Six novel copper(ii) complexes of [CuCl]ClO4 (), [Cu(acac)]PF6 (), [CuCl]2(PF6)2 (), [CuCl]2(PF6)2 (), [Cu(acac)]PF6 () and [Cu(acac)]PF6 (), ( = 1-naphthyl-N,N-[bis(2-pyridyl)methyl]amine, = R/S-1-naphthyl-N,N-[bis(2-pyridyl)methyl]ethanamine, acac = diacetone) were synthesized to serve as artificial nucleases. All complexes were structurally characterized using X-ray crystallography. The crystal structures showed the presence of distorted square-planar CuLCl (, and ) and distorted tetragonal-pyramidal CuL(acac) (, and ) geometry. The interaction of these complexes with calf thymus DNA (CT-DNA) was researched by means of several spectroscopy methods, which indicated that the complexes were bound to CT-DNA by an intercalation binding mode. DNA cleavage experiments revealed that the complexes exhibited remarkable DNA cleavage activities in the presence of H2O2, and single oxygen ((1)O2) or hydroxyl radicals may serve as the major cleavage active species. In particular, the in vitro cytotoxicity of the complexes on four human cancer cell lines (HeLa, MCF-7, Bel-7404 and HepG-2) demonstrated that the six compounds had broad-spectrum anti-cancer activity with low IC50 values. The stronger cytotoxicity and DNA cleavage activity of the chiral enantiomers compared with chiral analogues verified the influence of chirality on the antitumor activity of complexes. Meanwhile, the protein binding ability was revealed by quenching of tryptophan emission with the addition of complexes using BSA as a model protein. The results indicated that the quenching mechanism of BSA by the complexes was a static process.

Four closely related mononuclear nickel(II) complexes [Ni(L)(diimine)Cl](ClO 4 ) (1-4), where L is a tridentate polypyridyl ligand of 4-methyl-N,N-bis(pyridin-2-ylmethyl)aniline and diimine is 2,2′-bipyridine (bpy, 1), 1,10-phenanthroline (phen, 2), dipyrido [3,2-d:20,30-f]quinoxaline (dpq, 3) or dipyrido[3,2-a:20,30-c]phenazine (dppz, 4), have been synthesized and characterized by using various physico-chemical techniques. All Ni centers adopt distorted octahedral geometry with N 5 Cl donor sets. From 1 to 4, the dihedral angles between benzene ring of L and the plane of the diimine exhibit gradually decline (52.5-6.8°), leading to the increasing steric encumbrance. The interactions of the complexes with CT-DNA and BSA have been explored by using absorption and emission spectral methods. These complexes display binding propensity to the CT-DNA giving a relative order: 4 (dppz) > 3 (dpq) > 2 (phen) > 1 (bpy), and the quenching mechanisms of BSA by all complexes are static procedures. In the absence of any external agents, only 1 (bpy) and 4 (dppz) exhibit apparent DNA cleavage activity, while with the addition of GSH or on the irradiation with UV-A light of 365 nm, the DNA cleavage abilities of the complexes are obviously enhanced, which vary as 1> 2 > 3 > 4 (GSH) and 4 > 3 > 2 > 1 (UV-A). In addition, the vitro  Corresponding authors. cytotoxicity of the complexes on tumor cells lines (MCF-7, HepG-2 and SGC-7901) have been examined by MTT and the morphological assessment obtained by using Hoechst 33342 staining reveals that 4 against HepG-2 induces apoptosis.

Non‐methane hydrocarbons (NMHCs) play an important role in atmospheric chemistry and the ocean is a source of NMHCs in the atmosphere. Here, we investigated the annual variations of NMHCs concentrations and fluxes (i.e., ethane, ethylene, propane, propylene, and isoprene) in the semi‐enclosed shallow waters of Jiaozhou Bay from September 2016 to August 2017. Ethylene is the most abundant NMHCs, with an annual average concentration of 487.7 ± 239.3 pmol L−1. The concentrations of other NMHCs were lower; the average concentrations for ethane, propane, propylene, and isoprene were 87.0 ± 49.0, 65.7 ± 22.9, 127.4 ± 77.8, and 60.5 ± 47.1 pmol L−1, respectively. NMHCs concentrations varied largely between seasons and higher abundance were observed in summer. The correlations between NMHCs and environmental variables such as chlorophyll a (Chl‐a), dissolved organic carbon (DOC) were ambiguous, and principal component analysis (PCA) suggested nutrients contributed significantly to total variation. These results indicated that the control of NMHCs could be more complex in dynamic and anthropogenically impacted estuarine systems, which could be a result of multiple processes involving phytoplankton release, photochemical production, riverine input, and so forth. The average annual sea‐to‐air fluxes of ethane, ethylene, propane, propylene, and isoprene were 105.9–298.3, 583.5–1,337.0, 36.7–95.2, 85.2–389.6, and 25.2–182.4 nmol m−2 d−1, respectively. Although coastal and estuarine environments only account for a minor fraction of the global ocean (0.26%–0.39%), NMHC emissions from these areas could influence regional atmospheric chemistry and may be relatively important for global budgets (ethane, 1.70%; ethylene, 1.54%; propane, 1.29%; propylene, 0.87%; isoprene, 3.17%).