White-Light Emission and Circularly Polarized Luminescence from a Chiral Copper(I) Coordination Polymer through Symmetry-Breaking Crystallization.

Achieving white-light emission, especially white circularly polarized luminescence (CPL) from a single-phase material is challenging. Herein, a pair of chiral CuI coordination polymers (1-M and 1-P) have been prepared by the asymmetrical assembly of achiral ligands and Cu2 I2 clusters. The compounds display dual emission bands and can be used as single-phase white-light phosphors, achieving a "warm"-white-light-emitting diode with an ultra-high color rendering index (CRI) of 93.4 and an appropriate correlated color temperature (CCT) of 3632 K. Meanwhile, corresponding CPL signals with maximum dissymmetry factor |glum |=8×10-3 have been observed. Hence, intrinsic white-light emission and CPL have been realized simultaneously in coordination polymers for the first time. This work gains insight into the nature of chiral assembly from achiral units and offers a prospect for the development of single-phase white-CPL materials.

Magnetic Properties of 3D Heptanuclear Lanthanide Frameworks Supported by Mixed Ligands.

Two 3D lanthanide frameworks, [Ln7(DPA)5(NA)3(µ3-OH)8(H2O)3]·2.5H2O [H2DPA = diphenic acid; HNA = nicotinic acid; Ln = Gd (1), Dy (2)], were synthesized and structurally characterized. They were rarely seen examples of 3D frameworks constructed from heptanuclear trigonal-antiprismatic lanthanide clusters with mixed H2DPA and HNA ligands. Both 1 and 2 show typical antiferromagnetic interactions. Additionally, complex 1 possesses a large magnetocaloric effect of 34.15 J kg(-1) K(-1).

Construction of two microporous metal-organic frameworks with flu and pyr topologies based on Zn4(µ3-OH)2(CO2)6 and Zn6(µ6-O)(CO2)6 secondary building units.

By employment of a tripodal phosphoric carboxylate ligand, tris(4-carboxylphenyl)phosphine oxide (H3TPO), two novel porous metal-organic frameworks, namely, [Zn4(µ3-OH)2(TPO)2(H2O)2] (1) and [Zn6(µ6-O)(TPO)2](NO3)4·3H2O (2), have been synthesized by solvothermal methods. Complexes 1 and 2 exhibit three-dimensional microporous frameworks with flu and pyr topologies and possess rare butterfly-shaped Zn4(µ3-OH)2(CO2)6 and octahedral Zn6(µ6-O)(CO2)6 secondary building units, respectively. Large cavities and one-dimensional channels are observed in these two frameworks. Gas-sorption measurements indicate that complex 2 has a good H2 uptake capacity of 171.9 cm(3) g(-1) (1.53 wt %) at 77 K and 1.08 bar, and its ideal adsorbed solution theory calculation predicts highly selective adsorption of CO2 over N2 and CH4. Furthermore, complexes 1 and 2 exhibit excellent blue emission at room temperature.

Chitosan combined with molecular beacon for mir-155 detection and imaging in lung cancer.

Lung cancer is the major cause of cancer-related deaths worldwide, thus developing effective methods for its early diagnosis is urgently needed. In recent years, microRNAs (miRNAs, miR) have been reported to play important roles in carcinogenesis and have become potential biomarkers for cancer diagnosis and treatment. Molecular beacon (MB) technology is a universal technology to detect DNA/RNA expression in living cells. As a natural polymers, chitosan (CS) nanoparticles could be used as a carrier for safe delivery of nucleic acid. In this study, we developed a probe using nanoparticles of miR-155 MB self assembled with CS (CS-miR-155 MB) to image the expression of miR-155 in cancer cells. Hybridization assay showed that the locked nucleic acid (LAN) modified miR-155 MB could target miR-155 effectively and sensitively. The miR-155 MB self-assembly with CS nanoparticles formed stable complexes at the proper weight ratio. The CS nanoparticles showed higher fluorescence intensity and transfection efficiency than the lipid-based formulation transfection agent by confocal microscopy and flow cytometry analysis. The CS-MB complexes were found to be easily synthesized and exhibited strong enzymatic stability, efficient cellular uptake, high target selectivity and biocompatibility. The CS-MB complexes can also be applied in other cancers just by simply changing for a targeted miRNA highly expressed in those cancer cells. Therefore, it is a promising vehicle used for detecting miRNA expression in living cells.

1D Cu(I)-based chiral organic-inorganic hybrid material with second harmonic generation and circular polarized luminescence.

In recent years, organic-inorganic hybrid materials have demonstrated exceptional performance in nonlinear optics, attracting widespread attention. However, there are relatively few examples of coordination compounds synthesized with Cu as the metal center that exhibit excellent nonlinear optical properties. In this study, we successfully synthesized a pair of enantiomers named R/S-Cu2I2 by reacting chiral ligands with CuI. The crystal structure reveals a one-dimensional copper-iodide chain structure built by Cu2I2 clusters, and its ordered arrangement in space provides not only a strong second harmonic generation (SHG) signal (1.24 × KDP) but also a large birefringence (0.15@1064 nm). Under excitation at 395 nm, the crystals exhibit red fluorescence peaked at 675 nm. The CD spectra of R/S-Cu2I2 show a distinct mirror-symmetric Cotton effect, and their CPL signals are corresponding and opposite in the emission range, with a maximum glum of approximately ±2.5 × 10-3. Theoretical calculations using density functional theory were also carried out to enhance our understanding of the correlation between their structures and optical properties.

Photophysical studies of europium coordination polymers based on a tetracarboxylate ligand.

Reaction of europium sulfate octahydrate with p-terphenyl-3,3″,5,5″-tetracarboxylic acid (H4ptptc) in a mixed solvent system has afforded three new coordination polymers formulated as {[Eu(ptptc)0.75(H2O)2]·0.5DMF·1.5H2O}n (1), {[Me2H2N]2 [Eu2(ptptc)2(H2O)(DMF)]·1.5DMF·7H2O}n (2), and {[Eu(Hptptc)(H2O)4]·0.5DMF·H2O}n (3). Complex 1 exhibits a three-dimensional (3D) metal-organic framework based on {Eu2(µ2-COO)2(COO)4}n chains, complex 2 shows a 3D metal-organic framework constructed by [Eu2(µ2-COO)2(COO)6](2-) dimetallic subunits, and complex 3 features a 2D layer architecture assembling to 3D framework through π···π interactions. All complexes exhibit the characteristic red luminescence of Eu(III) ion. The triplet state of ligand H4ptptc matches well with the emission level of Eu(III) ion, which allows the preparation of new optical materials with enhanced luminescence properties. The luminescence properties of these complexes are further studied in terms of their emission quantum yields, emission lifetimes, and the radiative/nonradiative rates.

Chlorine-induced assembly of a cationic coordination cage with a µ5-carbonato-bridged Mn(II)24 core.

Chlorine caged in! The chlorine-induced assembly of six shuttlecock-like tetranuclear Mn(II) building blocks generated in situ based on p-tert-butylthiacalix[4]arene and facial anions gave rise to a novel truncated distorted octahedral cationic coordination cage with a µ(5)-carbonato-bridged Mn(II)(24) core.

Visible and NIR photoluminescence properties of a series of novel lanthanide-organic coordination polymers based on hydroxyquinoline-carboxylate ligands.

A series of novel two-dimensional (2D) lanthanide coordination polymers with 4-hydroxyquinoline-2-carboxylate (H(2)hqc) ligands, [Ln(Hhqc)(3)(H(2)O)](n)·3nH(2)O (Ln = Eu (1), Tb (2), Sm (3), Nd (4), and Gd (5)) and [Ln(Hhqc)(ox)(H(2)O)(2)](n) (Ln = Eu (6), Tb (7), Sm (8), Tm (9), Dy (10), Nd (11), Yb (12), and Gd (13); H(2)ox = oxalic acid), have been synthesized under hydrothermal conditions. Complexes 1-5 are isomorphous, which can be described as a two-dimensional (2D) hxl/Shubnikov network based on Ln(2)(CO(2))(4) paddle-wheel units, and the isomorphous complexes 6-13 feature a 2D decker layer architecture constructed by Ln-ox infinite chains cross-linked alternatively by bridging Hhqc(-) ligands. The room-temperature photoluminescence spectra of complexes Eu(III) (1 and 6), Tb(III) (2 and 7), and Sm(III) (3 and 8) exhibit strong characteristic emissions in the visible region, whereas Nd(III) (4 and 11) and Yb(III) (12) complexes display NIR luminescence upon irradiation at the ligand band. Moreover, the triplet state of H(2)hqc matches well with the emission level of Eu(III), Tb(III), and Sm(III) ions, which allows the preparation of new optical materials with enhanced luminescence properties.

Self-assembly of discrete M6L8 coordination cages based on a conformationally flexible tripodal phosphoric triamide ligand.

Reactions of a tripodal ligand, N,N',N″-tris(3-pyridinyl)phosphoric triamide (TPPA), and a series of transition-metal ions result in the assembly of five discrete M(6)L(8) coordination cages [M(6)(TPPA)(8)(H(2)O)(12)](ClO(4))(12)·57H(2)O [M = Ni(2+) (1), Co(2+) (2), Zn(2+) (3), Cd(2+) (4)] and [Pd(6)(TPPA)(8)]Cl(12)·22H(2)O (5). X-ray structural analyses reveal that the cages have large internal cavities and flexible windows. The flexible ligand TPPA adopts the syn conformation in cages 1-4, but it transforms to the anti conformation in cage 5. Because of the conformational transformation, the sizes of the windows and the volume of the internal cavity of cage 5 are increased. (1)H NMR and electrospray mass spectrometric studies show that cage 5 maintains its structural integrity in solution. Additionally, compounds 3 and 4 exhibit strong blue fluorescent emissions, which are 1 order of magnitude higher than that of the free ligand.

Cobalt-lanthanide coordination polymers constructed with metalloligands: a ferromagnetic coupled quasi-1D Dy3+ chain showing slow relaxation.

Four types of cobalt-lanthanide heterometallic compounds based on metalloligand Co(2,5-pydc)(3) (3-) (2,5-H(2)pydc=pyridine-2,5-dicarboxylate acid), [Ln(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n) 2n H(2)O (1) (Ln=Tb, Dy for 1 a, 1 b respectively), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n)3n H(2)O (2), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(9)](n)4n H(2)O (3), and [LaCo(2,5-pydc)(3)(H(2)O)(2)](n)2n H(2)O (4) have been synthesized. Compound 1 has a layer structure with well-isolated carboxylate-bridged Ln(3+) chains, compound 2 is a three-dimensional (3D) porous network with Tb(3+) chains that are also well isolated and carboxylate bridged, 3 is a layer structure based on dinuclear units, and 4 is a 3D network with boron nitride (BN) topology. DC magnetic studies reveal ferromagnetic coupling in all the carboxylate-bridged Ln(3+) chains in 1 a, 1 b, and 2. Compared to the silence of the out-of-phase ac susceptibility of 2, above 1.9 K the magnetic relaxation behavior of both 1 a and 1 b is slow like that of a single-chain magnet.

Identification and imaging of miR-155 in the early screening of lung cancer by targeted delivery of octreotide-conjugated chitosan-molecular beacon nanoparticles.

Lung cancer is still the most common cancer globally. Early screening remains the key to improve the prognosis of patients. There is currently a lack of specific and sensitive methods for early screening of lung cancer. In recent years, studies have found that microRNA plays an important role in the occurrence and development of lung cancer and become a biological target in the early diagnosis of lung cancer. In this study, lung cancer cells, subcutaneous xenografts of lung cancer in nude mice, and Lox-Stop-lox K-ras G12D transgenic mice were used as models. The transgenic mice displayed the dynamic processes from normal lung tissue to atypical hyperplasia, adenomas, carcinoma in situ and lung adenocarcinoma. It was found that miR-155 and somatostatin receptor 2 (SSTR2) were expressed in all the disease stages of transgenic mice. Through molecular beacon (MB) technology and nanotechnology, chitosan-molecular beacon (CS-MB) nanoparticles and targeted octreotide (OCT) were conjugated and synthesized. The octreotide-conjugated chitosan-molecular beacon nanoparticles (CS-MB-OCT) can specifically bind to SSTR2 expressed by the lung cancer cells to achieve the goal of identification of lung cancer cells and imaging miR-155 in vivo and in vitro. Fluorescence imaging at different disease stages of lung cancer in Lox-Stop-lox K-ras G12D transgenic mice was performed, and could dynamically monitor the occurrence and development of lung cancer by different fluorescence intensity ranges. The current research, in turn, provides new idea, new method, and new technology for the early screening of lung cancer.

A series of novel zinc(II) entangled coordination polymers based on carboxyphenyl-terpyridine ligands.

Hydrothermal synthesis has afforded five divalent zinc coordination polymers containing 4-(4-carboxyphenyl)-2,2':6',2''-terpyridine (HL1) or its isomer 4-(4-carboxyphenyl)-2,2':4',4''-terpyridine (HL2), with or without the addition of auxiliary ligands, 1,3,5-benzenetricarboxylic acid (H3btc) and 1,4-benzenedicarboxylic acid (H2bdc). Their structures have been characterized by single crystal X-ray analyses and further characterized by infrared spectra, elemental analyses, powder X-ray diffraction, thermogravimetric analyses and photoluminescent spectra. Across this series, the π···π interactions have a dramatic impact on the self-assembly of these entanglement structures, in either case it can exert an important structure-directing role. In addition, the disposition of pyridine nitrogen atoms in ligands also plays a large role in structure direction in this system. Complex 1 is a 2D + 2D→3D inclined polycatenated coordination polymer based on the resulting array of 2D (6,3) layers constructed by 1D→2D π···π directed self-assembly. Complex 2 is assembled into a 3D framework by means of 1D + 1D→3D mutual interdigitation based on 1D→1D self-assembly driven by π···π stacking interactions. Complex 3 shows a 2D + 2D→3D interdigital network involving 2D + 2D→2D parallel interpenetrated and 2D + 2D→2D interdigital (4,4) layer motifs. Complex 4 displays a 2D + 2D→3D polythreaded framework based on a 2D (4,4) network comprised of alternating rings and rods. Complex 5 is a (3,4)-connected 3D framework with topology (4.8(2).10(3))(4.8(2)). In comparison with covalently connected entanglements, such π···π directing self-assembly of entanglements are far less explored, especially, polycatenane based on 1D chain motifs and polythread based on 2D layer motifs are rarely reported. Furthermore, the luminescent properties of complexes 1-5 at room temperature have also been studied in detail herein.

A solid AND logic stimuli-responsive material with bright nondestructive performance designed by sensitive cuprophilicity.

A stimuli-responsive material with AND logic function was realized by modulating sensitive Cu-Cu interactions, which is quite different from traditional photoinduced electron transfer (PET) strategies. The obtained material not only gets rid of fluid media, but also displays nondestructive, high intensity optical signals and environmentally friendly performances.

Unprecedented three-level hierarchical entanglement in a coordination polymer.

An unprecedented three-level hierarchical entangled system was synthesized. The basic helical ribbons of the complex were entangled into 2D layers by self-penetration based on 1D → 2D polycatenation; a pair of layers interpenetrated, and crosslinked to construct the second self-penetrated bilayers which were further polycatenated into the final 3D entangled array.

The unusual thermochromic NIR luminescence of Cu(I) clusters: tuned by Cu-Cu interactions and packing modes.

Two hexanuclear Cu(I) clusters [Cu(I)(3)(4-ptt)(3)](2)·3DMF·3H(2)O (1) and [Cu(I)(4-ptt)](6)·8DMF·7H(2)O (2) (4-Hptt = 5-(pyridin-4-yl)-1H-1,2,4-triazole-3-thiol, DMF = N,N-dimethylformamide), were synthesized and characterized. Compounds 1 and 2 with similar coordination environments are isomers, but their detailed structures are different due to the reaction temperature tuning effect. Both 1 and 2 extend from monomers to 3D supramolecules with the help of hydrogen bonding between the triazole and pyridine from the 4-ptt ligands. The Cu(6)S(6) units of 1 pack in a polydirectional array, while the Cu(6)S(6) units in 2 extend in one direction and link the planes of adjacent ligands to enhance the delocalization of π electrons. Their varied Cu-Cu interactions and individual packing modes cause differences in luminescent and thermostable behaviors. Compound 1 exhibits an unusually long wavelength at about 900 nm and a higher thermal stability; while the emission of 2 splits into two bands (high-energy and low-energy emission bands) as the temperature decreases. Therefore, the emissions of 1 originate from a (3)CC transition, and those of 2 are from a mixture of (3)CC and MLCT.

A non-interpenetrated porous metal-organic framework with high gas-uptake capacity.

A novel microporous polyhedral framework [Zn(6)(btb)(4)(4,4'-bipy)(3)(dmf)(55)(H(2)O)(32)] with high surface area has been designed and synthesized, which shows high multigas-uptake capacity via supercritical carbon dioxide (SCD) activation.

A luminescent homochiral 3D Cd(II) framework with a threefold interpenetrating uniform net 8(6).

A luminescent homochiral 3D metal-organic framework, [Cd(dtba)(bpp)](3n) () (H(2)dtba = 2,2'-dithiobisbenzoic acid, bpp = 1,3-bis(4-pyridyl)propane), with an unprecedented threefold interpenetrating uniform network (8(6)), constructed from [Cd(dtba)](n) single helices and [Cd(bpp)](n) double-stranded helices, has been synthesized via hydrothermal reaction.

An interwoven Fe3L3 trigonal metallamacrocycle from an in situ ligand hydrolysis reaction.

Through an in situ hydrolysis reaction of the bishydrazone ligand H4L1 [H4L1=(HOC6H4)CH=NNHCO(C5H3N)CONHN[double bond, length as m-dash]CH(C6H4OH)], in the presence of Fe(III) ions, an interwoven trigonal metallamacrocycle [Fe3L3(H2O)3].9H2O () [H3L=(HOC6H4)CH=NNHCO(C5H3N)CO2H] containing unusually double-layered capsule-like water hexamers was obtained and characterized by elemental analysis, FT-IR, TGA, ESI-MS and X-ray crystallography.

New lanthanide hybrid as clustered infinite nanotunnel with 3D Ln-O-Ln framework and (3,4)-connected net.

A series of new lanthanide hybrids [Ln3(mu-OH)4 (2,5-pydc)(2,5-Hpydc)3(H2O)4]n (Ln = Gd (1), Dy (2), Er (3), Eu (4), Sm (5), Yb (6), Y (7); 2,5-pydc=pyridine-2,5-dicarboxylate), as clustered lanthanide oxide ring tunnels with helical dodecahedral chains and fully 3D Ln-O-Ln connectivity, has been hydrothermally synthesized and characterized. The inorganic skeleton of the hybrid can be specified by the Schläfli symbol (6210)2 (64102) as a single 3D (3,4)-connected net. The luminescence properties have been studied, and the results showed that the Dy(III) (2) and Eu(III) (4) complexes exhibited sensitized luminescence in the visible region. Variable-temperature magnetic susceptibility measurements of 1-6 showed that the complexes 1-3 are nearly paramagnets, whereas the depopulation of the Stark levels in complexes 4-6 leads to a continuous decrease in mu(eff) when the sample is cooled from 300 to 2 K.