Bis(formato-κO)bis­[1-(pyridin-2-yl)ethanone oxime-κ2 N,N′]nickel(II)

In the title compound, [Ni(HCOO)2(C7H8N2O)2], the Ni atom is six-coordinated by four N atoms from two oxime ligands and by two O atoms from two formate ions in a distorted octa­hedral geometry, with the oxime-N atoms mutually trans. The mol­ecular conformation is stabilized by intra­molecular O—H⋯O hydrogen bonds

Bis[2-(pyridin-2-yl)ethanol-κ2 N,O]bis­(thio­cyanato-κN)nickel(II)

In the title complex, [Ni(NCS)2(C7H9NO)2], the NiII atom is in a distorted octa­hedral coordination environment defined by two N atoms of the two thio­cyanate ions and by the N and O atoms of the two chelating 2-(pyridin-2-yl)ethanol ligands. The complex mol­ecule is located around a crystallographic inversion center. In the crystal, mol­ecules are connected into a two-dimensional polymeric structure parallel to (100) by O—H⋯S hydrogen bonds

Chlorido[1-(pyridin-2-yl)ethanone oximato-κ2 N,N′][1-(2-pyrid­yl)ethanone oxime-κ2 N,N′]copper(II) trihydrate

In the title compound, [Cu(C7H7N2O)Cl(C7H8N2O)]·3H2O, the metal ion is five-coordinated by the N atoms from the 1-(pyridin-2-yl)ethanone oximate and 1-(pyridin-2-yl)ethanone oxime ligands and by the chloride anion in a distorted square-pyramidal geometry. The distortion parameter is 0.192. The two organic ligands are linked by an intra­molecular O—H⋯O hydrogen bond. In the crystal, mol­ecules are linked by O—H⋯O and O—H⋯Cl hydrogen bonds. The title compound is the hydrated form of a previously reported structure [Wu & Wu (2008 ▶). Acta Cryst. E64, m828]. There are only slight variations in the mol­ecular geometries of the two compounds

A Scaling Scheme for DCT Precoded Optical Intensity-Modulated Direct Detection Systems

A scaling technique is employed to improve the performance of a Discrete Cosine Transform (DCT) precoded optical intensitymodulated direct detection (IM/DD) OFDM system, which fully exploits the dynamic range of a digital-to-analog converter (DAC). The theoretical analysis shows that the proposed scaling scheme can improve the BER performance of DCT precoded and scaled OFDM systems. The experiment results also show that the proposed scheme significantly improves the BER performance without changing the receiver structure. The measured received sensitivity at a BER of 10 −3 for a 4 G samples/s (2.7 Gbits/s) DCT precoded and scaled OFDM signal and after 100 km standard single-mode fiber (SMF) transmission has been improved by 3 and 1.3 dB when compared with the original OFDM system and conventional DCT precoded OFDM system, respectively

Tunable Fluorescence-Responsive Double Hydrophilic Block Polymers Induced by the Formation of Pseudopolyrotaxanes with Cucurbit[7]Uril

There is an urgent need for new strategies that allow the simultaneous detection and control of drug delivery. By making use of supramolecular host-guest interactions, a kind of pseudopolyrotaxanes, as a visualizable nanoscale drug carrier has been constructed by self-assembly of cucurbit[7]uril (CB[7]) with methoxy poly(ethylene glycol)-block-quaternized poly(4-vinyl pyridine) (mPEG-b-QP4VP) using 4-(chloromethyl)benzonitrile. Simple addition of CB[7] into an aqueous solution of mPEG-b-QP4VP resulted in noncovalent attachment of CB[7] to 4-cyanobenzyl-containing polymers, transforming the nonemissive mPEG-b-QP4VP micelles into highly fluorescent micelles. These pseudopolyrotaxanes micelles exhibited remarkable supramolecular assembly-induced emission enhancement and excellent biocompatibility, showing great potential for bioimaging applications. In addition, the efficient cellular uptake of the developed pseudopolyrotaxanes micelles loaded with the anticancer drug doxorubicin was a promising platform for simultaneous cell imaging and drug delivery, thereby widening their application in cancer theranostics

New lanthanide-based complexes constructed from cucurbit[6]uril: Synthesis, structures and properties

<p>Three lanthanide-based complexes, {Gd₂(H₂O)₁₀(CB[6])₂}·CB[6]·6Cl·12H₂O (<b>1</b>), {[Gd₂(H₂O)₈CB[6]₂]·(CuCl₄)·4Cl·46H₂O}_n (<b>2</b>), and {Dy₂(NO₃)₂(H₂O)₁₀(CB[6])}·4NO₃·14H₂O (<b>3</b>) (CB[6] = cucurbit[6]uril), were prepared with cucurbit[6]uril (CB[6]). These complexes were characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR spectroscopy, UV–Vis spectroscopy, thermogravimetric analysis and magnetization measurements. Crystallographic results showed that <b>1</b> and <b>3</b> are dinuclear and crystallize in the triclinic space group <i>P</i>ī, whereas <b>2</b> is a 1-D zigzag supramolecular chain that crystallizes in the monoclinic system in <i>C</i>2/<i>c</i>. The results indicated that temperature has a big effect on the supramolecular assemblies and a different structure inducer also leads to the formation of different coordination polymers. Frequency dependence in the ac susceptibility signals was observed in <b>3</b>.</p