Direct Measurement of Dissolved Gas Using a Tapered Single-Mode Silica Fiber.

Dissolved gases in the aquatic environment are critical to understanding the population of aquatic organisms and the ocean. Currently, laser absorption techniques based on membrane separation technology have made great strides in dissolved gas detection. However, the prolonged water-gas separation time of permeable membranes remains a key obstacle to the efficiency of dissolved gas analysis. To mitigate these limitations, we demonstrated direct measurement of dissolved gas using the evanescent-wave absorption spectroscopy of a tapered silica micro-fiber. It enhanced the analysis efficiency of dissolved gases without water-gas separation or sample preparation. The feasibility of this sensor for direct measurement of dissolved gases was verified by taking the detection of dissolved ammonia as an example. With a sensing length of 5 mm and a consumption of ~50 µL, this sensor achieves a system response time of ~11 min and a minimum detection limit (MDL) of 0.015%. Possible strategies are discussed for further performance improvement in in-situ applications requiring fast and highly sensitive dissolved gas sensing.

Boosting the Electrochemical Performance of Primary and Secondary Lithium Batteries with Mn-Doped All-Fluoride Cathodes.

Transition metal fluorides are potentially high specific energy cathode materials of next-generation lithium batteries, and strategies to address their low conductivity typically involve a large amount of carbon coating, which reduces the specific energy of the electrode. In this study, MnyFe1-yF3@CFx was generated by the all-fluoride strategy, converting most of the carbon in MnyFe1-yF3@C into electrochemical active CFx through a controllable NF3 gas phase fluorination method, while still retaining a tightly bound graphite layer to provide initial conductivity, which greatly improved the energy density of the composite. This synergistic effect of nonfluorinated residual carbon (∼11%) and Mn doping ensures the electrochemical kinetics of the composite. The loading mass of the active substance had been increased to 86%. The theoretical and actual discharge capacity of MnyFe1-yF3@CFx composite was up to 765 mAh g-1 (pure FeF3 is 712 mAh g-1) and 728 mAh g-1, respectively. The discharge capacity at the high-voltage (3.0 V) platform was more than three times higher than that of the non-Mn-doped composite (FeF3@CFx).

Short communication: possible mechanism for inhibiting the formation of polymers originated from 5-hydroxymethyl-2-furaldehyde by sulfite groups in the dairy thermal process.

5-Hydroxymethyl-2-furaldehyde can undergo polymerization to form high-molecular weight molecules via the Maillard reaction during dairy thermal treatment. In this study, the effect of sulfite group on polymer formation, especially in inhibiting the formation of high-molecular weight polymers has been described. Results showed that the sulfite group significantly inhibited the increase of polymer molecular weight via prevention of the polymerization of 5-hydroxymethyl-2-furaldehyde. The formation of an intermolecular dimer based on the glucose molecule through Schiff base cyclization can lead to a competitive reaction with 1,2-enolization to reduce 5-hydroxymethyl-2-furaldehyde formation, which might be another factor in reducing the formation of high-molecular weight polymers.

Microfluidic static droplet generated quantum dot arrays as color conversion layers for full-color micro-LED displays.

This paper presents an easy and intact process based on microfluidics static droplet array (SDA) technology to fabricate quantum dot (QD) arrays for full-color micro-LED displays. A minimal sub-pixel size of 20 µm was achieved, and the fluorescence-converted red and green arrays provide good light uniformity of 98.58% and 98.72%, respectively.

Micropore filling fabrication of high resolution patterned PQDs with a pixel size less than 5 µm.

PQDs are promising color converters for micro-LED applications. Here we report the micropore filling fabrication of high resolution patterned PQDs with a pixel size of 2 µm using a template with SU8 micropores.

Flexible Quantum-Dot Color-Conversion Layer Based on Microfluidics for Full-Color Micro-LEDs.

In this article, red and green perovskite quantum dots are incorporated into the pixels of a flexible color-conversion layer assembly using microfluidics. The flexible color-conversion layer is then integrated with a blue micro-LED to realize a full-color display with a pixel pitch of 200 µm. Perovskite quantum dots feature a high quantum yield, a tunable wavelength, and high stability. The flexible color-conversion layer using perovskite quantum dots shows good luminous and display performance under different bending conditions; is easy to manufacture, economical, and applicable; and has important potential applications in the development of flexible micro-displays.

Poly[diaqua-bis-(µ(3)-1H-imidazole-4,5-dicarboxyl-ato)(µ(2)-sulfato)-diytterbium(III)].

In the title compound, [Yb(2)(C(5)H(2)N(2)O(4))(2)(SO(4))(H(2)O)(2)](n), the Yb(III) ion is eight-coordinated by four O atoms and one N atom from three imidazole-4,5-dicarboxyl-ate ligands, two O atoms from one SO(4) (2-) anion (site symmetry 2), as well as one O atom of a water mol-ecule, giving a bicapped trigonal-prismatic coordination geometry. The metal coordination units are connected by bridging imidazole-4,5-dicarboxyl-ate and sulfate ligands, generating a heterometallic layer. The layers are stacked along the a axis via N-H⋯O, O-H⋯O, and C-H⋯O hydrogen-bonding inter-actions, generating a three-dimensional framework.

Poly[[tetra-aqua-bis-(µ(3)-imidazole-4,5-dicarboxyl-ato)tetra-kis-(µ(2)-imidazole-4,5-dicarboxyl-ato)tricobalt(II)dilutetium(III)] dihydrate].

In the title compound, {[Co(3)Lu(2)(C(5)H(2)N(2)O(4))(6)(H(2)O)(4)]·2H(2)O}(n), the Lu(III) ions are seven-coordinated in a monocapped trigonal prismatic coordination geometry by six O atoms from three imidazole-4,5-dicarboxyl-ate ligands and one water O atom. The Co(II) ions are six-coordinated in a slightly distorted octa-hedral geometry and exhibit two types of coordination environments. One Co(II) ion, located on an inversion center, is coordinated by two water O atoms as well as two O atoms and two N atoms from two imidazole-4,5-dicarboxyl-ate ligands. The other Co(II) ion is bonded to four O atoms and two N atoms from four imidazole-4,5-dicarboxyl-ate ligands. These metal coordination units are connected by bridging imidazole-4,5-dicarboxyl-ate ligands, generating a three-dimensional network. The crystal structure is further stabilized by N-H⋯O, O-H⋯O, and C-H⋯O hydrogen-bonding inter-actions between the water mol-ecules and the imidazole-4,5-dicarboxyl-ate ligands.

Poly[[tetra-aqua-(µ(4)-imidazole-4,5-dicarboxyl-ato)(µ(3)-imidazole-4,5-dicarboxyl-ato)-µ(3)-sulfato-µ(2)-sulfato-cobalt(II)digadolinium(III)] monohydrate].

The asymmetric unit of the title compound, {[CoGd(2)(C(5)H(2)N(2)O(4))(2)(SO(4))(2)(H(2)O)(4)]·H(2)O}(n), contains one Co(II) ion, two Gd(III) ions, two imidazole-4,5-dicarboxyl-ate ligands, two SO(4) (2-) anions, four coordinated water mol-ecules and one uncoordinated water mol-ecule. The Co(II) ion is six-coordinated by two O atoms from two coordinated water mol-ecules, as well as two O atoms and two N atoms from two imidazole-4,5-dicarboxyl-ate ligands, giving a slightly distorted octa-hedral geometry. Both Gd(III) ions are eight-coordinated in a distorted bicapped trigonal-prismatic geometry. One Gd(III) ion is coordinated by four O atoms from two imidazole-4,5-dicarboxyl-ate ligands, three O atoms from three SO(4) (2-) anions and a water O atom; the other Gd(III) ion is bonded to five O atoms from three imidazole-4,5-dicarboxyl-ate ligands, two O atoms from two SO(4) (2-) anions as well as a water O atom. These metal coordination units are connected by bridging imidazole-4,5-dicarboxyl-ate and sulfate ligands, generating a heterometallic layer parallel to the ac plane. The layers are stacked along the b axis via N-H⋯O, O-H⋯O, and C-H⋯O hydrogen-bonding inter-actions, generating a three-dimensional framework.

Poly[tetra-deca-aqua-tetra-kis-(µ(3)-1H-imidazole-4,5-dicarboxyl-ato)tetra-µ(3)-sulfato-cobalt(II)hexa-gadolinium(III)].

The asymmetric unit of the title compound, [CoGd(6)(C(5)H(2)N(2)O(4))(4)(SO(4))(6)(H(2)O)(14)](n), contains a Co(II) ion (site symmetry [Formula: see text]), three Gd(III) ions, two imidazole-4,5-dicarboxyl-ate ligands, three SO(4) (2-) anions, and seven coordinated water mol-ecules. The Co(II) ion is six-coordinated by two O atoms from water mol-ecules, two O atoms and two N atoms from two imidazole-4,5-dicarboxyl-ate ligands, giving a slightly distorted octa-hedral geometry. The Gd(III) ions exhibit three types of coordination environments. One Gd ion is eight-coordinated in a bicapped trigonal-prismatic geometry by four O atoms from two imidazole-4,5-dicarboxyl-ate ligands, two O atoms from two SO(4) (2-) anions and two coordinated water mol-ecules. The other Gd ions are nine-coordinated in a tricapped trigonal-prismatic geometry; one of these Gd ions is bonded to four O atoms from two imidazole-4,5-dicarboxyl-ate ligands, three O atoms from three SO(4) (2-) anions and two water O atoms and the other Gd ion is coordinated by one O atom and one N atom from one imidazole-4, 5-dicarboxyl-ate ligand, five O atoms from three SO(4) (2-) anions as well as two coordinated water mol-ecules. These metal coordination units are connected by bridging imidazole-4,5-dicarboxyl-ate and sulfate ligands, generating a three-dimensional network. The crystal structure is further stabilized by N-H⋯O, O-H⋯O, and C-H⋯O hydrogen-bonding inter-actions between water mol-ecules, SO(4) (2-) anions, and imidazole-4,5-dicarboxyl-ate ligands.

Poly[[tetra-aqua-bis-(µ(3)-1H-imidazole-4,5-dicarboxyl-ato)tetra-kis-(µ(2)-1H-imidazole-4,5-dicarboxyl-ato)tricobalt(II)diytterbium(III)] dihydrate].

The asymmetric unit of the title compound, {[Co(3)Yb(2)(C(5)H(2)N(2)O(4))(6)(H(2)O)(4)]·2H(2)O}(n), contains one Yb(III) ion, two Co(II) ions (one situated on an inversion centre), three imidazole-4,5-dicarboxyl-ate ligands, two coordinated water mol-ecules and one uncoordinated water mol-ecule. The Yb(III) ion is seven-coordinated, in a monocapped trigonal prismatic coordination geometry, by six O atoms from three imidazole-4,5-dicarboxyl-ate ligands and one water O atom. Both Co(II) ions are six-coordinated in a slightly distorted octa-hedral geometry. The Co(II) ion that is located on an inversion center is coordinated by two O atoms from two water mol-ecules, as well as two O atoms and two N atoms from two imidazole-4,5-dicarboxyl-ate ligands. The second Co(II) ion is bonded to four O atoms and two N atoms from four imidazole-4,5-dicarboxyl-ate ligands. These metal coordination units are connected by bridging imidazole-4,5-dicarboxyl-ate ligands, generating a three-dimensional network. The crystal structure is further stabilized by N-H⋯O, O-H⋯O and C-H⋯O hydrogen-bonding inter-actions involving the water mol-ecules and the imidazole-4,5-dicarboxyl-ate ligands.

Poly[[(µ(2)-acetato-κO,O':O')aqua-bis-(µ(3)-isonicotinato-κO:O':N)samarium(III)silver(I)] perchlorate].

The title compound, {[AgSm(C(6)H(4)NO(2))(2)(CH(3)CO(2))(H(2)O)]ClO(4)}(n), is a three-dimensional heterobimetallic complex constructed from a repeating dimeric unit. Only half of the dimeric moiety is found in the asymmetric unit; the unit cell is completed by crystallographic inversion symmetry. The Sm(III) ion is eight-coordinated by four O atoms of four different isonicotinate ligands, three O atoms of two different acetate ligands, and one O atom of a water mol-ecule. The two-coordinate Ag(I) ion is bonded to two N atoms of two different isonicotinate anions, thereby connecting the disamarium units. In addition, the isonicotinate ligands also act as bridging ligands, generating a three-dimensional network. The coordinated water mol-ecules link the carboxyl-ate group and acetate ligands by O-H⋯O hydrogen bonding. Another O-H⋯O hydrogen bond is observed in the crystal structure. The perchlorate ion is disordered over two sites with site-occupancy factors of 0.560 (11) and 0.440 (11), whereas the methyl group of the acetate ligand is disordered over two sites with site-occupancy factors of 0.53 (5) and 0.47 (5).

Poly[tetra-deca-aqua-tetra-kis-(µ(3)-imidazole-4,5-dicarboxyl-ato)hexa-µ(3)-sulfato-cobalt(II)hexa-samarium(III)].

In the title three-dimensional compound, [CoSm(6)(C(5)H(2)N(2)O(4))(4)(SO(4))(6)(H(2)O)(14)](n), the Co(II) ion is six-coordinated with two O atoms and two N atoms from two imidazole-4,5-dicarboxyl-ate ligands and two coordinated water mol-ecules, giving a slightly distorted octa-hedral geometry. One Sm(III) ion is eight-coordinated in a bicapped trigonal-prismatic coordination geometry by four O atoms from two imidazole-4,5-dicarboxyl-ate ligands, two O atoms from two SO(4) (2-) anions and two coordinated water mol-ecules. The other two Sm(III) ions are nine-coordinated in a tricapped trigonal-prismatic coordination geometry; one of these Sm(III) ions is bonded to four O atoms from two imidazole-4,5-dicarboxyl-ate ligands, three O atoms from three SO(4) (2-) anions and two water O atoms, and the other Sm(III) ion is coordinated by one O atom and one N atom from one imidazole-4,5-dicarboxyl-ate ligand, five O atoms from three SO(4) (2-) anions, as well as two coordinated water mol-ecules. The crystal structure is further stabilized by N-H⋯O, O-H⋯O, and C-H⋯O hydrogen-bonding inter-actions.

Ethyl-enediammonium bis-(3,4-dihy-droxy-benzoate) monohydrate.

In the title compound, C(2)H(10)N(2) (2+)·2C(7)H(5)O(4) (-)·H(2)O, the cation lies on a centre of symmetry. The crystal structure is stabilized by various inter-molecular O-H⋯O and N-H⋯O hydrogen bonds, and by weak π-π stacking inter-actions with centroid-centroid distances between symmetry-related benzene rings ranging from 3.5249 (13) to 3.7566 (14) Å.

Ammonium (E)-3-(4-hy-droxy-3-meth-oxy-phen-yl)prop-2-enoate monohydrate.

In structure of the title compound ammonium ferulate monohydrate, NH(4) (+)·C(10)H(9)O(4) (-)·H(2)O, O-H⋯O and N-H⋯O hydrogen bonds link the ammonium cations, ferulate anions and water mol-ecules into a three-dimensional array. The ferulate anion is approximately planar, with a maximum deviation of 0.307 (2) Å.

Anilinium 3-(4-hy-droxy-3-meth-oxy-phenyl)prop-2-enoate.

The structure of the title salt, C(6)H(8)N(+)·C(10)H(9)O(4) (-), is stabilized by N-H⋯O and O-H⋯O hydrogen bonding between 3-(4-hy-droxy-3-meth-oxy-phen-yl)prop-2-enoate anions and anilinium cations, which links the components into a two-dimensional array.

Triethyl-ammonium 3,4-dihy-droxy-benzoate.

In the title compound, C(6)H(16)N(+)·C(7)H(5)O(4) (-), the hy-droxy groups of the 3,4-dihy-droxy-benzoate anion form O-H⋯O hydrogen bonds to the carboxyl-ate groups of two adjacent anions, generating layers propagating in the ac plane. The triethyl-ammonium cations lie between these layers, forming N-H⋯O hydrogen bonds to the carboxyl-ate groups of the anions. The structure is consolidated by weak inter-molecular C-H⋯O inter-actions.

Triethyl-ammonium 3,4-dihy-droxy-benzoate monohydrate.

In the structure of the title compound, C(6)H(16)N(+)·C(7)H(5)O(4) (-)·H(2)O, O-H⋯O and N-H⋯O hydrogen bonds link the components into a three-dimensional array. The 3,4-dihy-droxy-benzoate anion is approximately planar, with a maximum deviation of 0.083 (2) Å.

3,4-Dihy-droxy-benzoic acid pyridine monosolvate.

The asymmetric unit of the title compound, C(7)H(6)O(4)·C(5)H(5)N, consists of one 3,4-dihy-droxy-benzoic acid and one pyridine mol-ecule, both located on general positions. The 3,4-dihy-droxy-benzoic acid mol-ecules are arranged in layers and are connected by inter-molecular O-H⋯O hydrogen bonding, forming channels along the a axis in which the pyridine mol-ecules are located. The pyridine and the acid mol-ecules are additionally linked by strong O-H⋯N hydrogen bonding and by weak π-π stacking inter-actions with centroid-centroid distances between the pyridine rings of 3.727 (2) Å.

Erratum: Poly[[di-µ(3)-nicotinato-µ(3)-oxalato-samarium(III)silver(I)] dihydrate]. Corrigendum.

The title of the paper by Zhu, Zhao & Yu [Acta Cryst. (2009), E65, m1105] is corrected.[This corrects the article DOI: 10.1107/S1600536809032115.].