Enantioselective formal total synthesis of dihydrospirotryprostatin B.

Spirotryprostatins are representative members of medicinally interesting bioactive molecules of the spirooxindole natural products. In this communication, we present a novel enantioselective total synthesis of the spirooxindole alkaloid dihydrospirotryprostatin B. The synthesis takes advantage of copper-catalyzed tandem reaction of o-iodoanilide chiral sulfinamide derivatives with alkynone to rapidly construct the key quaternary carbon stereocenter of the natural product dihydrospirotryprostatin B.

Merging of the photocatalyst decatungstate and naphthalene diimide in a hybrid structure for the oxidative coupling of amines.

Designing and developing novel hybrid materials for the effective photoconversion of organic substrates is of great importance. Crystalline hybrid heterostructures, as an attractive class of material, are composed of semiconducting organic and inorganic components with fast-responsive charge-separated properties and thus they are promising photocatalysts. Naphthalene diimides (NDIs) and decatungstate (W10O324-) are two versatile semiconductor components that have been utilized as building blocks for the construction of functional materials for various applications. In this context, we demonstrated that the combination of an electron-deficient NDI derivative with W10O324- resulted in an organic-inorganic hybrid compound, namely Zn2(DPNDI)(W10O32)(DMA)6 (DPNDI = N,N'-di-(4-pyridyl)-1,4,5,8-naphthalene diimide) (1). Because of consecutive photo-induced electron transfer processes among the components, this hybrid compound exhibits fast-responsive reversible photochromic properties, and it efficiently photocatalytically oxidizes amines to imines under mild conditions with high yields and an excellent substrate application range.

Correction: A photochromic zinc-based coordination polymer for a Li-ion battery anode with high capacity and stable cycling stability.

Correction for 'A photochromic zinc-based coordination polymer for a Li-ion battery anode with high capacity and stable cycling stability' by Shu-Biao Xia et al., Dalton Trans., 2018, 47, 13222-13228, DOI: 10.1039/C8DT02930J.

Correction: Naphthalimide-containing coordination polymer with mechanoresponsive luminescence and excellent metal ion sensing properties.

Correction for 'Naphthalimide-containing coordination polymer with mechanoresponsive luminescence and excellent metal ion sensing properties' by Jian-Jun Liu et al., Dalton Trans., 2020, 49, 3174-3180, DOI: 10.1039/C9DT04928B.

Naphthalimide-containing coordination polymer with mechanoresponsive luminescence and excellent metal ion sensing properties.

Mechanoresponsive luminescent materials coupled with other functionalities are of particular interest due to their multiple external stimuli responsive properties. In this paper, a new sensitive mechanoresponsive luminescent coordination polymer, [Cd(INI)(DMF)2·DMF] (1) (H2INI = N-(5-isophthalic acid)-1,8-naphthalimide), has been successfully designed and synthesized. Complex 1 exhibits interesting mechanoresponsive and grinding-enhanced luminescence properties, and its luminescence colour changed from weak blue-green to bright blue upon grinding owing to the external pressure-induced destruction of ππ stacked arrangements in local defective areas. Moreover, the luminescence properties and uncoordinated carbonyl groups of well-ground g-1 endow it with excellent sensing ability for Cr3+ ions. This work will provide a new perspective to rationally design multifunctional coordination polymers that can serve as practical multi-responsive sensors to pressure and chemicals.

A fourfold interpenetrating cadmium(II) metal-organic framework based on 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine with reversible photochromic properties.

2,4,6-Tris(pyridin-4-yl)-1,3,5-triazine (tpt), as an organic molecule with an electron-deficient nature, has attracted considerable interest because of its photoinduced electron transfer from neutral organic molecules to form stable anionic radicals. This makes it an excellent candidate as an organic linker in the construction of photochromic complexes. Such a photochromic three-dimensional (3D) metal-organic framework (MOF) has been prepared using this ligand. Crystallization of tpt with Cd(NO3)2·4H2O in an N,N-dimethylacetamide-methanol mixed-solvent system under solvothermal conditions afforded the 3D MOF poly[[bis(nitrato-κ2O,O')cadmium(II)]-µ3-2,4,6-tris(pyridin-4-yl)-1,3,5-triazine-κ3N2:N4:N6], [Cd(NO3)2(C18H12N6)]n, which was characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis and single-crystal X-ray diffraction. The X-ray diffraction crystal structure analysis reveals that the asymmetric unit contains one independent CdII cation, one tpt ligand and two coordinated NO3- anions. The CdII cations are connected by tpt ligands to generate a 3D framework. The single framework leaves voids that are filled by mutual interpenetration of three independent equivalent frameworks in a fourfold interpenetrating architecture. The compound shows a good thermal stability and exhibits a reversible photochromic behaviour, which may originate from the photoinduced electron-transfer generation of radicals in the tpt ligand.

A photochromic zinc-based coordination polymer for a Li-ion battery anode with high capacity and stable cycling stability.

Rechargeable Li-ion batteries (LIBs) are currently the dominant power source for electric vehicles and portable electronic devices, and for small-scale stationary energy storage. However, one bottleneck of the anode materials for LIBs is the poor cycling performance caused by the fact that the anodes cannot maintain their integrity over several charge-discharge cycles. In this article, a zinc-based two-dimensional coordination polymer [Zn(bcbpy)0.5(PTA)(H2O)] (Zn-BCP) has been synthesized (H2bcbpy·2Cl = 1,1'-bis(3-carboxylatobenzyl)-(4,4'-bipyridinium) dichloride, PTA = terephthalic acid), which was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy and thermogravimetric analysis. Because of the presence of electron-deficient bipyridinium moieties, Zn-BCP can easily undergo photoinduced electron transfer and eye-detectable photochromic behavior. Moreover, its luminescence can be switched by UV-Vis light irradiation. When Zn-BCP acts as an anode material for lithium ion batteries, it can deliver a high reversible capacity of 386.2 mA h g-1 at 100 mA g-1 after 100 cycles and a high capacity retention of 93.1% after 1000 cycles at a high rate of 200 mA g-1, which is supposed to be due to the flexible structure characteristic of the proposed anode. The high capacity may be mainly ascribed to rich insertion sites arising from the aromatic ligands and all of the aromatic ligands are taking part in lithium storage.

Anion-Controlled Architecture and Photochromism of Naphthalene Diimide-Based Coordination Polymers.

Three new cadmium coordination polymers, namely [Cd(NO3)2(DPNDI)(CH3OH)]·CH3OH (1), [Cd(SCN)2(DPNDI)] (2), and [Cd(DPNDI)2(DMF)2]·2ClO4 (3) (DPNDI = N,N-di(4-pyridyl)-1,4,5,8-naphthalene diimide, DMF = N,N-dimethylformamide) have been synthesized by reactions of DPNDI with Cd(NO3)2, Cd(SCN)2, and Cd(ClO4)2, respectively. Compound 1 is a one-dimensional coordination polymer with strong lone pair-π interactions between the coordinated NO3- anions and the imide ring of DPNDI; while 2 is a two-dimensional network with a (4, 4) net topology. In the case of 3, due to the presence of uncoordinated perchlorate counter ions, it exhibits a non-interpenetrated square-grid coordination polymer containing one-dimensional rhomboid channels. The structural diversity in these compounds is attributed to different coordination abilities and geometries of counter anions. Due to the presence of electron-deficient NDI moiety, the photochromic behavior of these compounds was studied. Interestingly, only compounds 1 and 3 exhibit color changes under light irradiation. The influence of the anions on the photochromism process of the NDI-based materials has been discussed.

Synthesis, characterization, cytotoxic activities, and DNA-binding studies of ternary copper(II) complexes with new coumarin derivatives.

In this study, two novel complexes [Cu(MCVH)phen(H(2)O)].ClO(4) (1) and [Cu(MCLH)phen(H(2)O)].ClO(4) (2) (here, MCVH(2)=(7-hydroxy-4-methyl-8-coumarinyl) valine, MCLH(2)=(7-hydroxy-4-methyl-8-coumarinyl) leucine) have been synthesized and characterized by elemental analyses, molar conductance, infrared spectra (IR), (1)H-NMR and UV-Vis measurements. The interactions of them with calf thymus DNA (ct DNA) have been investigated by absorption spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and viscosity measurements. Experimental results reveal an intercalative interaction with DNA for the complexes, furthermore the binding affinity of 2 is higher than that of 1 according to the calculated binding constant values. In addition, they were evaluated for their cytotoxic activities toward human prostate cancer cell (PC3), human liver cell (L02) and human myeloid leukemia cancer cell (HL-60) by acid phosphoatase assay. Both of them showed significant cytotoxic potency.

Synthesis, crystal structure, antioxidant activity, and DNA-binding studies of a novel Ni(II) [2x2] grid complex with a rigid bistridentate Schiff base ligand.

With a bistridentate Schiff-base ligand, N',N'(3)-bis[(1E)-1-(2-pyridinyl)ethylidene)] isophthalohydrazide (H(2)L), a [2x2]G grid complex, [Ni(4)(HL)(4)](ClO(4))(4).4H(2)O.0.5 CH(3)OH (1) has been synthesized and characterized spectroscopically and crystallographically. Spectrometric titrations, ethidium bromide displacement experiments, circular dichroism spectral analysis and viscosity measurements indicate that the compound 1 strongly binds with calf-thymus DNA, presumably via intercalation mechanism. Furthermore, the antioxidant activity (superoxide and hydroxyl radical) of the ligand and its nickel(II) complex is determined by using spectrophotometer methods in vitro. Complex 1 is found to possess potent antioxidant activity and be better than standard antioxidants like mannitol.