by two methods: (1) the thermal reaction of 2Hazaphosphirene complex 1 with methanol, n-butanol, or ethylene glycol monomethyl ether (3b,c,e) or (2) the reaction of P-chlorophosphane complex 2 with appropriate sodium phenolate salts (3a,d). All the complexes 3a-e were obtained in good yields and fully characterized by NMR, IR, MS, and elemental analysis. Furthermore, the structures of 3a, 3d and 3e were confirmed unambiguously by X-ray analysis. The de-