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The design of organometallic catalysts is crucial in the development of catalytic reactions. Herein, we describe a heterometallic [Os-Cu] complex with the characteristics of bimetallics, metallaaromatics, and pincer complexes. This complex serves as a highly effective catalyst for selective amino- and oxyselenation of unactivated alkenes. More than 80 examples including challenging substrates of unsymmetric aliphatic alkenes and amine-based nucleophiles in such reactions are provided. These reactions produce 1,2-difunctionalized products with good yields and high levels of chemo-, regio-, and stereoselectivity. Our studies revealed the following: (i) The usually inert osmium center activates the N - or O -centered nucleophiles. (ii) The copper-osmium bonding and its cooperative effects play essential roles in control the selectivity by bringing the reaction components into close proximity. (iii) The metallaaromatic moiety helps to stabilize the intermediate. These findings provide a versatile platform for catalyst design based on metal-metallaaromatic cooperative effects that have not been attained previously with bimetallic complexes.

This article describes the full details of our synthetic efforts toward the enantioselective total synthesis of the complex alkaloid methoxystemofoline. The enantioselective construction of the tetracyclic core features: (1) the Keck allylation at the N -α bridgehead carbon to forge the tetrasubstituted stereocenter; (2) an olefin cross-metathesis reaction for the side-chain elongation that is amenable for the synthesis of congeners and analogues; and (3) a regioselective aldol addition reaction with methyl pyruvate that ensured the subsequent regioselective cyclization reaction to construct the fourth ring. Overman's method was employed to install the 5-(alkoxyalky1idene)-3-methyl-tetronate moiety. In the last step, a nonstereoselective reaction resulted in the formation of both the proposed structure of methoxystemofoline and its E -stereoisomer, the natural product (revised structure), in a 1:1 ratio. We suggest to rename the natural product as isomethoxystemofoline, and report for the first time the complete 1 H NMR data for this natural product.

A biocompatible Y(III)-based metal-organic framework [Y 4 (TATB) 2 ]·(DMF) 3.5 ·(H 2 O) (ZJU-16, H 3 TATB= 4,4',4''-(1,3,5-triazine-2,4,6-triyl) tribenzoic acid) was synthesized, and it was adopted to load Mn 2+ for chemodynamic therapy. Meanwhile, ibuprofen sodium (IBUNa), an anti-inflammatory drug, was introduced to increase the amount of Mn 2+ (about 5.66 wt %) due to the low loading capacity of Mn 2+ . Mn&IBUNa@ZJU-16 which was loaded by Mn 2+ and IBUNa exhibited significant effects of chemodynamic therapy and excellent inhibition of the 4T1 tumor cell growth, implying its long-term prospects in chemodynamic therapy and its possibility in bimodal cancer therapy.

Near-IR-emitting and/or efficiently photodynamic water-soluble Ru(II) complexes that hold great application potentials as photodynamic therapy and/or photodetection agents for cancers have been poorly explored. In this paper, the solvatochromism, calf thymus DNA binding, and singlet oxygen generation properties of a known ruthenium(II) complex of visible-emitting [Ru(bpy) 2 (dtdpq)](ClO 4 ) 2 ( Ru1 ) and a new homoleptic complex of near-IR-emitting [Ru(dtdpq) 3 ](ClO 4 ) 2 ( Ru2 ) (bpy = 2,2'-bipyridine, dtdpq = 2,3-bis(thiophen-2-yl)pyrazino[2,3- f ][1,10]phenanothroline) in water are reported. Moreover, DNA photocleavage, singlet oxygen generation in HeLa cells, cellular uptake/localization, and in vitro photodynamic therapy for cancer cells of water-soluble Ru1 are described in detail. The results show that Ru1 acted as potent photodynamic cancer therapy and mitochondrial imaging agents. Ru2 exhibited very strong solvatochromism from a visible emission maximum at 588 nm in CH 2 Cl 2 to the near-IR region at 700 nm in water and singlet oxygen generation yield in water (23%) and DNA binding properties (intercalative DNA binding constant on the order of 10 6 M -1 ) comparable to those of Ru1 , which should make Ru2 attractive for the aforementioned applications of Ru1 if the water solubility of Ru2 can be improved enough for the studies above.

A novel and environmentally attractive C(sp 3 )-H azidation of 2-oxindoles involving the formation of a C-N bond was developed. This methodology achieved for the first time 3-azido-2-oxindole construction under metal-free conditions at room temperature via a radical strategy. PhI(OAc) 2 was used as the oxidant and Et 3 N was used as the additive in this transformation. Furthermore, the mechanistic study indicated that this azidation involved a radical process.

Six new highly oxygenated grayanane diterpenoids, neopierisoids G-L, 1-6, together with 10 known related compounds, 7-16, were identified from the flowers of the poisonous plant Pieris japonica. The structures were elucidated on the basis of comprehensive NMR spectroscopy and mass analysis. The relative configurations of 1-6 were elucidated by analysis of ROESY spectra and comparison of NMR data with the analogues. The absolute configurations of 1-6 were established by the X-ray diffraction analysis of 1 and comparison of the CD spectra of 1-6. Compared with the skeleton of the normal grayanane diterpenoids, compounds 1-6 shared an unusual seco A ring moiety. The antifeedant activities of compounds 1-16 against Pieris brassicae were evaluated by using a dual-choice bioassay, and compounds 1-10 with a normal grayanane skeleton showed potent antifeedant activity against P. brassicae. The structure-activity relationships of antifeedant activities of 1-16 against P. brassicae are discussed.

Two new chlorinated multiacylated 3,4-seco-grayanane diterpenoids, neopierisoids A and B (1 and 2), were isolated from flowers of the poisonous plant Pieris japonica and were identified from spectroscopic analysis and X-ray diffraction data. Both compounds showed obvious antifeedant activity against Pieris brassicae with an EC50 of 10.07 μg/cm(2) for 1 and 5.33 μg/cm(2) for 2, indications of toxic properties. Chlorinated 3,4-seco-grayanane diterpenoids in P. japonica may play a defensive role against herbivores.

Due to the widespread occurrence in the environment and potential risk toward organisms of fluoroquinolones (FQs), it is of importance to develop high efficient methods for assessing their occurrence and environmental risk. A monoclonal antibody (Mab) with broad cross-reactivity to FQs was produced by immunizing BALB/c mice with a synthesized immunogen prepared by conjugating ciprofloxacin with bovine serum albumin. This developed Mab (C2F3C2) showed broad and high cross-reactivity (40.3-116%) to 12 out of the 13 studied FQs. Using this Mab and norfloxacin conjugated with carrier protein ovalbumin as coating antigen, a time-resolved fluoroimmunoassay (TRFIA) method was developed for determining the total concentration of at least 12 FQs in environmental waters. The respective detection limit (LOD) and IC(50) calculated from the standard curve were 0.053 μg/L and 1.83 μg/L for enrofloxacin (ENR). The LODs of the other FQs, estimated based on the corresponding cross-reactivity and the LOD of ENR, were in the range of 0.051-0.10 μg/L. The developed TRFIA method showed good tolerance to various interfering substances present in environmental matrix at relevant levels, such as humic acids (0-10 mg/L DOC), water hardness (0-2% Ca(2+) and Mg(2+), w/v), and heavy metals (0-1 mg/L). The spiked recoveries estimated by spiking 0.5, 1, and 2 μg/L of five representative FQs into various water samples including paddy water, tap water, pond water, and river water were in the range of 63-120%. The measured total FQ concentration by TRFIA agreed well with that of liquid chromatography-tandem mass spectrometry and was applied to directly evaluate the occurrence and environmental risk of FQs in the surface water of a case area. TRFIA showed high efficiency and great potential in environmental risk assessment as it measures directly the total concentration of a class of pollutants.

A new heteroleptic ruthenium(II) complex of [Ru(Hipdpa)(Hdcbpy)(NCS)(2)](-).0.5H(+).0.5[N(C(4)H(9))(4)](+) Ru(Hipdpa) {where Hdcbpy = monodeprotonated 4,4'-dicarboxy-2,2'-bipyridine and Hipdpa = 4-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-N,N-diphenylaniline} was synthesized and characterized by elementary analysis, standard spectroscopy techniques, and cyclic voltammetry. The ground- and excited-state acid-base properties of Ru(Hipdpa) were studied by means of UV-vis absorption spectrophotometric and spectrofluorimetric titrations in 4:1(v/v) Britton-Robinson/dimethylformamide buffer solution. The four-step separate protonation/deprotonation processes were found in the ground states, and one of which taking place near the physiological pH range. The two observable excited-state protonation/deprotonation processes were found for the Ru(Hipdpa), constituting pH-induced "off-on-off" emission switches. The performance of the complexes as photosensitizers in nanocrystalline TiO(2)-based liquid solar cells containing an electrolyte solution (0.05 M I(2), 0.5 M LiI, and 0.5 M 4-tert-butylpyridine in 50% acetonitrile and 50% propylene carbonate) was investigated and found to achieve a much improved device performance (a short-circuit photocurrent density of 18.7 mA cm(-2), an open-circuit voltage of 630 mV, and an overall conversion efficiency of 6.85%) compared to a triphenylamine-free parent complex [Ru(Hpip)(Hdcbpy)(NCS)(2)](-).[N(C(4)H(9))(4)](+)-based device {Hpip = 2-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline} and a comparable performance to that of cis-bis(isothiocyanato)bis(2,2'-bipyridine-4,4'-dicarboxylic acid)ruthenium(II) (N3) under identical experimental conditions. A density functional theory calculation of the molecular structures and electronic properties of the complexes was also carried out in an effort to understand their effectiveness in TiO(2)-based solar cells.

A surfactant ion-pair complex, [Ru(bpy)(2)L][Eu(NTA)(4)](2) (in which L = 1-docosyl-2-(2- pyridyl)benzimidazole, bpy = 2,2'-bipyridine, and NTA = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedionato) has been synthesized. The surface pressure-area isotherm measurements show that the complex forms a stable Langmuir film at the air-water interface without adding any electrolytes into the subphase. The monolayers formed at the surface pressures of 5 mN m(-1) and 20 mN m(-1), have been successfully transferred onto glass and quartz substrates with the transfer ratios close to unity. The Langmuir-Blodgett films were studied by UV-visible, infrared, and emission spectroscopies, atomic force microscopy, and cyclic voltammetry. The optical, redox, and morphology properties of the LB films were found to be significantly affected by the target surface pressures used for the film depositions.

A novel ruthenium(II) complex of [Ru(bpy)2(Hbopip)](ClO4)2 (in which bpy=2,2'-bipyridine, Hbopip=2-(4-benzoxazolyl)phenylimidazo[4,5-f][1,10]phenanthroline) was synthesized and characterized. The spectrophotometric pH titrations of the complex showed that it acted as a pH-induced luminescence "off-on-off" switch: a luminescence off-on switch with a luminescence enhancement factor of IpH=3.0/IpH=1.0=20 occurring over a narrow pH range of 1.00-3.00 plus a luminescence on-off switch with a luminescence enhancement factor of 3 over a pH range of 3.20-9.40. The excited-state ionization constant of the complex derived, pKa1*=3.06, is 1.36 pKa units greater than the ground-state pKa1=1.70, and pKa2*=5.01 and pKa3*=8.22 are comparable to the ground-state pKa2=5.23 and pKa3=8.22, respectively. The complex avidly bound to calf thymus DNA with a large binding constant of (1.2+/-0.3)x10(7) M-1 in buffered 50 mM NaCl, as evidenced by UV-vis and luminescence titrations, steady-state emission quenching by [Fe(CN)6]4-, DNA competitive binding with ethidium bromide, viscosity measurements, and DNA melting experiments.