Luminescent Cadmium Research Articles

Hydrothermal syntheses, structures and characterizations of two luminescent cadmium(II) complexes with p-xylenediphosphonic acid and N-donor ligands

Two novel cadmium diphosphonates [Cd(cis-H4BDPP)(2,2′-bipy)2]·(trans-H2BDPP)]n (1) and [Cd(trans-H2BDPP)(phen)]n (2) (H4BDPP=p-xylenediphosphonic acid, phen=1,10-phenanthroline, 2,2′-bipy=2,2′-bipyridine) were hydrothermally synthesized from p-xylenediphosphonic acid and CdSO4·3H2O with phen or 2,2′-bipy as second ligand components and characterized by means of elemental analyses, IR, TG analysis, luminescence spectroscopy and single crystal X-ray diffraction. Compound 1 consists of a novel one-dimensional (1D) sinusoidal [Cd(cis-H4BDPP)(2,2′-bipy)2] chains and trans-H2BDPP anions. Compound 2 possesses a three-dimensional architecture built from double zigzag –Cd–O–P–O–Cd– chains pillared by trans-p-xylylenediphosphonate ligands from four different directions. There are hexagonal channels running along the c-axis and the coordinated phen ligands suspend in the hexagonal channels. The results indicate that p-xylenediphosphonic acid can adopt varied coordination modes and conformations in the formation of the complexes and the influence of the N-donor ligands on the structure of the complexes is discussed.

Luminescent cadmium and zinc diphenate coordination polymers containing pyridyl-piperazine type ligands: Grids, diamondoid lattices, and a rare 4-connected net

Hydrothermal synthesis has afforded five d10 configuration divalent metal diphenate coordination polymers containing pyridyl-piperazine type ligands, which were structurally characterized by single-crystal X-ray diffraction. {[Cd(diphenate)(3-bpmp)(H2O)]·0.5H2O}n (1, 3-bpmp=bis(3-pyridylmethyl)piperazine) has a double layer topology. Its perchlorate-containing analog {[Cd3(diphenate)4(H23-bpmp)(H3-bpmp)(H2O)2](ClO4)·7H2O}n (2) possesses a very rare 4-connected 658 dmp topology based on anionic trinuclear nodes. {[Cd(diphenate)(4-bpfp)]·H2O}n (3, 4-bpfp=bis(4-pyridylformyl)piperazine) manifests a non-interpenetrated diamondoid lattice, while the related compound [Cd(diphenate)(4-bpmp)(H2O)]n (4, 4-bpmp=bis(4-pyridylmethyl)piperazine) has a simple (4,4) grid topology. {[Zn(diphenate)(4-bpmp)]·0.5H2O}n (5) displays a 2-fold interpenetrated diamondoid lattice. Luminescent properties of these materials are also reported.

Simple Non-aqueous Fabrication Route for Oleic Acid Capped Luminescent Cadmium Sulphide Quantum Dots at Relatively Low Temperature

In this communication, we report a simplistic non-aqueous fabrication route for oleic-acid capped luminescent cadmium sulphide quantum dots at low temperature. The resulting quantum dots, obtained without using any complicated reagents, are cubic in phase, monodispersed and have excellent optical properties. The simplicity of this fabrication route is also promising to develop other oleic acid-capped metal sulphide quantum dots at relatively low temperature.

Construction of a 3D luminescent cadmium(II) network with an unusual deprotonated 1,3-imidazolidine-2-thione ligand

Abstract A novel three-dimensional (3D) polymer [Cd(SC3H5N2)2]n (SC3H5N2 = deprotonated 1,3-imidazolidine-2-thione) (1) was synthesized. The deprotonated 1,3-imidazolidine-2-thione ligand has been found at cadmium for the first time. The single-crystal X-ray diffraction shows that the deprotonated 1,3-imidazolidine-2-thione ligand contributes greatly to the formation of the 3D framework and the helical structure. Compound 1 exhibits blue fluorescence at 494 nm in the solid state upon excitation at 372 nm.

Dual-ligand approach to the synthesis of new luminescent cadmium(II) coordination polymers with one- and two-dimensional homochiral structures

Two new homochiral cadmium(II) coordination polymers, Cd 2(bipy) 2(H 2O) 2 (cam) 2 ( 1) and Cd 2(phen) 2(cam) 2·eg ( 2), where bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline, H 2cam = (1R, 3S)-(+)-camphoric acid, and eg = ethylene glycol, have been synthesized by a dual-ligand approach. Compound 1 possesses a chain-like architecture and compound 2 has a layered structure with a (4,4) grid topology. Both compounds crystallize in the space group C2 and exhibit intense photoluminescence upon photoexcitation at 280 and 300 nm, respectively.

Effect of pendant arm length and nitrogen donor disposition on the topology of luminescent cadmium phenylenedicarboxylate coordination polymers with bis(pyridylmethyl)piperazine co-ligands

Hydrothermal synthesis has afforded divalent cadmium coordination polymers containing bis(pyridylmethyl)piperazine (bpmp) tethers and either phenylenediacetate (phda) or phenylenedipropionate (phdp) ligands. {[Cd(1,4-phda)(4-bpmp)]·1.5H2O}n (1) displays a (4,4)-grid layered structure based on 4-connected {Cd2O2} dimeric units. Extension of the pendant arms generated {[Cd(1,4-phdp)(H4-bpmp)](ClO4)·3.5H2O}n (2, phdp = phenylenedipropionate), which possesses a rare (3,6) 2D trigonal lattice based on 6-connected {Cd2O2} dimers. Changing the nitrogen donor atom disposition by using 3-bpmp as the nitrogen co-ligand yielded [Cd(1,4-phdp)(3-bpmp)(H2O)]n (3), which crystallizes in a 3-fold interpenetrated achiral diamondoid lattice. [Cd(1,3-phda)(4-bpmp)]n (4) adopts a very similar structure to that of 1. Complexes 1–4 undergo blue-violet luminescence upon exposure to ultraviolet radiation.

Counteranion and donor disposition effects on the topology of luminescent cadmium coordination polymers incorporating bis(pyridylmethyl)piperazine isomers

Four divalent cadmium coordination polymers, incorporating isomers of the hydrogen bonding capable diimine bis(pyridylmethyl)piperazine, have been prepared via solvent diffusion methods. Single crystal X-ray diffraction studies revealed both nitrogen donor disposition and anion dependence on dimensionality and topology. {[Cd(H 2O) 4(4-bpmp)](ClO 4) 2 · (4-bpmp) · 4H 2O} n ( 1, 4-bpmp = bis(4-pyridylmethyl)piperazine) exhibits cationic 1-D [ Cd ( H 2 O ) 4 ( 4 -bpmp ) ] n 2 n + chains that aggregate via extensive hydrogen bonding. {[Cd(3-bpmp) 3(H 2O) 2](ClO 4) 2·5H 2O} n ( 2, 3-bpmp = bis(3-pyridylmethyl)piperazine) manifests 1-D coordination polymer chains with curled, pendant monodentate 3-bpmp ligands. {[Cd(H 2O) 4(4-bpmp)] 2[Cd(H 2O) 3(SO 4)(4-bpmp)][Cd(H 2O) 2(SO 4) 2(4-bpmp)]·10H 2O} n ( 3) displays sets of cationic [ Cd ( H 2 O ) 4 ( 4 -bpmp ) ] n 2 n + chains, neutral [Cd(H 2O) 3(SO 4)(4-bpmp)] n chains and anionic [ Cd ( H 2 O ) 2 ( SO 4 ) 2 ( 4 -bpmp ) ] n 2 n - chains linked into a pseudo 3-D lattice via numerous hydrogen bonding interactions. {CdSO 4(H 2O) 3(3-bpmp) 0.5] n ( 4) possesses a 2-D layered structure in which cadmium ions are connected by bridging 3-bpmp tethers and ligated sulfate ions. All four coordination polymers undergo blue–violet luminescence upon exposure to ultraviolet light.

Luminescent Cadmium Sulfide Nanochains Templated on Unfixed Deoxyribonucleic Acid and Their Fractal Alignment by Droplet Dewetting

A method for self-assembly of cadmium sulfide (CdS) nanochains (NCs) was proposed by direct deposition of CdS on unfixed DNA (DNA) template with 2-aminoethanethiol as a capping agent. The fractal alignment of CdS NCs on meniscus was then addressed utilizing droplet dewetting. The morphologies of CdS NCs were characterized with transmission electron microscopy, and their luminescent behaviors were investigated by photoluminescence and electrogenerated chemiluminescence (ECL). The presence of DNA scaffolds resulted in perfect surface status and efficient ECL of CdS NCs. The ECL mechanism and the heterogeneous nucleation process were also discussed. Adjusting the molar ratio of DNA to cadmium cation for synthesis could efficiently control the eventual NCs fractal on meniscus during the droplet dewetting and the properties of obtained NCs. The preferred pattern was formed at the molar ratio of 1:1. The present strategy provides a new way to synthesize and align nanowire devices without fixation of DNA and presynthesis of quantum dots (QDs) and has a potential applicability in pattern manufacture in natural way.

An acentric luminescent cadmium dimethylsuccinate/bipyridine coordination polymer with an uncommon three-dimensional CdSO 4 topology

The acentric coordination polymer {[Cd(dms)(4,4′-bpy)(H 2O) 2] · H 2O} n ( 1, dms = 2,2-dimethylsuccinate, 4,4′-bpy = 4,4′-bipyridine) has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. Fourfold one-dimensional (1-D) homochiral right-handed helical [Cd(dms)] n chain motifs are conjoined through tethering 4,4′-bpy ligands to construct a three-dimensional (3-D) network with uncommon CdSO 4 (6 58) topology. Irradition of 1 with ultraviolet light results in blue–violet luminescence.

Cluster synthesis of branched CdTe nanocrystals for use in light-emitting diodes

Highly luminescent cadmium telluride (CdTe) nanocrystals were synthesized usingLi2[Cd4(SPh)10] as a reactive Cd cluster compound at relatively low temperature, making it a safe precursorfor the large scale synthesis of CdTe nanocrystals. Transmission electron microscopy(TEM) showed that the shape of the CdTe nanocrystals changes from nanorods tobranched structures with increasing reaction time. The nanocrystals show highluminescent quantum yields up to 37% for CdTe branched nanostructures, and ashigh as 52% for CdTe/CdS core–shell heterostructures. CdTe/CdS nanocrystalswere used to make light-emitting diodes in combination with organic layers forelectron and hole injection. The devices show a maximum luminance efficiency of0.35 cd A−1.

Surface-modified nanoparticles via thermal and Cu(i)-mediated “click” chemistry: Generation of luminescent CdSe nanoparticles with polar ligands guiding supramolecular recognition

A new, simple and highly versatile method for the surface modification of luminescent cadmium selenide nanoparticles (CdSe NPs) based on 1,3-dipolar cycloaddition reactions is described. Uniform, trioctylphosphine oxide (TOPO)-covered CdSe NPs were prepared and subjected to two ligand-exchange reactions: first, ligand exchange was accomplished with pyridine, fully removing the TOPO ligand from the CdSe surface. In a second step, either 1-[(3-azidopropyl)octylphosphinoyl]octane or hex-5-ynoic acid 3-(dioctylphosphinoyl)propyl ester were added, attaching an azido or an acetylene moiety to the NP surface. Further thermal or Cu(I)-mediated 1,3-dipolar cycloaddition reactions on the residual azido/acetylene moieties with a variety of acetylenes/azides furnished the modified CdSe NPs with supramolecular receptors (i.e. barbituric acid, thymine, oligoethyleneglycol) on their surface. Photoluminescence measurements reveal a ∼50% residual quantum yield (relative to TOPO-covered CdSe NPs) after ligand modification, thus presenting an efficient pathway towards luminescent, surface modified CdSe NPs. The presence of the different functional groups was proven by 1H-NMR, 31P-NMR spectroscopy and by use of a nanoparticle-bound spiropyran dye and subsequent fluorescence quenching experiments. In order to further exploit the ligands on the CdSe NP surfaces, supramolecular recognition via binding to self-assembled monolayers (SAMs) presenting the matching receptor was investigated, leading to dense layers of CdSe NPs on planar surfaces as verified by AFM measurements. The concept offers a simple method for guiding the binding and recognition of luminescent CdSe NPs and related NPs onto surfaces.

Synthesis of high-luminescent cadmium sulfide nanocrystallites by a novel single-source precursor route

Highly luminescent cadmium sulfide nanocrystallites have been successfully produced by the thermolysis of a novel single-source precursor, cadmium O, O′-dialkyldithiophosphates, which were dissolved in oleic amine. The microstructure and morphology of the as-prepared CdS nanoparticles were characterized using X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy. It was found that the as-prepared CdS nanoparticles show a narrow size distribution and high crystallinity. The optical properties of these samples were examined by UV–visible and photoluminescence spectroscopy. Not only an intensive red-light-emitting luminescence phenomenon derived from the solution of the CdS nanocrystallites can be observed easily at room temperature, the band gap of CdS nanocrystallites can also be tailored by changing the length of substituted alkyl chain of single-source precursors.

Photostability of luminescent water-soluble cadmium selenide nanocrystals with chemical surface modification

We have developed a method for solubilization of hydrophobic CdSe/ZnS nanocrystals of the core/shell type, obtained by high-temperature synthesis in coordinating organic solvents. The method is based on chemical modification of the surface of the nanocrystals with hydrophilic organic mercapto compounds. We have observed that long-chain mercaptoundecanoic acid molecules effectively protect the surface of CdSe/ZnS nanocrystals in water, increasing (compared with short-chain molecules) the photostability of the nanocrystals.

Synthesis and crystal structure of a novel luminescent cadmium complex

A novel cadmium complex Cd(IPA)2(phen)2 (IPAH = isophthanic acid, phen = 1,10-phenanthroline) was synthesized by hydrothermal methods and characterized structurally by X-ray diffraction. The complex possesses a monomeric molecular structure. Cd(IPA)2(phen)2 is orthorhombic, space group Aba2, with a = 14.670(7), b = 22.876(8), c = 9.473(6) Å, V = 3179(3) Å3, D c = 1.573 Mg m−3, Z = 4, F(000) = 1520, GOF = 1.027, R1 = 0.0299, wR2 = 0.0617. Photophysical properties (fluorescence excitation and emission spectra) are reported.

SYNTHESIS OF POLYSTYRENE ENCAPSULATEDZnS-COATEDCdSeNANOCOMPOSITES MODIFIED WITH PLL–PEI–PEG–FA

Current cell tags using dyes lose their luminescence quickly and are not suitable for optical barcoding. Semiconductor quantum dots (QDs), on the other hand, can be engineered to emit different wavelengths, thus permitting tagging of various cells at the same time. Core/shell luminescent quantum dots, cadmium selenide ( CdSe ) and zinc sulphide ( ZnS ), were synthesized and incorporated into polystyrene (PS) particles grafted with carboxyl groups using microemulsion polymerization method. Highly luminescent monodispersed PS particles with diameters from 30 nm to 50 nm were chosen for subsequent surface modification. Two series of surface modifications were carried out with PS particles. One was modified with poly(L-Lysine) (PLL), polyethylenimine (PEI), Poly(Ethylene Glycol) (PEG) and folic acid (FA) side chains in sequence through chemical bonding. Another was conjugated with PEG and FA in sequence. The folic acid side chains can enter target cells via folate receptors and assisted in the uptake of the luminescent particles into the cells. This property allows them to be used as fluorescent labels for marking their ingress into cells and also for a cornucopia of biomedical applications.

Synthesis and Crystal Structure of Blue Luminescent Cadmium(II) Coordination Networks with 4,4′-Bis(imidazol-1-ylmethyl)biphenyl from Different Solvent Systems

Two supramolecular complexes, [Cd(bimb)2Cl2] (1) and [Cd(bimb)(DMF)Cl2]·DMF (2) [bimb=4,4′-bis(imidazol-1-ylmethyl)biphenyl], were synthesized by reactions of CdCl2·2.5H2O with bimb ligand in ethanol and N,N′-dimethylformamide (DMF), respectively, and their structures were determined by X-ray crystallography. Complex 1 is an infinite 2D grid network bridged by bimb ligands, and the 2D sheets were further linked by C–H ⃛Cl hydrogen bonds to form a polycatenated 3D framework. Complex 2 has dicadmium(II) di-μ-chloride units which are connected by bimb bridging ligands to form an infinite non-interpenetrating 2D network. The results provide a nice example of the solvent system exerting a great effect on the construction of supramolecular frameworks.

The synthesis of luminescent adenosine triphosphate passivated cadmium sulfide nanoparticles

A simple method of preparing luminescent cadmium sulfide nanoparticles passivated with the biological molecule adenosine triphosphate (ATP) is reported. The biological molecule ATP is used as a materials chemistry synthon rather than a biological entity and its interaction with a semiconductor quantum dot surface is investigated.

ChemInform Abstract: A Hybrid Electrochemical/Chemical Synthesis of Supported, Luminescent Cadmium Sulfide Nanocrystals.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A Hybrid Electrochemical/Chemical Synthesis of Supported, Luminescent Cadmium Sulfide Nanocrystals

A hybrid electrochemical/chemical (E/C) method is employed to synthesize epitaxially oriented CdS nanocrystallitessize selectivelyon graphite surfaces. The E/C synthesis involves three steps: (1) ...

Luminescent tellurium-doped cadmium sulphide electrodes as probes of semiconductor excited-state deactivation processes in photoelectrochemical cells

Correlations among quantum efficiencies for photocurrent (φx), emission (φr), and non-radiative recombination (φnr) are discussed with reference to data from single-crystal, n-type, 100 and 1000 p.p.m. CdS: Te-based photoelectrochemical cells (PECs) employing aqueous sulphide electrolyte. These materials emit while they serve as PEC electrodes. The assumption that the proportionality of φr to φnr is unaffected by potential, leads to a simple expression relating φx to φr for monochromatic excitation. Calculated and observed emission data are in reasonable agreement; sources of deviation are discussed. Polychromatic excitation is shown to yield photocurrents and emission intensities which are approximately a weighted average of the values obtained with the constituent monochromatic frequencies. Practical implications of the φx correlation with φr are described, as are related results from other PECs.