Organic soluble deoxyribonucleic acid (DNA) bearing carbazole moieties and its blend with phosphorescent Ir(III) complexes

A functionalized deoxyribonucleic acid (Cz‐DNA) was prepared with carbazolyl ammonium lipid as a triplet host material for phosphorescent material system. It is soluble in organic solvents, which facilitates the sample preparation for the absorption and luminescent properties in solid states. A highly soluble iridium complex, Ir(Cz‐ppy)₃ with carbazolyl‐substituted 2‐phenylpyridine ligands was employed for studying the phosphorescence in Cz‐DNA. There is a good overlap between the photoluminescence spectrum of Cz‐DNA and the metal‐to‐ligand charge transfer (MLCT) absorption bands of the iridium complex. This overlap enables efficient energy transfer from the excited state in the host to the MLCT band of Ir(Cz‐ppy)₃. In addition, photoluminescence quantum yield of Cz‐DNA was found to be relatively larger than the copolymer (PCzSt) with vinylcarbazole and styrene. Thus, Cz‐DNA was employed as a triplet host material for fabricating multilayered electrophosphorescence devices via modification of its property by doping 5,4‐tert‐butylhexyl‐1,3,4‐oxadiazole (PBD). After doping 30 wt % PBD and 10 wt % Ir(Cz‐ppy)₃ into Cz‐DNA, we achieved much improvement in electron injection/transport from an adjacent carrier transport layer, resulting in much improved device performances. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1913–1918, 2010     

Deep‐red light‐emitting phosphorescent dendrimer encapsulated tris‐[2‐benzo[b]thiophen‐2‐yl‐pyridyl] iridium (III) core for light‐emitting device applications

New deep‐red light‐emitting phosphorescent dendrimers with hole‐transporting carbazole dendrons were synthesized by reacting tris(2‐benzo[b]thiophen‐2‐yl‐pyridyl) iridium (III) complex with carbazolyl dendrons by DCC‐catalyzed esterification. The resulting first‐, second‐, and third‐generation dendrimers were found to be highly efficient as solution‐processable emitting materials and for use in host‐free electrophosphorescent light‐emitting diodes. We fabricated a host‐free dendrimer EL device with configuration ITO/PEDOT:PSS (40 nm)/dendrimer (55 nm)/BCP (10 nm)/Alq₃ (40 nm)/LiF (1 nm)/Al (100 nm) and characterized the device performance. The multilayered devices showed luminance of 561 cd/m² at 383.4 mA/cm² (12 V) for 15 , 1302 cd/m² at 321.3 mA/cm² (14 V) for 16 , and 422 cd/m² at 94.4 mA/cm² (18 V) for 17 . The third‐generation dendrimer, 17 (η_ext = 6.12% at 7.5 V), showed the highest external quantum efficiency (EQE) with an increase in the density of the light‐harvesting carbazole dendron. Three dendrimers exhibited considerably pure deep‐red emission with CIE 1931 (Commission International de L'Eclairage) chromaticity coordinates of x = 0.70, y = 0.30. The CIE coordinates remained very stable with the current density. The integration of rigid hole‐transporting dendrons and phosphorescent complexes provides a new route to design highly efficient solution‐processable materials for dendrimer light‐emitting diode (DLED) applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7517–7533, 2008     

Spectroscopic and electrochemical study for evaluating DNA interaction activity of 4‐(3‐halophenyl)‐6‐(pyridin‐2‐yl)pyrimidin‐2‐amine based piano stool Cp* Rh (III) and Ir (III) complexes

Six novel organometallic half sandwich complexes [(η5‐C₅Me₅)M(L^1–3)Cl]Cl.2H₂O were synthesized using [{(η⁵‐C₅Me₅)M(μ‐Cl)Cl₂], where M = Ir (III)/Rh (III) and L^1–3 = three pyridyl pyrimidine based ligands; and characterized by NMR, Infra‐red spectroscopy, conductance, elemental and thermal analysis. The complex‐DNA binding mode and/or strength evaluated using absorption titration, electrochemical studies and hydrodynamic measurement proposed intercalative binding mode, which was also confirmed by molecular docking study. Differential pulse voltammetry and cyclic voltammetry studies indicated an alteration in oxidation and reduction potentials of complexes (M⁺⁴/M⁺³) in presence of CT‐DNA. The metal complexes can cleave plasmid DNA as proposed in gel electrophoretic analysis. The LC₅₀ values of complexes evaluated on brine shrimp suggested their potent cytotoxic nature.     

Synthesis and characterization of a bis‐(4‐trifluoromethanesulfonyloxyphenyl)phenylamine monomer and its polymer for light‐emitting applications

This study focuses on the preparation, polymerization, characterization, and optical properties of a new bis‐(4‐trifluoromethanesulfonyloxyphenyl)phenylamine monomer. This is the first nitrogen‐containing monomer having nitrogen atoms as bridges between phenyl rings, and it was synthesized in three steps. The polymerization was carried out through the Ni(0)‐catalyzed homocoupling reaction of the bis‐(4‐trifluoromethanesulfonyloxyphenyl)phenylamine compound. The resulting polymer, polybis(paraphenyl)phenylamine, emitted an intense blue color (where λ = 415 nm) upon irradiation by ultraviolet light. The photoluminescence quantum yield was found to be 36% with a long excited‐state lifetime of 3.3 ns. Electrical conductivity data for an HCl‐doped film of the polymer were also examined. This novel polymer is of interest as an organic emitting material for electroluminescent devices. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1860–1867, 2007     

Cascade hole transport in efficient green phosphorescent light‐emitting devices achieved by layer‐by‐layer solution deposition using photocrosslinkable‐conjugated polymers containing oxetane side‐chain moieties

A hole‐injection/transport bilayer structure on an indium tin oxide (ITO) layer was fabricated using two photocrosslinkable polymers with different molecular energy levels. Two photoreactive polymers were synthesized using 2,7‐(or 3,6‐)‐dibromo‐9‐(6‐((3‐methyloxetan‐3‐yl)methoxy)hexyl)‐9H‐carbazole) and 2,4‐dimethyl‐N,N‐bis(4‐ (4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)phenyl)aniline via a Suzuki coupling reaction. When the oxetane groups were photopolymerized in the presence of a cationic photoinitiator, the photocured film showed good solvent resistance and compatibility with a poly(N‐vinylcarbazole) (PVK)‐based emitting layer. Without the use of a conventional hole injection layer (HIL) of poly(3,4‐ethylenedioxythiophene)/(polystyrenesulfonate) (PEDOT:PSS), the resulting green light‐emitting device bearing PVK: 5‐4‐tert‐butylphenyl‐1,3,4‐oxadiazole (PBD):Ir(Cz‐ppy)3 exhibited a maximum external quantum efficiency of 9.69%; this corresponds to a luminous efficiency of 29.57 cd/A for the device K‐4 configuration ITO/POx‐I/POx‐II/PVK:PBD:Ir(Cz‐ppy)3/triazole/Alq3/LiF/Al. These values are much higher than those of PLEDs using conventional PEDOT:PSS as a single HIL. The significant improvement in device efficiency is the result of suppression of the hole injection/transport properties through double‐layered photocrosslinked‐conjugated polymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Efficient blue‐emitting Ir(III) complexes with phenyl‐methyl‐benzimidazolyl and picolinate ligands: A DFT and time‐dependent DFT study

The series of heteroleptic cyclometalated Ir(III) complexes for organic light‐emitting display application have been investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, electronic structures, and the lowest‐lying singlet absorptions and triplet emissions of Ir‐(pmb)₃ and theoretically designed models Ir‐(Rpmb)₂pic were investigated with density functional theory (DFT)‐based approaches, where pmb = phenyl‐methyl‐benzimidazolyl, pic = picolinate, and R = H/F. Their structures in the ground and excited states have been optimized at the DFT/B3LYP/LANL2DZ and TDDFT/B3LYP/LANL2DZ levels, and the lowest absorptions and emissions were evaluated at B3LYP and M062X level of theory, respectively. The mobility of holes and electrons were studied computationally based on the Marcus theory. Calculations of ionization potentials were used to evaluate the injection abilities of holes into these complexes. The reasons for the higher electroluminescence efficiency and phosphorescence quantum yields in Ir‐(Rpmb)₂pic than in Ir‐(pmb)₃ have been investigated. The designed moleculars are expected to be highly emissive in pure‐blue region. © 2013 Wiley Periodicals, Inc.     

Triplet harvesting in poly(9‐vinylcarbazole) and poly(9‐(2,3‐epoxypropyl)carbazole) doped with CdSe/ZnS quantum dots encapsulated with 16‐(N‐carbazolyl) hexadecanoic acid ligands

Semiconductor quantum dots (QDs) can be used as alternative for transition metal complexes to harvest the nonemissive triplet excitons in organic light‐emitting diodes (OLEDs). In search for a QD‐based OLED material generating blue emission, poly(9‐vinylcarbazole) (PVK) and poly(9‐(2,3‐epoxypropyl) carbazole) (PEPK) are chosen as host for blue‐emitting CdSe/ZnS core/shell QDs. The QDs are encapsulated with 16‐(N‐carbazolyl) hexadecanoic acid (C16), a ligand terminated by a carbazole moiety. As alternative for PVK, PEPK, where the lower molecular weight and less extensive excimer formation could promise a better film formation and more extensive exciton hopping, is explored. The efficiencies of singlet ( ) and triplet ( ) energy transfer to the C16 capped QDs are estimated by combining stationary photoluminescence spectra and fluorescence decays of pristine polymer films with those of polymer films doped with the QDs. At a loading of 30 wt % of the QDs, increases from 12 ± 1% in PVK to 41 ± 2% in PEPK while increases from 37 ± 22% in PVK to 72 ± 48% in PEPK. The investigation of the film morphology by atomic force microscopy confirms that the main factor limiting the triplet transfer efficiency in the PVK matrix is the clustering of the C16 capped QDs. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 539–551     

A one‐dimensional lead(II) coordination polymer with terminal and bridging 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands

In the coordination polymer catena‐poly[[[diaqua[5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ²N³,O⁴]lead(II)]‐μ‐5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ³N³,O⁴:N²] dihydrate], {[Pb(C₁₀H₆N₃O₄)(H₂O)₂]·2H₂O}_n, the two 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands have different coordination modes, one being terminal and the other bridging. The bridging ligand links Pb^II cations into one‐dimensional coordination polymer chains. The structure is also stabilized by intra‐ and interchain π–π stacking interactions between the pyridine rings, resulting in the formation of a two‐dimensional network. Extensive hydrogen‐bonding interactions lead to the formation of a three‐dimensional supramolecular network.     

Novel 9,9′‐(1,3‐phenylene)bis‐9H‐carbazole‐containing copolymers as hole‐transporting and host materials for blue phosphorescent polymer light‐emitting diodes

Novel photo‐crosslinkable hole‐transport and host materials incorporated into multilayer blue phosphorescent polymer light‐emitting diodes (Ph‐PLEDs) were demonstrated in this study. The oxetane‐containing copolymers, which function as hole‐transport layers (HTL), could be cured by UV irradiation in the presence of a cationic photoinitiator. The composition of the two monomers was varied to yield three different hole‐transporting copolymers, [Poly(9,9′‐(5‐(((4‐(7‐(4‐(((3‐methyloxetan‐3‐yl)methoxy)methyl)phenyl)octan‐3‐yl)benzyl)oxy)methyl)?1,3‐phenylene)bis(9H‐carbazole)) ( P(mCP‐Ox)‐I , ‐II , and ‐III )]. In addition, monomer 1 was copolymerized with styrene to produce copolymer P(mCP‐Ph) as a host material for bis[2‐(4,6‐difluorophenyl)pyridinato‐C²,N](picolinato)iridium(III) (FIrpic), a blue‐emitting dopant. All mCP‐based copolymers displayed high glass transition temperatures (T_g) of up to 130–140 °C and triplet energies of up to 3.00 eV. The blue Ph‐PLEDs exhibited a maximum external quantum efficiency of 2.55%, in addition to a luminous efficiency of 8.75 cd A^?1 when using the device configuration of indium tin oxide/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate)/ P(mCP‐OX)‐III / P(mCP‐Ph) :FIrpic(15 wt %)/3,3′‐[5′‐[3‐(3‐pyridinyl)phenyl][1,1′:3′,1′′‐terphenyl]‐3,3′′‐diyl]bispyridine/LiF/Al. The device bearing P(mCP‐Ox)‐III HTL, containing the highest composition of mCP unit, exhibited better performance than the other devices, which is attributed to induction of more balanced charge carriers and carrier recombination in the emissive layer. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 707–718     

The characteristic of photoluminescence of tris‐(7‐substituted‐8‐hydroxyquinoline) aluminum complexes and polymeric complexes

The 7‐allyl‐ and 7‐(2‐methylvinyl)‐functionalized derivatives of 8‐hydroquinoline are synthesized by Claisen rearrangement and double bond rearrangement respectively. Then 7‐allyl‐8‐hydroquinoline (C) and 7‐(2‐methylvinyl)‐8‐hydroquinoline (D) are reacted with aluminum chloride to afford the corresponding tris‐(7‐allyl‐8‐hydroxyquinoline) aluminum complex (F) and tris‐(7‐(2‐methylvinyl)‐8‐hydroxyquinoline) aluminum complex (G). The photoluminescence of complex (F) or (G), compared with that of tris‐(8‐hydroxyquinoline) aluminum complex (E), all showed a red shift in emission wavelengths in different solvents, such as chloroform, hexane and ethanol. For two substituents containing an external double bond, the 2‐methylvinyl group gives a larger red shift in the emission wavelength than the allyl group. The X‐ray crystal structure indicates that 7‐(2‐methylvinyl)‐8‐hydroxyquinoline (D) is a trans‐isomer. The styrene and 7‐allyl‐8‐hydroxyquinoline copolymer, and the styrene and 7‐(2‐methylvinyl)‐8‐hydroxyquinoline copolymer are also reported. Further reactions of the copolymer are then performed by adding aluminum(III) chloride and ligands 8‐hydroxyquinoline. The spectroscopic characteristics of these aluminum(III) polymeric complexes are discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

CdII and CoII coordination polymers constructed from benzene‐1,4‐dicarboxylic acid and 2‐(pyridin‐3‐yl)‐1H‐benzimidazole ligands

In poly[aqua(μ₃‐benzene‐1,4‐dicarboxylato‐κ⁵O¹,O^1′:O¹:O⁴,O^4′)[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cadmium(II)], [Cd(C₈H₄O₄)(C₁₂H₉N₃)(H₂O)]_n, (I), each Cd^II ion is seven‐coordinated by the pyridine N atom from a 2‐(pyridin‐3‐yl)benzimidazole (3‐PyBIm) ligand, five O atoms from three benzene‐1,4‐dicarboxylate (1,4‐bdc) ligands and one O atom from a coordinated water molecule. The complex forms an extended two‐dimensional carboxylate layer structure, which is further extended into a three‐dimensional network by hydrogen‐bonding interactions. In catena‐poly[[diaquabis[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cobalt(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₉N₃)₂(H₂O)₂]_n, (II), each Co^II ion is six‐coordinated by two pyridine N atoms from two 3‐PyBIm ligands, two O atoms from two 1,4‐bdc ligands and two O atoms from two coordinated water molecules. The complex forms a one‐dimensional chain‐like coordination polymer and is further assembled by hydrogen‐bonding interactions to form a three‐dimensional network.     

Greenish‐yellow‐, yellow‐, and orange‐light‐emitting iridium(III) polypyridyl complexes with poly(ε‐caprolactone)–bipyridine macroligands

A set of novel greenish‐yellow‐, yellow‐, and orange‐light‐emitting polymeric iridium(III) complexes were synthesized with the bridge‐splitting method. The respective dimeric precursor complexes, [Ir(ppy)₂‐μ‐Cl]₂ (ppy = 2‐phenylpyridine) and [Ir(ppy? CHO)₂‐μ‐Cl]₂ [ppy? CHO = 4‐(2‐pyridyl)benzaldehyde], were coordinated to 2,2′‐bipyridine carrying poly(ε‐caprolactone) tails. The resulting emissive polymers were characterized with one‐dimensional (¹H) and two‐dimensional (¹H? ¹H correlation spectroscopy) nuclear magnetic resonance and infrared spectroscopy, gel permeation chromatography, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, and the successful coordination of the iridium(III) centers to the 2,2′‐bipyridine macroligand was revealed. The thermal behavior was studied with differential scanning calorimetry and correlated with atomic force microscopy. Furthermore, the quantitative coordination was verified by both the photophysical and electrochemical properties of the mononuclear iridium(III) compounds. The photoluminescence spectra showed strong emissions at 535 and 570 nm. The color shifts depended on the substituents of the cyclometallating ligands. Cyclic voltammetry gave oxidation potentials of 1.23 V and 1.46 V. Upon the excitation of the films at 365 nm, yellow light was observed, and this could allow potential applications in light‐emitting devices. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2765–2776, 2005     

A two‐dimensional cadmium(II) coordination polymer constructed from 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate and 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate ligands

Crystals of poly[[aqua[μ₃‐4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylato‐κ⁵O¹O^1′:N³,O⁴:O⁵][μ₄‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylato‐κ⁷N³,O⁴:O⁴,O^4′:O¹,O^1′:O¹]cadmium(II)] monohydrate], {[Cd₂(C₁₅H₁₄N₂O₄)(C₁₆H₁₄N₂O₆)(H₂O)]·H₂O}_n or {[Cd₂(Hcpimda)(cpima)(H₂O)]·H₂O}_n, (I), were obtained from 1‐(4‐carboxybenzyl)‐2‐propyl‐1H‐imidazole‐4,5‐dicarboxylic acid (H₃cpimda) and cadmium(II) chloride under hydrothermal conditions. The structure indicates that in‐situ decarboxylation of H₃cpimda occurred during the synthesis process. The asymmetric unit consists of two Cd²⁺ centres, one 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate (Hcpimda²⁻) anion, one 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate (cpima²⁻) anion, one coordinated water molecule and one lattice water molecule. One Cd²⁺ centre, i.e. Cd1, is hexacoordinated and displays a slightly distorted octahedral CdN₂O₄ geometry. The other Cd centre, i.e. Cd2, is coordinated by seven O atoms originating from one Hcpimda²⁻ ligand and three cpima²⁻ ligands. This Cd²⁺ centre can be described as having a distorted capped octahedral coordination geometry. Two carboxylate groups of the benzoate moieties of two cpima²⁻ ligands bridge between Cd2 centres to generate [Cd₂O₂] units, which are further linked by two cpima²⁻ ligands to produce one‐dimensional (1D) infinite chains based around large 26‐membered rings. Meanwhile, adjacent Cd1 centres are linked by Hcpimda²⁻ ligands to generate 1D zigzag chains. The two types of chains are linked through a μ₂‐η² bidentate bridging mode from an O atom of an imidazole carboxylate unit of cpima²⁻ to give a two‐dimensional (2D) coordination polymer. The simplified 2D net structure can be described as a 3,6‐coordinated net which has a (4³)₂(4⁶.6⁶.8³) topology. Furthermore, the FT–IR spectroscopic properties, photoluminescence properties, powder X‐ray diffraction (PXRD) pattern and thermogravimetric behaviour of the polymer have been investigated.     

A two‐dimensional cadmium(II) coordination polymer based on 5‐(pyridin‐4‐yl)isophthalic acid: poly[[tetraaquabis[μ3‐5‐(pyridin‐4‐yl)isophthalato]dicadmium(II)] pentahydrate]

The title Cd^II compound, {[Cd₂(C₁₃H₇NO₄)₂(H₂O)₄]·5H₂O}_n, was synthesized by the hydrothermal reaction of Cd(NO₃)₂·4H₂O and 5‐(pyridin‐4‐yl)isophthalic acid (H₂L). The asymmetric unit contains two crystallographically independent Cd^II cations, two deprotonated L²⁻ ligands, four coordinated water molecules and five isolated water molecules. One of the Cd^II cations adopts a six‐coordinate octahedral coordination geometry involving three O atoms from one bidentate chelating and one monodentate carboxylate group of two different L²⁻ ligands, one N atom of another L²⁻ ligand and two coordinated water molecules. The second Cd^II cation adopts a seven‐coordinate pentagonal–bipyramidal coordination geometry involving four O atoms from two bidentate chelating carboxylate groups of two different L²⁻ ligands, one N atom of another L²⁻ ligand and two coordinated water molecules. Each L²⁻ ligand bridges three Cd^II cations and, likewise, each Cd^II cation connects to three L²⁻ ligands, giving rise to a two‐dimensional graphite‐like 6³ layer structure. These two‐dimensional layers are further linked by O—H...O hydrogen‐bonding interactions to form a three‐dimensional supramolecular architecture. The photoluminescence properties of the title compound were also investigated.     

Mixed iridium(III) and ruthenium(II) polypyridyl complexes containing poly(ε‐caprolactone)‐bipyridine macroligands

A hydroxy‐functionalized bipyridine ligand was polymerized with ε‐caprolactone utilizing the controlled ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate. The resulting poly(ε‐caprolactone)‐containing bipyridine was characterized by ¹H NMR and IR spectroscopy, and gel permeation chromatography, as well as matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, revealing the successful incorporation of the bipyridine ligand into the polymer chain. Coordination to iridium(III) and ruthenium(II) precursor complexes yielded two macroligand complexes, which were characterized by NMR, gel permeation chromatography, matrix‐assisted laser desorption/ionization time‐of‐flight MS, cyclic voltammetry, and differential scanning calorimetry. In addition, both photophysical and electrochemical properties of the metal‐containing polymers proved the formation of a trisruthenium(II) and a trisiridium(III) polypyridyl species, respectively. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4153–4160, 2004     

A two‐dimensional CdII coordination polymer with 2,2′‐(disulfanediyl)dibenzoate and 1,10‐phenanthroline ligands

In poly[[μ₃‐2,2′‐(disulfanediyl)dibenzoato‐κ⁵O:O,O′:O′′,O′′′](1,10‐phenanthroline‐κ²N,N′)cadmium(II)], [Cd(C₁₄H₈O₄S₂)(C₁₂H₈N₂)]_n, the asymmetric unit contains one Cd^II cation, one 2,2′‐(disulfanediyl)dibenzoate anion (denoted dtdb²⁻) and one 1,10‐phenanthroline ligand (denoted phen). Each Cd^II centre is seven‐coordinated by five O atoms of bridging/chelating carboxylate groups from three dtdb²⁻ ligands and by two N atoms from one phen ligand, forming a distorted pentagonal–bipyramidal geometry. The Cd^II cations are bridged by dtdb²⁻ anions to give a two‐dimensional (4,4) layer. The layers are stacked to generate a three‐dimensional supramolecular architecture via a combination of aromatic C—H...π and π–π interactions. The thermogravimetric and luminescence properties of this compound were also investigated.     

Synthesis,structures and magnetic properties of a series of polynuclear copper(II)‐lanthanide( III) complexes assembled with carboxylate and hydroxide ligands

Heterometallic copper(II)‐lanthanide(III) complexes have been made with a variety of exclusively O‐donor ligands including betaines (zwitterionic carboxylates) and chloroacetate, which are dinuclear CuLn, tetranuclear Cu₂Ln₂, pentanuclear C_u3Ln₂, and octadecanuclear C_u12 complexes. The results show that subtle changes in both the carboxylates and acidity of the reaction solution can cause drastic changes in the structures of the products. Magnetic studies exhibit that shielding of the Ln³⁺ 4f electrons by the outer shell electrons is very effective to preclude significant coupling interaction between the Ln³⁺ 4f electrons and Cu²⁺ 3d electrons in either a mono‐atomic hydroxide‐bridged, or a carboxylate‐bridged system.     

A new one‐dimensional coordination polymer of 5‐(1,3‐dioxo‐4,5,6,7‐tetraphenylisoindolin‐2‐yl)isophthalic acid with manganese

The coordination polymer catena‐poly[[(dimethylformamide‐κO)[μ₃‐5‐(1,3‐dioxo‐4,5,6,7‐tetraphenylisoindolin‐2‐yl)isophthalato‐κ⁴O¹,O^1′:O³:O^3′](methanol‐κO)manganese(III)] dimethylformamide monosolvate], {[Mn(C₄₀H₂₃NO₆)(CH₃OH)(C₃H₇NO)]·C₃H₇NO}_n, has been synthesized from the reaction of 5‐(1,3‐dioxo‐4,5,6,7‐tetraphenylisoindolin‐2‐yl)isophthalic acid and manganese(II) acetate tetrahydrate in a glass tube at room temperature by solvent diffusion. The Mn^II centre is hexacoordinated by two O atoms from one chelating carboxylate group, by two O atoms from two monodentate carboxylate groups and by one O atom each from a methanol and a dimethylformamide (DMF) ligand. The single‐crystal structure crystallizes in the triclinic space group P. Moreover, the coordination polymer shows one‐dimensional 2‐connected {0} uninodal chain networks, and free DMF molecules are connected to the chains by O—H...O hydrogen bonds. The thermogravimetric and photoluminescent properties of the compound have also been investigated.     

A two‐dimensional mixed‐valence CuII/CuI coordination polymer constructed from 2‐(pyridin‐3‐yl)‐1H‐imidazole‐4,5‐dicarboxylate

Coordination polymers are a thriving class of functional solid‐state materials and there have been noticeable efforts and progress toward designing periodic functional structures with desired geometrical attributes and chemical properties for targeted applications. Self‐assembly of metal ions and organic ligands is one of the most efficient and widely utilized methods for the construction of CPs under hydro(solvo)thermal conditions. 2‐(Pyridin‐3‐yl)‐1H‐imidazole‐4,5‐dicarboxylate (HPIDC²⁻) has been proven to be an excellent multidentate ligand due to its multiple deprotonation and coordination modes. Crystals of poly[aquabis[μ₃‐5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ⁵N¹,O⁵:N³,O⁴:N²]copper(II)dicopper(I)], [Cu^IICu^I₂(C₁₀H₅N₃O₄)₂(H₂O)]_n, (I), were obtained from 2‐(pyridin‐3‐yl)‐1H‐imidazole‐4,5‐dicarboxylic acid (H₃PIDC) and copper(II) chloride under hydrothermal conditions. The asymmetric unit consists of one independent Cu^II ion, two Cu^I ions, two HPIDC²⁻ ligands and one coordinated water molecule. The Cu^II centre displays a square‐pyramidal geometry (CuN₂O₃), with two N,O‐chelating HPIDC²⁻ ligands occupying the basal plane in a trans geometry and one O atom from a coordinated water molecule in the axial position. The Cu^I atoms adopt three‐coordinated Y‐shaped coordinations. In each [CuN₂O] unit, deprotonated HPIDC²⁻ acts as an N,O‐chelating ligand, and a symmetry‐equivalent HPIDC²⁻ ligand acts as an N‐atom donor via the pyridine group. The HPIDC²⁻ ligands in the polymer serve as T‐shaped 3‐connectors and adopt a μ₃‐κ²N,O:κ²N′,O′:κN′′‐coordination mode, linking one Cu^II and two Cu^I cations. The Cu cations are arranged in one‐dimensional –Cu1–Cu2–Cu3– chains along the [001] direction. Further crosslinking of these chains by HPIDC²⁻ ligands along the b axis in a –Cu2–HPIDC²⁻–Cu3–HPIDC²⁻–Cu1– sequence results in a two‐dimensional polymer in the (100) plane. The resulting (2,3)‐connected net has a (12³)₂(12)₃ topology. Powder X‐ray diffraction confirmed the phase purity for (I), and susceptibilty measurements indicated a very weak ferromagnetic behaviour. A thermogravimetric analysis shows the loss of the apical aqua ligand before decomposition of the title compound.     

A 2D Metal‐Organic Framework Based on 9‐(Pyridin‐4‐yl)‐9H‐carbazole‐3,6‐dicarboxylic Acid: Synthesis,Structure and Properties

A metal‐organic framework (MOF ) formulated as [Cd₂(μ₃‐L)₂(DMF )₄]•H₂O ( CdL ) [H₂L =9‐(pyridin‐4‐yl)‐ 9H ‐carbazole‐3,6‐dicarboxylic acid, DMF =N ,N ‐dimethylformamide] was synthesized under solvothermal condition. Crystal structural analysis reveals that CdL features the layered 2D framework with L^{2 −} ligands as 3‐connected nodes. The compound CdL emits blue‐violet light with the narrow emission peak and the emission maximum at 414 nm upon excitation at the maximum excitation wavelength of 340 nm. The compound CdL has a similar emission spectrum curve to the free H₂L ligand that indicates the emission of compound CdL should be originated from the coordinated L^{2 −} ligands.