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BACKGROUND: According to statistics of the Ministry of Health and Welfare in 2017, the second leading cause of death in Taiwan was lung cancer. OBJECTIVE: Routine treatment planning does not consider photoneutron dose equivalent (PNDE) of patient induced secondary radiation resulting from primary exposure of lung cancer. However, such treatment is potentially important for improving estimates of health risks. METHODS: This study used 10, 30, 50, 70, and 90 kg of polymethylmethacrylate (PMMA) phantoms as patient to measure PNDE varying anatomical area during lung cancer of intensity modulated radiotherapy (IMRT) treatment. Paired thermoluminescent dosimeters (TLD-600 and 700) were calibrated using university reactor neutrons. TLDs were inserted into phantom which was closely corresponded of the represented tissues or organs. RESULTS: Neutron doses (ND) of organ or tissue (N⁢DT) were determined in these phantoms using paired TLDs approach. The risks of incurring fatal secondary malignancies, maximum statistical and total errors were estimated. Evaluated PNDE ranged from 0.80 ± 0.12 to 0.56 ± 0.08 mSv/Gy for these phantoms. CONCLUSION: The estimated N⁢DT decreased with increasing distance that is from the central axis. Evaluated PNDE and N⁢D𝑠𝑘𝑖𝑛 for these phantoms were discussed. This investigation also identified secondary risks associated with PNDE relating to radiation protection.

We designed two near-infrared (NIR) lanthanide complexes [(L)2 -Nd(NO3 )3 ] (L=TPE2 -BPY for 1, TPE-BPY for 2) by employing aggregation-induced emission (AIE)-active tetraphenylethylene (TPE) derivatives as sensitizers, which possessed matched energy to NdIII , prevented competitive deactivation under aggregation, even shifted the excitation window toward 600 nm by twisted intramolecular charge transfer. Furthermore, benefiting from the 4 f electron shielding effect and antenna effect, the enhanced excitation energies of the AIE-active sensitizers by structural rigidification transferred into the inert NdIII excited state through 3 LMCT, affording the first aggregation-induced phosphorescence enhancement (AIPE)-active discrete NIR-emitting lanthanide complexes. As 1 equipped with more AIE-active TPE than 2, L→Nd energy transfer efficiency in the former was higher than that in the latter under the same conditions. Consequently, the crystal of 1 exhibited one of the longest lifetimes (9.69 μs) among NdIII -based complexes containing C-H bonds.

The availability of polymorphs of metallic complexes provides an opportunity to reveal the relationship between crystal packing and catalytic activity. Herein, we immobilize two stable concomitant polymorphs (green NiL2-G and red NiL2-R) of mononuclear nickel NiL2 on electrodes as heterogeneous oxygen evolution reaction catalysts. Density functional theory calculations reveal that the formation of L2NiIV=O from L2NiIII-OH is the rate-determining step, whereas R-L2NiIII-OH is more stable than G-L2NiIII-OH, and forming L2NiIV=O from the former has a much lower barrier than from the latter. Consistently, NiL2-R exhibits a lower overpotential (339 mV) than NiL2-G (466 mV) at 10 mA cm−2.

Designing and constructing hierarchical and stimuli-responsive motorized nanocar systems to perform useful tasks on-demand is highly imperative towards molecular nanotechnology. In this work, a most simplified two-wheel nanocar was successfully prepared through a facile strategy of coordination-directed self-assembly. The nanocar meso-AgL2 features a central pseudo square-planar Ag(I) which was bridged by two enantiomeric motors as the wheels that ensure the car moves in the same direction when observed externally. Thanks to the electronic push–pull characteristic of L and 3ILCT triplet sensitization, this nanocar can be driven by visible light up to 500 nm. Furthermore, it could be disassembled into individual motor elements through the addition of pyridine, thus allowing dynamic regulation over the function of the nanocar. Importantly, our STM imaging results showed very organized tilted layered structures for meso-AgL2 on highly oriented pyrolytic graphite (HOPG) that are quite similar to its crystalline ones, paving the way for future single molecule manipulations. The nanocar reported here represents the first example of integrating individual motors into a hierarchical motorized nanocar system via the facile coordination-directed self-assembly method and may offer a good starting point to realize its robotic functions, e.g., metal transportation and release.

The nanoplatforms based on upconversion nanoparticles (UCNPs) have shown great promise in amplified photodynamic therapy (PDT) triggered by near-infrared (NIR) light. However, their practical in vivo applications are hindered by the overheating effect of 980 nm excitation and low utilization of upconversion luminescence (UCL) by photosensitizers. To solve these defects, core-satellite metal-organic framework@UCNP superstructures, composed of a single metal-organic framework (MOF) NP as the core and Nd3+-sensitized UCNPs as the satellites, are designed and synthesized via a facile electrostatic self-assembly strategy. The superstructures realize a high co-loading capacity of chlorin e6 (Ce6) and rose bengal (RB) benefitted from the highly porous nature of MOF NPs, showing a strong spectral overlap between maximum absorption of photosensitizers and emission of UCNPs. The in vitro and in vivo experiments demonstrate that the dual-photosensitizer superstructures have trimodal (magnetic resonance (MR)/UCL/fluorescence (FL)) imaging functions and excellent antitumor effectiveness of PDT at 808 nm NIR light excitation, avoiding the laser irradiation-induced overheating issue. This study provides new insights for the development of highly efficient PDT nanodrugs toward precision theranostics.

A new series of luminescent phosphine copper(I) complexes with cyano- and hydroxyl-substituted 2,2′-bipyridine ligands [CuI(bpy(CN)2)(P(PhX)3)2](ClO4) [X = H (1); Me (2); Cl (3)], [CuI(bpy(CN)2)(POP)](ClO4) (4), [CuI(bpy(OH)2)(PPh3)2](ClO4) (5) and [CuI(bpy(OH)2)(POP)](ClO4) (6) have been synthesized and characterized. Three of these complexes have been structurally characterized by using X-ray crystallography. The effect of the attaching –CN and –OH groups at the ortho-positions of bpy ligand was investigated. In CH2Cl2 solution, these complexes show yellow to orange phosphorescence, with the emission maxima not only sensitive to the electronic nature of the bipyridine ligands, but also considerably varied with the modification of phosphine ligands. In addition, these complexes show intense tunable green to yellow emissions in their solid state. To elucidate the electronic structures and transitions of these complexes, density functional theory (DFT) calculations on representative examples revealed that the lowest energy electronic transition associated with these complexes predominantly originates from metal-to-ligand charge transfer transitions (MLCT).

We prepared five diarylethenes containing 2-aryl-imidazole as the ethene bridge (L1–L5), and introduced response sites in imidazole rather than in the traditional appended aryl units to regulate their photochromism and thermal stability under acid stimulus. The results show that we can change the thermal stability from P- to T-type, and prevent their photoactivity by acidification, and it is clarified that the stronger the acid or the more acid added, the faster the decay rate of the diarylethene photostability. Furthermore, the prohibited photoactivity could be restored by neutralization with an equimolar amount of base.

The flexible ligand 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate (L2–) uses five of its six donor atoms in coordination through meridian, chelate, and terminal modes with MIIX2 to fo...

We report here the rare observation of a one-dimensional coordination polymer, {[Zn5(bit)4Cl6]·2(CH3CN)}n (1, Hbit = 1-methyl-2-(1H-1,2,3-triazol-4-yl)-1H-benzo[d]imidazole), having one mode of binding for the polytopic ligand and three different polyhedra, tetrahedron, square-base pyramid, and octahedron, for the metal node. The formation process of 1 involves the in situ decarboxylation of Hbitc (5-(1-methyl-1H-benzo[d]imidazol-2-yl)-1H-1,2,3-triazole-4-carboxylic acid) to Hbit. Apart from one bridging μ2-Cl, all the other chlorine atoms act as a terminal ligand to complete the polyhedra. While 1 is almost insoluble in most organic solvent, electrospray ionization mass spectrometry of its ultrasound-treated DMSO suspension found the two main species [Zn(bit)]+ at 0 eV and [Zn2(bit)3]+ at elevated in-source energies. Density functional theory calculation suggests a potential formation process involving the sequence: [Zn(bit)]+→ [Zn2(bit)3]+ + [Zn2(bit)2Cl]+ → [Zn3(bit)4Cl2]+. The luminescence intensity e...

A tandem reaction of pyridin-2-ylmethanamine (L1′) with 8-hydroxyquinoline-2-carbaldehyde (HL1) assisted by FeCl3 was observed to give the new nitrogen heterocycle HL3 (HL3=2-(imidazo[1,5-a]pyridin-3-yl)quinolin-8-ol) as its Fe(III) complex, [Fe(L3)Cl2] (Fel). Electrospray ionization mass spectrometry (ESI-MS) reveals its formation involves three steps: (1) coordination of both HL1 and Ll′ to Fe, (2) aldehyde-amine coupling, and (3) ring closure. The results of electronic absorption spectroscopy, cyclic voltammetry, and density functional theory (DFT) calculations show the proximity of the optical transition energy to that of the excitation of 3O2 to 1O2, which prompted us to explore its application as a photosensitizer for photodynamic therapy (PDT). Photo-toxicity studies show that Fel exhibits the highest anti-proliferation efficiency in human breast cancer MDA-MB-231 cells under light irradiation. Moreover, studies with orthotopic models of breast cancer further expounded the anti-tumor activity of Fe1 with no significant toxicity to other organs and low retention in the body.

For ethene derivatives with large groups the cis-isomer is often quite unstable and unavailable. Herein, we report an exception of two stable coordination complexes, (cis-L)ZnCl2 , starting from trans-1,2-bis(1-R-benzo[d]imidazol-2-yl)ethene (R=H, L1; R=CH3 , L2) ligands under solvothermal condition (T ≥140 °C). Using the intensity of the absorption and luminescence spectra as probes we proposed its progressive cis-to-trans reversal upon irradiation with UV light, which was confirmed by powder X-ray diffraction (PXRD). Similar results observed in the series of (cis-L2)MII Cl2 [M=Fe (4), Co (5), Ni (6)] demonstrate the universal strategy. The results of PXRD, NMR spectroscopy, ESI-MS and DFT calculations support the above conclusion. NMR spectroscopy indicates that irradiation of 1 converts an optimized 71 % of the cis-isomer to trans, whereas the free trans-L1 ligand transforms to only 15 % cis-isomer under similar conditions.

We designed two near-infrared (NIR) lanthanide complexes [(L)

The salts {[Ln2 Ln*(Hhmq)3 (OAc)3 (hfac)2 ]+ [Ln*(hfac)3 (OAc)(MeOH)]- } (Hhmq=2-methanolquinolin-8-oxide, hfac=hexafluoroacetylacetonate; Ln, Ln*=Er, Gd, Yb) feature a discrete heteronuclear cation consisting of two types of lanthanide atoms. The quinolinoxy O-atom serves as a μ2 -bridge to two Ln atoms and as a μ3 -bridge to all three atoms, with metal⋅⋅⋅metal distances being around 3.7 A. For 1 ([Yb2 Er]+ ), near-infrared downshifted luminescence is switched to competitive upconversion luminescence upon irradiation by a 980 nm laser under an extremely low excitation power (0.288 W cm-2 ) through introduction of fluoride ions. The stability of 1 after addition of fluoride was confirmed by powder X-ray diffraction and multistage mass spectrometry, associated with the 1 H NMR of 6 ([La2 Eu]+ ). More importantly, the at least 20-fold enhancement of the quantum yield in non-deuterated solvents at room temperature under low power densities (2 W cm-2 ) is the highest among the few molecular examples reported.

The conjugation of bridging bis(diphenylphosphine oxide) alkane or arene ligands was found to control the structural dimensionality and the emission color of complexes from reactions with SmIII(hfac)3(H2O)2 (hfac− = hexafluoroacetylacetonato) while retaining the Sm⋯Sm distances. Bis(diphenylphosphine oxide)-1,4-butane (L1) affords a one-dimensional (1D) ribbon {Sm(hfac)3(L1)}∞ (1) that emits red color, while bis(diphenyl-phosphinoyl)-1,4-benzene (L2) results in a two-dimensional (2D) network {Sm(hfac)2(CF3COO)(L2)3}∞ (2) and near-white emission, but bis(diphenyl-phosphinoyl)-9,10-anthracene (L3) forms a zero-dimensional (0D) cyclic structure {Sm(hfac)3(L3)}2 (3) with strong π⋯π interactions that emit green color. Noticeably, the conjugation change is accompanied by a configurational change of coordination from trans for 1 and 2 to cis for 3. The color change is associated with the superposition of ligand and Sm based electronic band energies and their intensities. Such white light emission by a single compound having contributions from different building components is quite rare.

Ca10M(PO4)7:Eu (M = Li, Na, K) phosphors have been synthesized via a solid-state reaction process, their phase purity was examined using XRD patterns, and Rietveld refinement confirmed that the Ca10Li(PO4)7, Ca10Na(PO4)7 and Ca10K(PO4)7 are pure phases. The photoluminescence properties of the Ca10M(PO4)7:Eu (M = Li, Na, K) phosphors showed that the self-reduction of Eu3+ to Eu2+ can occur in an air atmosphere. Eu3+ ions can be reduced to Eu2+ ions when doped in Ca10Li(PO4)7, Ca10Na(PO4)7 and Ca10K(PO4)7 crystals, which was detected using photoluminescence spectra. In this work, the bond energy method was used to determine and explain the mechanism of site occupation of Eu entering the host matrix. According to the calculated value of the deviation of bond energy for Eu3+-doped Ca10M(PO4)7 (M = Li, Na, K) crystals, the similar value between and , and , and and can provide the conditions for the self-reduction of Eu3+ in the Ca10M(PO4)7 (M = Li, Na, K) system. Meanwhile, the smaller deviation values of , , and in Ca10Li(PO4)7, Ca10Na(PO4)7, and Ca10K(PO4)7 crystals and in Ca10K(PO4)7 crystals indicated that the preferential sites of Eu ion occupancy in the Ca10M(PO4)7 (M = Li, Na, K) lattices are Li, Na, K and Ca sites. The conclusions obtained from the calculated results of the bond energy method are consistent with the Rietveld refinement and the photoluminescence spectra of Ca10M(PO4)7 (M = Li, Na, K).

Using a facile one-step hydrothermal method, a series of metal-organic frameworks containing Gd/Tm (Gd/Tm-MOFs) were prepared successfully. Through the mutual activation of Gd3+ and Tm3+, Gd/Tm-MOFs showed unexpected excellent up-conversion luminescence (UCL) and a superior positive magnetic resonance image (MRI). Using doxorubicin hydrochloride (DOX) as a drug model, the feasibility of Gd/Tm-MOFs as a multifunctional drug carrier was demonstrated. Through modifying Gd/Tm-MOFs with uniform mesoporous silica (mSiO2) shells and folic acid (FA), the drug loading was improved up to 41.5 mg g-1, and pH responsive drug release increased to 64% from 12% by regulating the pH from 5.8 to 7.4. Also, the particles were tracked by MRI, and the second highest longitudinal relaxivity (r1) among the reported gadolinium complexes of 225.86 mM-1 s-1 was achieved. The cell imaging shows obvious blue and red luminescence under 980 nm laser excitation, and the up-conversion luminescence is unique because there is no autofluorescence from cells under 980 nm excitation. This indicates their promising application in the biological field. All the experiments indicate the promising application of Gd/Tm-MOFs in diagnosis and treatment.

The assembly sequence of the coordination cluster [Zn5 (H2 L(n) )6 ](NO3 )4 ]⋅8 H2 O⋅2 CH3 OH (Zn5 , H3 L(n) =(1,2-bis(benzo[d]imidazol-2-yl)-ethenol) involves in situ dehydration of 1,2-bis(benzo[d]imidazol-2-yl)-1,2-ethanediol (H4 L) through the formation of the [Zn(H3 L)2 ](+) monomer, dimerization to [Zn2 (H3 L)2 ](+) , dehydration of the ligand to [Zn2 (H2 L(n) )2 ](+) , and the final formation of the pentanuclear cluster. The cluster has the following special characteristics: 1) high stability in both refluxing 37 % HCl and 27 % NH3 , 2) low cytotoxicity, and 3) pH-sensitive fluorescence in the visible-to-near-infrared (Vis/NIR) region in the solid state and in solution. We have applied it as a fluorescent probe both in vivo and in vitro. Its H-bonding ability is the key to its affinity and selectivity for imaging lysosomes in HeLa cells and tumors in male BALB/C mice. It provides a new type of sensitive and biocompatible fluorescent probe for detecting small tumors (13.5 mm(3) ).

Crystal transformation between two polymorphs (green, 1-G, and red, 1-R) of the square-planar nickel complex NiL2 (L = 2-ethoxy-6-(N-methyliminomethyl)phenolate) and their tuning effect to semiconductor properties were studied both experimentally and theoretically. When 1-G is heated to 413 K, it converts to 1-R, whereas soaking 1-R in several kinds of solvents causes it to revert to 1-G. Crystallographic and PXRD studies reveal the dramatic changes in crystal dimensions due to the changes of packing models. Heating device made from 1-G (D-1-G(298)) at 413 K significantly increases the electrical conductivity from 6.55 × 10–4 S cm–1 for D-1-G(298) to 1.11 × 10–3 S cm–1 for D-1-G(413), showing significant crystal form dependence. Heat-treating D-1-G and D-1-R devices at different temperatures clearly reveals the reason for the conductivity tuning. Thus, the conductivity of NiL2-based devices could be well tuned through crystal transformation by heating or by soaking in solvent. Theoretical calculations cle...

The conjugation of bridging bis(diphenylphosphine oxide) alkane or arene ligands was found to control the structural dimensionality and the emission color of complexes from reactions with SmIII(hfac)3(H2O)2 (hfac- = hexafluoroacetylacetonato) while retaining the SmSm distances. Bis(diphenylphosphine oxide)-1,4-butane (L1) affords a one-dimensional (1D) ribbon {Sm(hfac)3(L1)}∞ (1) that emits red color, while bis(diphenyl-phosphinoyl)-1,4-benzene (L2) results in a two-dimensional (2D) network {Sm(hfac)2(CF3COO)(L2)3}∞ (2) and near-white emission, but bis(diphenyl-phosphinoyl)-9,10-anthracene (L3) forms a zero-dimensional (0D) cyclic structure {Sm(hfac)3(L3)}2 (3) with strong ππ interactions that emit green color. Noticeably, the conjugation change is accompanied by a configurational change of coordination from trans for 1 and 2 to cis for 3. The color change is associated with the superposition of ligand and Sm based electronic band energies and their intensities. Such white light emission by a single compound having contributions from different building components is quite rare.

The newly synthesized ionic triple salt Ru–Er, {[RuII(bpy)2(dbim)][ErIII(hfac)4][CF3COO]·H2O} (bpy = 2,2′-bipyridine; hfac− = hexafluoroacetylacetonate; dbim = 2,2′-dibenzimidazole) exhibits near-infrared (NIR) emission at 1535 nm by intermolecular Ru → Er (d → f) energy transfer across supramolecular interactions when pumped within the Ru(II) 3MLCT band. It is the first such observation for a transition metal–lanthanide ionic pair.

Information of solid-state and solution structures is crucial in the characterization of molecular clusters and in advancing the understanding of their diverse properties. [Et

Heterotetranuclear geometrical (Er2Yb2/Yb2Er2) and configuational (EuTb3/Eu3Tb) isomeric lanthanide(III) complexes have been synthesized and characterized by spectroscopy as well as X-ray crystallography. The geometric Er2Yb2/Yb2Er2 isomers exhibit dual emissions from both erbium(III) and ytterbium(III) ions. For the EuTb3/Eu3Tb configurational isomers, the TbIII subunits transfer energy to the EuIII centers in the EuTb3 complex, whereas the TbIII ion in the TbEu3 complex serves mainly as a structural stabilizer.

In order to reuse the waste originated from poly(phenylene sulfide) (PPS) production in stead of combustion, the oligomeric materials in the waste were recovered as raw materials. The recovered materials, then, were used to react with sulfur in molten state to produce polymeric resin. The structure and thermal property of oligomeric materials and their derived polymer were characterized by elemental analysis, infrared spectroscopy, X-ray diffraction and differential scanning calorimetry. The results showed that oligomeric materials are a series of PPS oligomers, and their derived polymer is poly(arylene sulfide)s (PAS). The thermal transition temperatures of obtained PAS are higher than those of PPS oligomers, which are attributed to the increase of molecular weight. It is desired that the yielding PAS has potential applications as plastic, coating, or filler materials.

Hydrothermal reactions of zinc(II) or cadmium(II) salts with o-sulfophenylarsonic acid (o-HO3S-C6H4-AsO3H2, H3L) afforded two layered compounds, namely, [Zn2(L)(OH)(H2O)]·H2O (1) and [Cd3(L)2(H2O)3]·H2O (2). Introduction of 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), and 2,2′:6′,2′′-terpyridine (terpy) as auxiliary chelating ligands led to a series of zinc(II) or cadmium(II) sulfonate-arsonates with lower dimensional aggregations, namely, [Zn(HL)(bipy)2]2·6H2O (3), [Cd(HL)(bipy)]2 (4), [Zn(HL)(phen)]2·2H2O (5), [Cd(HL)(phen)(H2O)]2[Cd(HL)(phen)]2 (6), [Cd(HL)(phen)]2·2H2O (7), [Zn(HL)(terpy)]2 (8), [Cd(HL)(terpy)]2·2H2O (9), Zn(HL)(bipy) (10), Zn(HL)(bipy)·2H2O (11), and Zn(HL)(phen)·H2O (12). Compound 3 contains two mononuclear cluster units, whereas 4–9 feature five types of dinuclear cluster units in which a pair of Zn2+ or Cd2+ ions are interconnected by two sulfonate-arsonate ligands (via M–O–M, M–O–As–O–M and M–O–S–O–M bridges). Compounds 10 and 11 feature a one-dimensional (1D) chain in which each pair of Zn2+ centers are bridged by one arsonate group of a sulfonate-arsonate ligand. In compound 12, dinuclear clusters and 1D chains coexist. All twelve compounds display very strong fluorescence in the ultraviolet or blue light region.

Stroke is a major public health problem leading to high rates of death and disability in adults. Excessive stimulation of N-methyl-D-aspartate receptors (NMDARs) and the resulting neuronal nitric oxide synthase (nNOS) activation are crucial for neuronal injury after stroke insult. However, directly inhibiting NMDARs or nNOS can cause severe side effects because they have key physiological functions in the CNS. Here we show that cerebral ischemia induces the interaction of nNOS with postsynaptic density protein-95 (PSD-95). Disrupting nNOS-PSD-95 interaction via overexpressing the N-terminal amino acid residues 1-133 of nNOS (nNOS-N(1-133)) prevented glutamate-induced excitotoxicity and cerebral ischemic damage. Given the mechanism of nNOS-PSD-95 interaction, we developed a series of compounds and discovered a small-molecular inhibitor of the nNOS-PSD-95 interaction, ZL006. This drug blocked the ischemia-induced nNOS-PSD-95 association selectively, had potent neuroprotective activity in vitro and ameliorated focal cerebral ischemic damage in mice and rats subjected to middle cerebral artery occlusion (MCAO) and reperfusion. Moreover, it readily crossed the blood-brain barrier, did not inhibit NMDAR function, catalytic activity of nNOS or spatial memory, and had no effect on aggressive behaviors. Thus, this new drug may serve as a treatment for stroke, perhaps without major side effects.

Eight new lanthanide(III) complexes, {Ln(hfac)3}2(μ-HMq)2 (Ln = Eu, 1; Tb, 2; Yb, 3; hfac− = hexafluoroacetylacetonate; HMq = 2-methyl-8-hydroxylquinoline), {Eu(hfac)2(H2O)-(OC6H4CN)}2(μ-HMq)2 (4, HOC6H4CN = 4-hydroxybenzonitrile), Er5(hfac)9(μ-HMq)2(μ4-CH3COO)2(μ3-CH3COO)(μ-CH3COO)(μ3-OH)2 (5), and Cr(Mq)(μ-HMq)(μ3-OH)(μ-OH)(μ-CH3COO)2{Ln(hfac)2}2 (Ln = Eu, 6; Tb, 7; Er, 8), with bridging HMq in the μ-phenol mode were synthesized and characterized by X-ray crystallography, except for 6. Each LnIII center in 1−4 is surrounded by eight O donors to form a distorted square-antiprism, except that two O binding sites from one hfac− in 1−3 are displaced by one H2O and one OC6H4CN− in 4. Complex 5 could be viewed as a combination of two {Er(hfac)2}2(μ-HMq) moieties linked to a central ErIII ion through bridging acetates and μ3-OH, in which the central ErIII ion is nine-coordinated to give a distorted capped square antiprism whereas the other four ErIII ions are eight-coordinated with approximate square antiprism...

A novel initiator system, benzyl chloride / 1-octanol-substituted MoCl5 / triphenyl phosphine (PPh3), was applied to the atom transfer radical polymerizations (ATRP) of both butadiene and styrene as well as their copolymerization. Characterization revealed a linear increase in the number average molecular weight with monomer conversion and rather wide molecular weight distributions of the polymerization products. Increasing the polymerization temperature promoted the reaction rate and narrowed the polydispersity index of polystyrene proportionally. The polymerization rule for butadiene catalyzed by the above Mo-based system catalyst is similar to that of styrene. The microstructure of the butadiene was investigated by IR and 1H NMR. IR, 13C NMR and DSC measurements showed that the butadiene and styrene copolymer was a random copolymer. The chlorine atom at the ω end group of the polymer and the change in the valence state of molybdenum, as explored by UV-Vis spectroscopy, revealed that the polymerization proceeded in a manner closest to the mechanism of ATRP.

Heterotetranuclear Zn(2)Ln(2) (Ln = Nd , Eu , Sm , Er , Yb ) complexes {Zn(2)(Mq)(2)(tpyO)(2)}{(Ln(hfac)(3))(2)} (HMq = 2-methyl-8-hydroxylquinoline, tpyOH = [2,2':6'2'']terpyridin-4'-ol, hfac = hexafluoroacetylacetonate) display novel square structures ligated by bifunctional ligands tpyO (mono- and tridentate) and Mq (chelating and bridging mu-phenoxo). These compounds exhibit sensitized lanthanide emission upon photo-excitation of ZnMq/tpy antenna chromophores. By virtue of the dual luminescence with complementary colors, the ZnMq/tpyO-based cyan emission and Sm(III)-centered orange luminescence are combined to generate a white-light emission in Zn(2)Sm(2) (4) complex.

Reaction of (CH3)3SiC≡Cbpy (bpy = 2,2′-bipyridyl), (CH3)3SiC≡CC6H4tpy (tpy = 2,2′:6′2′′-terpyridyl), or (CH3)3SiC≡CC6H4C≡Cbpy with Pt(But2bpy)Cl2 in the presence of KF and CuI gave Pt(But2bpy)(C≡Cbpy)2 (1), Pt(But2bpy)(C≡CC6H4tpy)2 (5), or Pt(But2bpy)(C≡CC6H4C≡Cbpy)2 (9), respectively. Incorporating Ln(hfac)3 (Ln = Nd, Er, Yb; hfac = hexafluoroacetylacetonate) units with 1, 5, and 9 through 2,2′-bipyridyl/2,2′:6′2′′-terpyridyl chelation induces isolation of a series of PtLn2 heterotrinuclear complexes. Upon excitation of the PtLn2 complexes at 350 nm ≤ λex ≤ 500 nm, near-infrared (NIR) luminescence from lanthanide ions is indeed “lighting up” through effective Pt → Ln energy transfer from 3[d(Pt) → π*(But2bpy)] metal-to-ligand charge transfer transition excited-state of the Pt(But2bpy)bis(acetylide) antenna chromophore. By successive insertion of phenylene or ethynyl between acetylide and 2,2′-bipyridyl/2,2′:6′,2′′-terpyridyl in the bridging ligands, the rate and efficiency of Pt → Ln energy transfer are ...

Reaction of polymeric gold(I) acetylide species (bpyC[triple bond]CAu)n (bpyC[triple bond]CH = 5-ethynyl-2,2'-bipyridine) with diphosphine ligands Ph2P(CH2)nPPh2 (n = 2-6) or 1,1'-bis(diphenylphosphino)-ferrocene (dppf) in dichloromethane induces isolation of binuclear gold(I) complexes (bpyC[triple bond]CAu)2{mu-Ph2P(CH2)nPPh2} or (bpyC[triple bond]CAu)2(mu-dppf). Complexation of Ln(hfac)3 (hfac = hexafluoroacetylacetonate, Ln = Nd, Eu, Er, Yb) subunits to the binuclear gold(I) complexes through 2,2'-bipyridyl chelation gives the corresponding Au4Ln4 or Au2Ln2 heteropolynuclear complexes. Noticeably, upon formation of the Au4Ln4 arrays by complexation of (bpyC[triple bond]CAu)2(mu-Ph2P(CH2)4PPh2) (3) with Ln(hfac)3 units, trans-conformation in 3 transforms dramatically to the cis-arranged form due to the strong driving force from ligand-unsupported Au-Au contacts between two Au2Ln2 subunits. In contrast, cis-conformation in (bpyC[triple bond]CAu)2(mu-dppf) (6) stabilized by Au-Au interactions is reversed to the trans-oriented form upon formation of Au2Ln2 arrays by introducing Ln(hfac)3 units through 2,2-bipyridyl chelation. The binuclear gold(I) complexes show bright blue luminescence featured by ligand-centered pi --pi* (C[triple bond]Cbpy) states together with low-energy emission at 500-540 nm, associated with 3(pi--pi*) excited states, mixed probably with some characteristic from (Au-Au) --(C[triple bond]Cbpy) 3MMLCT transition. For Au4Ln4 or Au2Ln2 complexes, sensitized lanthanide luminescence is achieved by energy transfer from Au-acetylide chromophores with lifetimes in the sub-millisecond range for EuIII complexes, whereas in the microsecond range for near-infrared emitting NdIII, ErIII, and YbIII species.

Reaction of cis- or trans-Pt(PPh3)2Cl2 (PPh3 = triphenylphosphine) with 5-[2-(trimethylsilyl)-1-ethynyl]-2,2′-bipyridine (bpyC≡CSiMe3) gave cis-Pt(PPh3)2(C≡Cbpy)2 (1) or trans-Pt(PPh3)2(C≡bpy)2 (5). Incorporating 1 or 5 with Ln(hfac)3(H2O)2 (hfac = hexafluoroacetylacetonate) induced formation of the corresponding cis- or trans-PtLn2 heterotrinuclear complexes cis-Pt(PPh3)2{(C≡Cbpy)Ln(hfac)3}2 (Ln = Nd 2, Eu 3, Yb 4) or geometrical isomers trans-Pt(PPh3)2{(C≡Cbpy)Ln(hfac)3}2 (Ln = Nd 6, Eu 7, Yb 8). As verified through 31P NMR characterization as well as determination of the structures of 1, 4, and 8 by X-ray crystallography, the cis- or trans-arranged forms around PtII centers remain unchanged in both solutions and solid states without thermal or light-induced isomerization during the reactions. With excitation at 360 < λex < 450 nm, which is the absorption region of metal-perturbed π→π* (C≡C) transitions and dπ(Pt)→π*(C≡Cbpy) MLCT transition, sensitized lanthanide luminescence occurs with a microsecond r...

Five new lead(II) sulfonate-phosphonates, namely [Pb(3)(L)(2)(H(2)O)(2)]center dot 4H(2)O (1), [Pb(HL)(phen)]center dot H(2)O (2), [Pb(6)(L)(4)(phen)(8)]center dot 3H(2)O (3), [Pb(6)(L)(4)(phen)(10)]center dot 2H(2)O (4), and [Pb(6)(L)(4)(4,4'-bipy)(H(2)O)(2)]center dot 2H(2)O (5; H(3)L = m-HO(3)S-C(6)H(4)-PO(3)H(2), phen = 1,10-phenanthroline, 4,4'-bipy = 4,4'-bipyridine) have been prepared and structurally characterized. Compound I features a novel 3D framework in which 1D chains of Pb(3)O(4) cluster units are further bridged by sulfonate-phosphonate ligands, whereas compound 2 features a layer structure in which 1D chains of Pb(2)O(4) clusters are further bridged by sulfonate-phosphonate ligands. Compounds 3 and 4 represent the first zero-dimensional lead(II) phosphonates and feature novel isolated hexanuclear lead(II) clusters in which six Pb(II) ions are bridged by two tetradentate and two pentadentate phosphonate groups. Compound 5 features a 3D framework that is similar to that in compound 1 despite the different coordination modes for some sulfonate groups of the ligands. The main difference is that an aqua ligand in compound 1 is replaced by a nitrogen atom of the 4,4'-bipy ligand, which results in the splitting of the large cavities in compound I into two small apertures in compound 5. Compounds 1 and 5 exhibit strong broad blue fluorescent emission bands at 398 and 420 nm, respectively. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheirn, Germany, 2007).

Incorporation of diplatinum component [Pt2(μ-dppm)2(C Cbpy)4] (1, dppm = Ph2PCH2PPh2, C Cbpy = 2,2′-dipyridyl-5-acetylide) with Re(CO)5Cl, Ru(bpy)2Cl2 (bpy = 2,2′-bipyridine) and Gd(hfac)3(H2O)2 (Hhfac = hexafluoroacetylacetone) via 2,2′-dipyridyl chelating induced isolation of Pt 2 II Re 4 I (2), Pt 2 II Ru 4 II (3), and Pt 2 II Gd 2 III (4) complexes, respectively. The structures of 2 and 4 were determined by X-ray single crystal diffraction. Intense low-energy absorptions occur in the range 360–510 nm originating from metal-to-ligand charge transfer (MLCT) transitions. These compounds display photoluminescence in both solid states and dichloromethane at room temperature with emissive lifetimes in the range of microseconds.

Hydrothermal reactions of zinc(II) carbonate with m-sulfophenylphosphonic acid (m-HO3S-Ph-PO3H2) and 1,10-phenanthroline (phen) or 4,4'-bipyridine (bipy) lead to three novel zinc(II) sulfonate-phosphonates, namely, [Zn(phen)3]2[Zn4(m-O3S-Ph-PO3)4(phen)4].20H2O (1), [Zn6(m-O3S-Ph-PO3)4(phen)8].11H2O (2), and [Zn6(m-O3S-Ph-PO3)4(bipy)6(H2O)4].18H2O (3). Compound 1 contains a tetranuclear zinc(II) cluster anion in which four Zn(II) ions are bridged by two tetradentate and two bidentate phosphonate groups, and the four negative charges of the cluster are compensated by two [Zn(phen)3]2+ cations. Compound 2 features a hexanuclear zinc(II) cluster in which the same tetranuclear cluster of 1 is bridged with two additional Zn(II) ions. The structure of 3 features a porous 3D network based on hexanuclear zinc(II) units of [Zn6(m-O3S-Ph-PO3)4] interconnected by 4,4'-bipy ligands. The hexanuclear cluster in 3 is different from that in 2 in that all four phosphonate groups in 3 are tridentate bridging. Compounds 1, 2, and 3 exhibit broad blue fluorescent emission bands at 378, 409, and 381 nm, respectively.

Tin containing mesoporous silicas with various tin contents were prepared by reaction of tetrabutyl tin with the surface silanol groups of calcined MCM-41 followed by thermal treatment under oxygen. Various physicochemical methods (XRF, FTIR, XRD, HRTEM, N 2 adsorption, UV–vis spectroscopy, …) and the catalytic hydroxylation of phenol by H 2 O 2 were used to characterize the resulting materials. It is shown that the materials prepared by this way have a better hydrothermal stability and a higher catalytic activity than tin containing MCM-41 prepared by conventional methods (mechanical mixture of nano-sized SnO 2 and MCM-41, impregnation of MCM-41 by SnCl 4 or hydrothermal synthesis).

By virtue of versatile coordination modes of 8-hydroxyquinoline and acetate, a new mixed lanthanide complex Er4Yb, {[Er2(hfac)4(μ3-CH3COO)(μ3-OH)]2}{μ-HMq}2{Yb(hfac)(μ4-CH3COO)2} (hfac− = hexafluoroacetylacetonate; HMq = 2-methyl-8-hydroxyquinoline) was isolated. The luminescence measurements show that upon irradiation with [n → π*] absorption of HMq at λex = 400 nm, “dual emission” from both erbium (III) and ytterbium (III) has been achieved, respectively.

A new bimetallic complex [HNEt3][Cuq2IEu(hfac)3] (q− = 8-hydroxyquinolinato, hfac− = hexafluoroacetylacetonate) was prepared simply with only one step and characterized. Upon excitation of the organic ligand q−, the sensitized europium luminescence was achieved.

The preparation, characterization and photophysical properties of heterobinuclear complexes {Pt(C^N^N)(C Cbpy)}Ln(hfac)3 (C^N^N = 2-(6-(naphthalen-3-yl)-4-phenylpyridin-2-yl)pyridine; HC Cbpy = 5-ethynyl-2,2′-bipyridine; Ln = Nd, Eu, Yb; hfac = hexafluoroacetylacetonate) are described. With excitation at 390 ⩽ λex ⩽ 500 nm which is the MLCT/LLCT absorption region of the Pt(C^N^N)(C Cbpy) chromophore, lanthanide luminescence is successfully attained by Pt → Ln energy transfer from the platinum(II) antenna chromophore to the lanthanide center across the bridging C Cbpy ligand.

The synthesis, crystal structure and photophysical properties of [Tb{Tb4(hpmba)8(μ3-ΟΗ)4(μ4-ΟΗ)}2OH] (hpmba = 2-hydroxy-N-((pyridin-2-yl)methyl)benzamide) was presented. The crystal structure exhibits a novel sandglass-like nonanuclear structure. The complex is strongly emissive with the lifetime about 1.02 ms at 546 nm in CH3CN at 298 K. The ITO/PVK/complex/Al OLED with the compound as a light-emitting material has also been fabricated; it has a maximum electroluminescence intensity when the driving voltages were increased to 11 V.

A new complex Nd2(hfac)6(CH3COO)2 {12[ane]HN4(CH2C CH)4}2 (hexafluoroacetylacetonate, hfac) was synthesized and characterized. Upon excitation of the organic cation {12[ane]N4H(CH2C CH)4}+ (protonation on one of the nitrogen atoms of N,N′,N′,N‴-tetra-(3-prop-1-yne)-1,4,7,10-tetrazacyclododecane), the neodymium NIR luminescence is sensitized through Forster energy transfer mechanism.