•Selenoanthracene and CuI give cluster [Cu2I2L2]n showing visible absorption.•In situ assembly strategy constructs core-shell TiO2-[Cu2I2L2]n nanocomposites.•Polymeric shell and anthracene unit enhance photogenerated electron transfer.•TiO2-[Cu2I2L2]n is visible-light photocatalyst with high stability.1D loop chain copper(I) cluster, [Cu2I2L2]n, can be obtained based upon 9-(3-phenylselanyl-2-phenylselanylmethylpropyl)anthracene (L) and CuI. A facile in situ surface assembly strategy was designed to construct polymeric [Cu2I2L2]n on the surface of TiO2 nanoparticles. The visible-light photocatalytic property of core-shell TiO2-[Cu2I2L2]n was confirmed by effective reduction of aqueous chromium(VI), showing a clear correlation to optical absorption (Eg = 2.8 eV). The key points of this strategy include high reactivity between copper(I) and soft selenium atom, efficient charge-transfer through polymeric cluster shell, and visible-light photoactivity of copper(I) halogen clusters.Download high-res image (168KB)Download full-size image

Two novel macrocyclic polyselena[n]ferrocenophanes containing a pendent benzyl unit, 20-membered Se4N2[7,7]ferrocenophane (L1) and 10-membered Se2N[10]ferrocenophane (L2), were designed and synthesized. The reaction of L1 with two molar amounts of metal salts (M = Cu+, Cu2+, Pd2+ and Hg2+) led to six dimetallic complexes 1–6. A crystallographic study revealed that each metal center in 1–5 was tetracoordinated to two selenium atoms from different ferrocene units, one aliphatic nitrogen atom and one co-ligand. The structures of the complexes contain a two-fold axis perpendicular to the molecular plane with two pendant benzyl moieties in an anti-conformation. Macrocycle L1 gives significant electrochemical, linear and third-order nonlinear optical responses to Cu2+ and Hg2+. The DFT/B3LYP calculations of 4 demonstrated a small HOMO–LUMO energy gap and delocalization of the π-electron cloud in the frontier molecular orbitals, which led to the enhancement of molecular NLO properties after complexation. The results show that the oxidation state of the ferrocene unit is accompanied by significant differences in the corresponding absorption spectra and third-order NLO properties.

One ferrocenyl-dopamine (L1) and four ferrocenylseleno-dopamine derivatives (L2–L5) were designed and prepared with different structural parameters, such as chalcogen atoms, cycle, and semirigidity. The best in vitro anticancer activity occurred with 1,5-diselena[8]ferrocenophane L5, which inhibited cancer cell growth at the lowest micromolar concentrations. The biological studies showed that L5 arrested the cell cycle in G1 phase and induced apoptosis by activating caspase 3/9, also inhibiting endothelial cell (HUVECs) formation. It exhibited better in vivo antitumor activity in mice bearing HepG2 tumor xenograft in comparison to free dopamine. The results suggest that the excellent biological activities can be attributed to the synergetic effect of the ferrocenophane, chalcogen atom, and catechol group.

Using the hexafluoroacetylacetonato (hfac), azide anion and compartmental Schiff-base ligand H2valpn (H2valpn = 1,3-propanediylbis(2-iminomethylene-6-methoxy-phenol), three isomorphous Ni–Ln heterodinuclear complexes, [Ni(N3)(H2O)(valpn)Gd(hfac)2(H2O)]·H2O (1), [Ni(N3)(H2O)(valpn)Tb(hfac)2(H2O)]·H2O (2) and [Ni(N3)(H2O)(valpn)Dy(hfac)2(H2O)]·H2O (3), were synthesized. Structural analyses reveal that the Ni(II) and Ln(III) ions are doubly bridged by two phenoxo oxygen atoms of the valpn ligand. Magnetic susceptibility measurements show ferromagnetic couplings are operative between the Ni(II) and Ln(III) ions in 1–3. Ac susceptibility measurements under a dc-applied field of 1000 Oe disclose that the Dy derivative exhibits field-induced single-molecule magnet behavior with an effective energy barrier of 16.9 K for reversal of the magnetization.

By diffusion of methyl tert-butyl ether vapor into an acetonitrile solution containing [Ni(L)(H2O)2] (L = 1,2-bis(3-methoxy-salicylideneaminooxy)ethane) and Ln(NO3)3·6H2O, three Ni–Ln heterometallic complexes, [Ni(μ-L)(MeCN)2Ln(NO3)3] (Ln = Gd for 1, Tb for 2), and [Ni(μ-L)(MeCN)Dy(NO3)2(μ-NO3)·MeCN]n (3) were obtained. When the reaction was carried out in methanol/chloroform (2:1) containing H2L, Ni(Ac)2·4H2O and Ln(NO3)3·6H2O with diffusion of diethyl ether vapor, two Ni–Ln heterometallic complexes [Ni(μ-L)(CH3OH)(μ-NO3)Ln(NO3)2] (Ln = Tb for 4, and Dy for 5) were synthesized. The X-ray analyses demonstrated that complexes 1, 2, 4 and 5 display 3d–4f heterodinuclear structures, and that the NiII and LnIII ions are bridged by diphenolato atoms for 1 and 2, and by a syn–syn nitrate group and diphenolato atoms for 4 and 5. Compound 3 is made of a rare anti–anti nitrate- and phenolate-bridged Ni–Dy heterometallic chain. All complexes exhibit a net ferromagnetic interaction between the NiII and LnIII ions. Alternating current susceptibility measurements demonstrated that compound 3 behaved as a single-molecule magnet with an effective energy barrier of 15.8 K under a zero direct current field, however, 5 only displayed slow magnetic relaxation under a 2000 Oe direct current field.

•Two mixed donor Se/O multichannel sensors were obtained.•Only Cu2 + ions switch-on fluorescence intensity.•Cu2 + induces the oxidation of ferrocene unit and then form stable Cu+ complex.Two mixed-donor molecules containing ferrocene and anthracene moiety, 1 and 2, have been designed and synthesized as potential multichannel probes for transition metal cations. They displayed switch-on fluorescence intensity only with Cu2 + among the metal ions examined. Electrochemistry and UV–vis spectra studies showed that Cu2 + induces the oxidation of ferrocene unit and then forms stable Cu+ complex.Two mixed-donor multichannel molecular probes were synthesized. They displayed switch-on fluorescence intensity with Cu2+, due to Cu2+ oxidation of ferrocene unit and the formation of stable Cu+ complex.

Two novel macrocyclic polyselena[n]ferrocenophanes containing a pendent benzyl unit, 20-membered Se4N2[7,7]ferrocenophane (L1) and 10-membered Se2N[10]ferrocenophane (L2), were designed and synthesized. The reaction of L1 with two molar amounts of metal salts (M = Cu+, Cu2+, Pd2+ and Hg2+) led to six dimetallic complexes 1–6. A crystallographic study revealed that each metal center in 1–5 was tetracoordinated to two selenium atoms from different ferrocene units, one aliphatic nitrogen atom and one co-ligand. The structures of the complexes contain a two-fold axis perpendicular to the molecular plane with two pendant benzyl moieties in an anti-conformation. Macrocycle L1 gives significant electrochemical, linear and third-order nonlinear optical responses to Cu2+ and Hg2+. The DFT/B3LYP calculations of 4 demonstrated a small HOMO–LUMO energy gap and delocalization of the π-electron cloud in the frontier molecular orbitals, which led to the enhancement of molecular NLO properties after complexation. The results show that the oxidation state of the ferrocene unit is accompanied by significant differences in the corresponding absorption spectra and third-order NLO properties.

Six copper(I) halide clusters based upon ferrocenyltelluroethers or ferrocenylselenoethers, 1–6, have been synthesized and structurally characterized by an X-ray crystallographic study. These structures include a discrete step-cubane Cu4I4 cluster, a 1D chain with rhomboid Cu2X2 clusters, a 1D chain with cubane Cu4I4 clusters and a 2D network with Cu2I2 clusters. 1–3 are the first structurally characterized example of copper(I) clusters with telluroethers. Their different nuclearities and geometries can be attributed to the different donor atoms and chain flexibility in the ligands. The catalytic activities of six clusters were then investigated in the Ullmann C–N cross-coupling reaction and 2 displayed the best performance with a target product N-(4-phenyl)imidazole in 91.3% yield. From the viewpoint of structure, the specific steric acceptance around Cu(I) in 2 may allow imidazole and iodobenzene to stepwise coordinate with the copper center and give the target product effectively.