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Photoactivatable probes can switch fluorescence on from a weak or nonemission state to improve the sensitivity of the sensing system. In this work, we successfully constructed three highly emissive photoactivatable probes, 2-DP, 1-2-DP and 2-2-DP, for Cu 2+ detection. Under UV irradiation, the photoluminescence quantum yields of 2-DP, 1-2-DP and 2-2-DP display approximately 52.4-, 11.5- and 49.2-fold enhancement, respectively. Cu 2+ selectively quenches the bright photoactivated fluorescence, resulting in an approximately 38-fold fluorescence reduction. The highly selective fluorescence response to Cu 2+ yields an excellent low detection limit of 5.8 nM. Moreover, the photoactivatable probes were successfully applied for Cu 2+ determination in tap water and tea samples with recovery ranges of 95%-105% and 97%-106%, respectively. This work provides a more sensitive and efficient methodology for Cu 2+ detection in heavy metal pollution and food safety., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Triethylamine (TEA) is an effective medium for inhibiting dye aggregation and improving the luminescence of dye-sensitized lanthanide-doped upconversion nanoparticles (UCNPs). However, excessive TEA will cause quenching of upconversion luminescence. In this paper, the possible mechanism of TEA affecting upconversion luminescence is discussed. It is found that TEA can enhance the nucleophilicity of the solvent, leading to dye shedding from the nanoparticles. Reducing the dielectric constant of the solvent can make TEA play a more positive role in upconversion luminescence and photostability of dye-sensitized UCNPs. When heptanol is selected as the solvent for CyBSO-sensitized β-NaYF 4 :20%Yb 3+ ,2%Er 3+ (UNs), TEA can increase the upconversion luminescence by 6.0 times relative to that in methanol. More importantly, the optimal content of TEA in heptanol is 3700 times more than that in methanol. Under the action of large amounts of TEA in heptanol, a novel upconversion nanoprobe for detecting ascorbic acid is developed with a limit of detection of 0.103 μM and high selectivity over potential interfering species. Meanwhile, the high concentration of TEA in heptanol can improve the photostability of CyBSO-sensitized UNs by 10.4 times, which is of paramount importance for the practical application of dye-sensitized UCNPs.

A series of new magnesium bismuth Zintl phases, A 14 MgBi 11 (A = Ca, Sr, Eu), have been synthesized, and their thermoelectric properties were systematically evaluated. These novel phases belong to the well-known Yb 14 MnSb 11 family, whose structure adopts the tetragonal space group I4 1 /acd (No. 142) with cell parameters of a = 17.0470(17)/17.854(2)/17.6660(7) Å and c = 22.665(5)/23.580(6)/23.2446(18) Å for Ca 14 MgBi 11 , Sr 14 MgBi 11 , and Eu 14 MgBi 11 , respectively. Without intentional optimization, these materials exhibit high potential as new thermoelectric candidates. Especially for Sr 14 MgBi 11 , a high zT value of 0.72 has been approached at 1073 K. The discovery of these new Zintl series is very interesting, which implies the high possibility of extending the 14-1-11 thermoelectric system to the bismuth analogues in the development of highly efficient thermoelectric materials. Density functional theory (DFT) calculations were incorporated as well to help better understand the properties of these important compounds.

A picosecond (ps) mid-infrared (MIR) optical parametric amplifier (OPA) with LiInSe 2 crystal was demonstrated for the first time. The MIR OPA was pumped by a 30 ps 1064 nm Nd:YAG laser and injected by a barium boron oxide (BBO)-based widely tunable near-infrared seed. A maximum idler pulse energy of 433 μJ at 4 μm has been obtained under a pump energy of 17 mJ, and the corresponding pulse duration was estimated to be ~13 ps. To our knowledge, this is the highest single pulse energy generated by LiInSe 2 crystal. Furthermore, an idler spectrum tuning from 3.6 to 4.8 μm was investigated at fixed pump energy of 15 mJ.

New Mg-containing antimonide Zintl phases, Sr 14 MgSb 11 and Eu 14 MgSb 11 , were synthesized from high-temperature solid-state reactions in Ta tubes at 1323 K. Their structures can be viewed as derived from the Ca 14 AlSb 11 structure type, which adopt the tetragonal space group I4 1 /acd (No. 142, Z = 8) with the cell parameters of a = 17.5691(14)/17.3442(11) Å and c = 23.399(4)/22.981(3) Å for the Sr- and Eu-containing compounds, respectively. The corresponding thermoelectric properties were probed, which demonstrated high potential of these compounds as new thermoelectrics for their very low thermal conductivity and moderate Seebeck coefficient. Magnetism studies and theoretical calculations were conducted as well to better understand the structure-and-property correlation of these materials.

Two new chiral Zintl compounds, Sr14Sn3As12 and Eu14Sn3As12, were synthesized from tin-flux reactions, and the structures were determined by using single-crystal X-ray diffraction. Both compounds crystallize in the trigonal space group R3 (No. 146, Z = 3) with the anion structures containing various units: dumbbell-shaped [Sn2As6](12-) dimers, [SnAs3](7-) triangular pyramids, and isolated As(3-) anions. Very interestingly, these two compounds exhibit opposite chirality in the observed crystal structures, resembling enantiomorphs. Detailed structure analyses suggest possible steric effects among the anion clusters, and on the basis of the calculated electronic structures, substantial electron lone pairs exist on the anions of both compounds, which may provide a hint to understanding the origination of chirality in these intermetallic compounds.

The title compound, penta-barium tetra-indium hexa-anti-mony, was synthesized by an indium-flux reaction and its structure features layers composed of edge-sharing In2Sb6 units. The voids between the In4Sb6 layers are filled by Ba(2+) cations, which are all surrounded by six Sb atoms and form bicapped octa-hedral or triangular prismatic coordination geometries. There are five barium ions in the asymmetric unit: one has no imposed crystallographic symmetry, two lie on mirror planes and two have mm2 point symmetry. The two In atoms and four Sb atoms in the asymmetric unit all lie on general crystallographic positions.

The focus of this article is on the synthesis and structural characterization of the new ternary antimonides Eu(9)Cd(4+x)Sb(9) and Ca(9)Mn(4+x)Sb(9) (x ≈ (1)/2). Although these compounds have analogous chemical makeup and formulas, which may suggest isotypism, they actually belong to two different structure types. Eu(9)Cd(4.45(1))Sb(9) is isostructural with the previously reported Eu(9)Zn(4.5)Sb(9) (Pbam), and its structure has unit cell parameters a = 12.9178(11) Å, b = 23.025(2) Å, and c = 4.7767(4) Å. Ca(9)Mn(4.41(1))Sb(9) crystallizes in the orthorhombic space group Pnma with unit cell dimensions a = 12.490(2) Å, b = 4.6292(8) Å, and c = 44.197(8) Å and constitutes a new structure type. The two structures are compared and contrasted, and the structural relationships are discussed. Exploratory work aimed at the arsenic-based analogues of either type led to the identification of Ca(9)Zn(4.46(1))As(9), forming with the latter structure [a = 11.855(2) Å, b = 4.2747(8) Å, and c = 41.440(8) Å]. Differential thermal analysis and electrical resistivity measurements, performed on single crystals of Ca(9)Zn(4+x)As(9), indicate high thermal stability and semiconducting behavior. Magnetic susceptibility measurements on Eu(9)Cd(4+x)Sb(9) samples confirm the expected Eu(2+) ([Xe]4f(7)) ground state.

Four new quaternary chalcogenides, Ba4AgGaS6 (1), Ba4AgGaSe6 (2), Ba4CuInS6 (3), and Ba4AgInS6 (4), were synthesized by solid-state reactions and their structures were characterized through single-crystal X-ray diffraction. In spite of their similar chemical compositions, the flexible arrangement between the transition metals and the triel atoms leads to subtle differences in their polyanion structures. All structures feature similar [MTrQ6](8-) 1D polyanionic chains (M=Cu, Ag; Tr=Ga, In; Q=S, Se), which are constructed from corner-sharing MQ4 or TrQ4 tetrahedra. However, the transition metals and triels are mixed in 1, 2, and 3, but they occupy independent crystallographic sites in 4. As a result, compounds 1-3 belong to the known Ba2CoS3 (Pnma No. 62) or Ba2 MnS3 (Pnma No. 62) class, whereas 4 crystallizes in its own structural type within the monoclinic P2₁/c (No. 14) space group. The structural relationship among these new phases was also studied with the aid of DFT calculations and related optical properties are presented as well., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new quaternary arsenide Zintl phase, Ba13Si6Sn8As22, has been synthesized from the Sn-flux reactions, and the structure was determined by the single-crystal X-ray diffraction methods. The compound crystallizes in the tetragonal non-centrosymmetric space group I42m (No. 121) with unit cell parameters of a = b = 14.4857(3) Å, c = 13.5506(7) Å, V = 2843.40(17) Å(3). Its polyanion structure can be viewed as composed of [Si4As10] adamantane-like clusters and SiAs4 tetrahedra, which are linked via the [Sn2As4] groups built through two edge-sharing SnAs3 triangular pyramids. Differential thermal analysis and thermogravimetry measurements indicate that Ba13Si6Sn8As22 has good thermal stability, and does not melt or decompose below 1045 K under Ar atmosphere. Density functional calculations were performed on Ba13Si6Sn8As22 and the results suggest a band gap of around 1.0 eV for Ba13Si6Sn8As22, confirmed by the diffuse reflectance spectrum measurement. In addition, the extensively existing lone pairs of electrons on the p-orbitals of As and Sn may also hint interesting nonlinear optical properties considering the noncentrosymmetric structure.

Three new anthracene derivatives [2-chloro-9,10-dip-tolylanthracene (DTACl), 9,10-dip-tolylanthracene-2-carbonitrile (DTACN), and 9,10-di(naphthalen-1-yl)anthracene-2-carbonitrile (DNACN)] were synthesized as triplet acceptors for low-power upconversion. Their linear absorption, single-photon-excited fluorescence, and upconversion fluorescence properties were studied. The acceptors exhibit high fluorescence yields in DMF. Selective excitation of the sensitizer Pd(II)octaethylporphyrin (PdOEP) in solution containing DTACl, DTACN, or DNA-CN at 532 nm with an ultralow excitation power density of 0.5 W cm(-2) results in anti-Stokes blue emission. The maximum upconversion quantum yield (Φ(UC) =17.4%) was obtained for the couple PdOEP/DTACl. In addition, the efficiency of the triplet-triplet energy transfer process was quantitatively studied by quenching experiments. Experimental results revealed that a highly effective acceptor for upconversion should combine high fluorescence quantum yields with efficient quenching of the sensitizer triplet., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A diode-pumped Yb-doped Gd(3)Al(0.5)Ga(4.5)O(12) mode-locked bulk laser based on chemically reduced graphene oxide (RGO) has been demonstrated for the first time to our best knowledge. Pulses with duration of 643 fs were produced at the central wavelength of 1041.1 nm. A maximum average output power of 0.8 W was obtained from the RGO mode-locked laser, corresponding to a slope efficiency of 20.1% and a peak power of 27.6 kW. The results indicate that RGO is suitable for obtaining high-power and high-efficiency ultrafast lasers.

For materials used in high-temperature thermoelectric power generation, the choices are still quite limited. Here we demonstrate the design and synthesis of a new class of complex Zintl compounds, Ca(1-x)RE(x)Ag(1-y)Sb (RE = La, Ce, Pr, Nd, Sm) (P63mc, No. 186, LiGaGe-type), which exhibit a high figure of merit in the high-temperature region. Compared with the parent structure that is based on CaAgSb (Pnma, No. 62, TiNiSi-type), an interesting structural relationship is established which suggests that important size and electronic effects govern the formation of these multinary phases. According to theoretical calculations, such a structural transformation from the orthorhombic TiNiSi-type to the hexagonal LiGaGe-type also corresponds to an obvious modification in the electronic band structure, which explains the observed significant enhancement of the related thermoelectric properties. For an optimized p-type material, Ca(0.84)Ce(0.16)Ag(0.87)Sb, a figure of merit of ~0.7 can be achieved at 1079 K, which is comparable to that of Yb14MnSb11 at the same temperature. In addition, due to the excellent thermal stability and high electrical conductivity, these materials are very promising candidates for high-temperature thermoelectric power generation.

Two new Zintl compounds A(10)LaCdSb(9) (A=Ca, Yb), namely, Ca(9.81(1))La(0.97(1))Cd(1.23(1))Sb(9) and Yb(9.78(1))La(0.97(1))Cd(1.24(1))Sb(9), have been designed and synthesized by applying the Zintl concept. Although both compounds are isoelectronic with their Ca(11)InSb(9) and Yb(11)InSb(9) analogues, they crystallize in a new structure type with the orthorhombic space group Ibam (No.72) and feature very complex anion structures, which are composed of unique [Cd(2)Sb(6)](12-) clusters, dumbbell-shaped [Sb(2)](4-) dimers, and isolated [Sb](3-) anions. For Yb(9.78(1))La(0.97(1))Cd(1.24(1))Sb(9), an extremely low lattice thermal conductivity of 0.29 W m(-1) K(-1) was observed at 875 K, which almost approaches the lowest reported limit of nonglassy or nonionically conducting bulk materials. According to thermogravimetric (TG) and differential scanning calorimetry (DSC) analyses, both compounds show very good thermal stability and no melting or phase transition processes were found below 1173 K. Although related thermoelectric property studies on Yb(9.78(1))La(0.97(1))Cd(1.24(1))Sb(9) only present a maximum ZT of 0.11 at 920 K, owing to its low Seebeck coefficients, these materials are still very promising for their high temperature stability and low thermal conductivity. Furthermore, as mixed cations exist with different charges, it makes this system very flexible in tuning the related electrical properties., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The previous structure determination of the title compound, dibarium tritelluridocadmate, was based on powder X-ray diffraction data [Wang & DiSalvo (1999 ▶). J. Solid State Chem.148, 464-467]. In the current redetermination from single-crystal X-ray data, all atoms were refined with anisotropic displacement parameters. The previous structure report is generally confirmed, but with some differences in bond lengths. Ba(2)CdTe(3) is isotypic with Ba(2)MX(3) (M = Mn, Cd; X = S, Se) and features (1) (∞)[CdTe(2/2)Te(2/1)](4-) chains of corner-sharing CdTe(4) tetra-hedra running parallel [010]. The two Ba(2+) cations are located between the chains, both within distorted monocapped trigonal-prismatic coordination polyhedra. All atoms in the structure are located on a mirror plane.

Fluorescent microspheres consisting of a conjugated phenylenevinylene 3B2B doped with a fluorenone derivative DSFO were prepared by a reprecipitation method. The DSFO-doped 3B2B microspheres (DMPs) exhibited significantly reduced fluorescence from 3B2B (donor) and strongly enhanced emission from DSFO (acceptor), which is highly sensitive to the concentration of metalloprotein.

Two new ternary Zintl phases, Sr(5)Sn(2)As(6) and Eu(5)Sn(2)As(6), have been synthesized, and their structures have been accurately determined through single-crystal X-ray diffraction. Both compounds crystallize in orthorhombic space group Pbam (No. 55, Z = 2) with cell parameters of a = 12.482(3)/12.281(5) Å, b = 14.137(3)/13.941(5) Å, and c = 4.2440(10)/4.2029(16) Å for Sr(5)Sn(2)As(6) (R1 = 0.0341; wR2 = 0.0628) and Eu(5)Sn(2)As(6) (R1 = 0.0324; wR2 = 0.0766), respectively. Their structure belongs to the Sr(5)Sn(2)P(6) type, which can be closely related to the Ca(5)Ga(2)As(6) type. Electronic band structure calculations based on the density functional theory reveal an interesting electronic effect in the structure formation of these two types of Zintl phases, which substantially affect their corresponding electronic band structure. Related studies on the thermal stability, magnetism, and thermoelectric properties of Eu(5)Sn(2)As(6) are presented as well.

A series of ternary Zintl phases, Ca(2)CdP(2), Ca(2)CdAs(2), Sr(2)CdAs(2), Ba(2)CdAs(2), and Eu(2)CdAs(2), have been synthesized through high temperature metal flux reactions, and their structures have been characterized by single-crystal X-ray diffraction. They belong to the Yb(2)CdSb(2) structure type and crystallize in the orthorhombic space group Cmc2(1) (No. 36, Z = 4) with cell dimensions of a = 4.2066(5), 4.3163(5), 4.4459(7), 4.5922(5), 4.4418(9) Å; b = 16.120(2), 16.5063(19), 16.904(3), 17.4047(18), 16.847(4) Å; c = 7.0639(9), 7.1418(8), 7.5885(11), 8.0526(8), 7.4985(16) Å for Ca(2)CdP(2) (R1 = 0.0152, wR2 = 0.0278), Ca(2)CdAs(2) (R1 = 0.0165, wR2 = 0.0290), Sr(2)CdAs(2) (R1 = 0.0238, wR2 = 0.0404), Ba(2)CdAs(2) (R1 = 0.0184, wR2 = 0.0361), and Eu(2)CdAs(2) (R1 = 0.0203, wR2 = 0.0404), respectively. Among these, Ca(2)CdAs(2) was found to form with another closely related structure, depending on the experimental conditions--monoclinic space group Cm (No. 8, Z = 10) with lattice constants a = 21.5152(3) Å, b = 4.30050(10) Å, c = 14.3761(2) Å and β = 110.0170(10)° (R1 = 0.0461, wR2 = 0.0747). UV/vis optical absorption spectra for both forms of Ca(2)CdAs(2) show band gaps on the order of 1.0 eV, suggesting semiconducting properties, which have also been confirmed through electronic band structure calculations based on the density-functional theory. Results from differential scanning calorimetry measurements probing the thermal stability and phase transitions in the two Ca(2)CdAs(2) polymorphs are discussed. Magnetic susceptibility measurements for Eu(2)CdAs(2), indicating divalent Eu(2+) cations, are presented as well.

Two new chromophores with carbazole as molecular focal point bearing either one o-pyridine-benzothiadiazole unit or two o-pyridine-benzothiadiazole units at the periphery respectively, named as 2,8-(o-pyridine-benzothiadiazole)-N-ethyl-carbazole (CPTZ1) and 2,8-bis(o-pyridine-benzothiadiazole)-N-ethyl-carbazole (CPTZ2), were synthesized and characterized by IR spectra, 1H NMR spectra and MS. The influence of proton upon one-photon and two-photon fluorescence about these two compounds was discussed. Stern-Volmer equation gives that the S-V constants (k(SV)(1P)) of one-photon fluorescence (1PF) of CPTZ1 and CPTZ2 are 0.04 and 0.10 L mol(-1), respectively; while the k(SV)(2P) of two-photon fluorescence (2PF) of CPTZ1 and CPTZ2 are 0.20 and 0.22 L mol(-1), respectively. Obviously, two-photon (2P) fluorescence detection presented more sensitivity than one-photon (1P) fluorescence response, which exhibits the potential application of two-photon sensor in PH detection.

Research on structure-property relationships in distyrylarylene derivatives is far behind their wide applications in optoelectronic devices due to the absence of crystal structure information. Herein, the single crystals of 4,4'-bis(2-thienylvinyl)biphenyl (1) and 4,4'-bis(2-thieno[3,2-b]thienylvinyl)biphenyl (2) were successfully grown by the vapor transport method. Both molecules adopt the typical herringbone packing motif. However, the intermolecular C-H⋅⋅⋅π interaction in compound 2 is much stronger than that in compound 1. The correlations of interchain interaction with film morphology, optical and electronic properties were studied. Compound 2 formed higher crystalline films with (001) and (111) orientations. The organic field-effect transistor properties of both materials were investigated. Compound 2 showed better performance with a hole mobility higher than 0.01 cm(2)  V(-1)  s(-1) and an on/off current ratio over 10(6) . These results reveal that the intensity of C-H⋅⋅⋅π interactions can exert dramatic influences on the optical and electronic properties of distyrylarylene-based materials., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In the title compound, C(13)H(10)S(2)Te, the dibenzothio-phene moiety is almost planar, the maximum atomic deviation being 0.055 (5) Å. The two Te-C bonds are nearly perpen-dicular to each other with a C-Te-C bond angle of 93.0 (2)°. An inter-molecular C-H⋯π inter-action is present between the methyl-ene group and thio-phene ring.

The performance of a diode-end-pumped passively Q-switched dual-wavelength Nd:GGG laser operating at 932.9 and 936.5 nm with V(3+):YAG as the saturable absorber was demonstrated for the first time to the best of our knowledge. The maximum dual-wavelength average output power of 150 mW was achieved with a T = 2% output coupler under the absorbed pump power of 2.55 W, corresponding to the optical-to-optical conversion and slope efficiency of 5.9% and 8.0%, respectively. The minimum pulse width was 395 ns with the pulse repetition frequency of 140 kHz, which was attained with a T = 5% output coupler under the absorbed pump power of 2.55 W.

Four new D-pi-D (or D-pi-D-pi-D) complexes 9-ethyl-3-E-((1-ferrocenyl)vinyl)-carbazole (1), 9-ethyl-3,6-E,E-((1,1-diferrocenyl)vinyl)- carbazole(2), 10-ethyl-3-E-((1-ferrocenyl)vinyl)-phenothiazine (3), 10-ethyl- 3,7-E,E- ((1,1-diferrocenyl)vinyl)-phenothiazine (4), have been obtained by solid-phase Wittig reactions and fully characterized. The four complexes were treated with iodine leading to four corresponding [D-pi-A](+) I(3)(-) ferrocenium triiodides (+)I(3)(-) (5), (+)I(3)(-) (6), (+)I(3)(-) (7) and 4(+)I(3)(-) (8), respectively. The results of single crystal X-ray diffraction analysis show that and display better coplanarity between the Fc and carbazole subunits than that between the phenothiazine and ferrocene moieties, which leads to a better pi-electron delocalization. Both the poor pi-electron in [D-pi-A](+) ferroceniums and the heavy iodine atom have a negative effect on the electrochemical properties. The complexes 1-8 undergo multi-step redox processes and show lower oxidation potentials compared with those of ferrocene. Density functional theory (DFT) calculations are performed and the experimental redox properties of the complexes are studied. The eight complexes show MLCT and pi-pi transitions in the UV-visible range in solution, which have been verified by TD-DFT theoretical calculations. In all cases the highest-lying occupied molecular orbitals of the eight complexes are mainly localized on the Fe d orbitals and show a greater Fe proportion than that of alkyl in the complexes, whereas the LUMOs and LUMO+1 are mainly from the pi orbitals of the conjugated vinyl carbazole or phenothiazine unit.

The synthesis, structure, and single- and two-photon spectroscopic properties of a series of pyrimidine-based (bent-shaped) molecules are reported. All these stable heterocyclic compounds are fully characterized, and exhibit intense single- and two-photon excited fluorescence (SPEF and TPEF) over a wide spectral range from blue to red, with the spectral peak position of the SPEF being basically the same as that of the TPEF. The well-conjugated pi-systems, observed from the crystal structure, indicate the charge transfer feature of the ground state. Meanwhile, the theoretical and experimental studies indicate that the charge transfer from donor to acceptor is greatly enhanced in the excited states and the different substituted donor groups on the pyrimidine have a large effect on the optical and electrochemical properties. Based on typical structure data and comprehensive spectral data, the following structure-property relationships can be determined: for such bent-shaped chromophores, the absorption and the fluorescence wavelength maximum of the SPEF and TPEF, and two-photon absorption cross sections show a similar trend with increasing electron-donating strength of the corresponding terminal group and the number of branches, while the average bond lengths of the pi-linkage and HOMO-LUMO energy levels show an inverse trend. Experimental data and theoretical calculation provide a coherent picture. With these findings, bent-shaped quadrupolar chromophores combining peak TPA cross sections (up to 2280 GM), broad TPA bands throughout the whole 700-900 nm range, and high fluorescence quantum yields could, thus, be obtained. Such compounds are of particular interest for TPEF microscopy, as well as optical data storage in the visible and NIR regions. A data recording experiment proved the potential application of these materials.

In the title compound, C(31)H(27)N(3), the cyclo-hexene ring has an envelope configuration. In the crystal structure, there is an 34 Å(3) void around the inversion center, but the low electron density (0.13 e Å(-3)) in the difference Fourier map suggests no solvent mol-ecule occupying this void. No hydrogen bonding is found in the crystal structure.

By combining a large pi-conjugated bidentate ligand L: 3,6-dipyrazole-N-ethylcarbazole with HgI(2), an extraordinary supramolecular coordination polymer, [Hg(4)L(2)I(8)](infinity), has been prepared. The crystal structures of the ligand and its coordination polymer were determined by X-ray crystallography, which shows three varied coordination modes especially the rare asymmetric quadruply bridged trinuclear moieties in [Hg(4)L(2)I(8)](infinity). Density functional theory (DFT) calculations (ADF) performed on model dimers show the roles of covalent and noncovalent interactions in establishing the three-dimensional architecture.

Quenching effect of the photoluminescence of 1,2,4,5-tetrakis(4-pyridylvinyl)benzene in the presence of CdS colloids stabilized by inverse micelles was observed. The observed regularities of luminescence quenching by the quenchers of different size were studied. An increase in the two-photon absorption cross section (6.5 times higher) and in the two-photon-induced fluorescence intensity was observed for the composite solution when pumped by 740-nm laser irradiation. The results are in accord with theoretical prediction of enhancement of third-order optical nonlinearity of quantum-confined semiconductor.

Multibranched pi-conjugated materials and hyperbranched polymers have received considerable interest in both academic research and industrial applications because of their unusual molecular structures and properties. In this communication, we provide an efficient approach to synthesize two novel pi-conjugated multibranch compounds, which have good solubility and are nanosize (about 5 nm). The double bonds of the multibranch compounds are synthesized using solvent-free Wittig-Horner-Emmons reactions. The reaction conditions are simple and mild. Their optical properties are discussed too.