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We present the synthesis and characterization of seven new organic co-poly-ynes P1--P7 incorporating the phenothiazine (PTZ) motif and evaluate their optoelectronic properties and performance in polymer light-emitting diodes and polymer solar cells (PLEDs/PSCs). The co-poly-ynes were obtained in moderate to high yields via Sonogashira coupling reactions and characterized using analytical, spectroscopic and electrochemical techniques and complementary quantum-chemical modelling. The materials show strong optical absorption in the visible region of the spectrum and most also show strong emission with quantum yields in the range of 13-41% relative to rhodamine 6G (R6G). PLED devices based on the co-poly-ynes were prepared and the most promising was measured to have a brightness of up to 1.10 x 104 cd m-2. PSCs based on donor materials incorporating some of the polymers were prepared and demonstrated power conversion efficiencies of up to 0.24%. [ABSTRACT FROM AUTHOR]

We prove that any simple planar travelling wave solution to the membrane equation in spatial dimension d ≥ 3 with bounded spatial extent is globally nonlinearly stable under sufficiently small compactly supported perturbations, where the smallness depends on the size of the support of the perturbation as well as on the initial travelling wave profile. The main novelty of the argument is the lack of higher order peeling in our vector-field-based method. In particular, the higher order energies (in fact, all energies at order 2 or higher) are allowed to grow polynomially (but in a controlled way) in time. This is in contrast with classical global stability arguments, where only the 'top' order energies used in the bootstrap argument exhibit growth, and reflects the fact that the background travelling wave solution has 'infinite energy' and the coefficients of the perturbation equation are not asymptotically Lorentz invariant. Nonetheless, we can prove that the perturbation converges to zero in C² by carefully analysing the nonlinear interactions and exposing a certain 'vestigial' null structure in the equations. [ABSTRACT FROM AUTHOR]

The photophysical properties of two previously synthesized, highly efficient, bright red emitting complexes [Eu(btfa)3DPEPO] (CIE, 0.672; 0.326) (Eu-1) and [Eu(nta)3DPEPO] (CIE, 0.673; 0.326) (Eu-2) (btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione, nta = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione and DPEPO = bis(2-(diphenylphosphino)phenyl)ether oxide) are reported. The complexes have been used as dopants to fabricate several single and double emitting layer (EML) electroluminescent (EL) devices. At the optimum doping concentration of 4 wt%, the single EML device of Eu-1 exhibited a pure red color with an external quantum efficiency (EQE) of 2.9% and a maximum brightness (B) = 1320 cd m-2, maximum current efficiency (Zc) = 4.08 cd A-1, maximum power efficiency (Zp) = 3.37 lm W-1 with a very low turn-on voltage (Vturn-on) = 3.8 V. Importantly, the single EML device of Eu-2 at the optimum doping concentration exhibited pure red EL with EQE of 6.0% with the best EL performance: B = 2108 cd m-2, Zc = 8.45 cd A-1, and Zp = 6.98 lm W-1 at a very low Vturn-on = 3.5 V. The performances of this device are among the best reported for devices incorporating a europium complex as a red emitter. Furthermore, the EL performances were achieved at the current density of 10 mA cm-2, thereby alleviating a serious efficiency rolloff as a major obstacle to the development of Eu-complex based EL devices. [ABSTRACT FROM AUTHOR]

Integrating together two dissimilar π-conjugated molecules into controlled complex topological configurations remains a largely unsolved problem owing to the diversity of organic species and their respective different assembly features. Here, we find that two structurally similar organic semiconductors, 9,10-bis(phenylethynyl)anthracene (BA) and 5,12-bis(phenylethynyl)naphthacene (BN), co-assemble into two-component helices by control of the growth kinetics as well as the molar ratio of BA/BN. The helical superstructures made of planar and twisted bis(phenylethynyl) derivatives can be regarded as (BA)x(BN)1-x alloys, which are formed due to compatible structural relationship between BA and BN. Moreover, epitaxial growth of (BA)x(BN)1-x alloy layer on the surface of BA tube to form BA@(BA)x(BN)1-x core-shell structure is also achieved via a solute exchange process. The precise control over composition and morphology towards organic alloy helices and core-shell microstructures opens a door for understanding the complex co-assembly features of two or more different material partners with similar structures. [ABSTRACT FROM AUTHOR]

A novel near-infrared luminogen (TPE/TPY-Pt-PA/PEG) based on the terpyridyl Pt(II) complex with a tetraphenylethene periphery is synthesised and characterised. It displays aggregation-induced emission with the formation of self-assembled nanostructures. The nanoparticles fabricated with TPE/TPY-Pt-PA/PEG show excellent biocompatibility with high specificity to lysosomes in HeLa cells. [ABSTRACT FROM AUTHOR]

In a 2004 paper, Lindblad demonstrated that the minimal surface equation on ℝ1,1 describing graphical timelike minimal surfaces embedded in ℝ1,2 enjoy small data global existence for compactly supported initial data, using Christodoulou's conformal method. Here we give a different, geometric proof of the same fact, which exposes more clearly the inherent null structure of the equations, and which allows us to also close the argument using relatively few derivatives and mild decay assumptions at infinity. [ABSTRACT FROM AUTHOR]

Candida albicans (C. albicans) is an opportunistic fungal pathogen, particularly observed in immunocompromised patients. C. albicans accounts for 50-70% of cases of invasive candidiasis in the majority of clinical settings. Terbinafine, an allylamine antifungal drug, has been used to treat fungal infections previously. It has fungistatic activity against C. albicans. Traditional Chinese medicines can be used as complementary medicines to conventional drugs to treat a variety of ailments and diseases. Berberine is a quaternary alkaloid isolated from the traditional Chinese herb, Coptidis Rhizoma, while berberrubine is isolated from the medicinal plant Berberis vulgaris, but is also readily derived from berberine by pyrolysis. The present study demonstrates the possible complementary use of berberine and berberrubine with terbinafine against C. albicans. The experimental findings assume that the potential application of these alkaloids together with reduced dosage of the standard drug would enhance the resulting antifungal potency. [ABSTRACT FROM AUTHOR]

A phosphorescent CO2 gas probe based on an iridium(III) complex with 2-phenylimidazo-[4,5-f][1,10] phenanthroline ligand has been developed. Its phosphorescence is quenched by the addition of CH3COO-1. The quenched phosphorescence can be recovered by bubbling CO2 into the detecting solution. This phosphorescent CO2 probe exhibits higher photostability and reduced photobleaching than some of the reported organic fluorescent probes. A time-resolved photoluminescence experiment was performed for CO2 gas detection, which could effectively remove the background fluorescence and improve the sensitivity and signal-to-noise ratio of the sensor in complicated media. [ABSTRACT FROM AUTHOR]

Mononuclear Cu(I) complexes based on bis(pyrazol-1-yl-methyl)-pyridine derivatives and ancillary triphenylphosphine have been prepared and characterized by 1H NMR, mass spectroscopy and single-crystal X-ray analysis. The thermogravimetric analysis shows that the complexes exhibit high thermal stability. The electronic absorption spectra display two features in the regions of 230-260 and 290-350 nm attributable to mixed ligand-to-ligand (LLCT) and metal-to-ligand-charge-transfer (MLCT) excited states, which is supported by the results of density functional theory (DFT) and time-dependent DFT (TDDFT) calculations on these Cu(I) complexes. These complexes are strongly emissive in the solid state at ambient temperature. Intense blue or green emission in the poly(methyl methacrylate) film is observed in the region of 475-518 nm for these complexes with the emission lifetimes in the microsecond time scale (12-20 μs), indicating that the emission may be phosphorescence emission. Increasing the steric hindrance of the substituents on the pyrazole unit results in a blue-shift of the emission bands and enhanced emission quantum efficiency in PMMA films. The two most emissive complexes have been used for the fabrication of phosphorescent organic light-emitting diodes (POLEDs). [ABSTRACT FROM AUTHOR]

A new synthesis route for preparing Dawson-type polyoxometalate (POM) based inorganic-organic hybrid materials is presented. Two new heteropolytungstate-based dimeric and oligomeric Pt(II) acetylide inorganic-organic hybrid compounds (2PtOD and PPtOD) were prepared by Hagihara's dehydrohalogenating coupling of a terminal diacetylene POM hybrid containing diphosphoryl functionality and an appropriate platinum(II) halide precursor. This method provides a rigid covalent linkage between the POM and the organometallic Pt(II) acetylide moiety. The redox potential of the polyanion can be tuned by grafting the organic and organometallic groups on it. The photoelectric properties of hybrid LB films derived from these inorganic-organic composites were studied. [ABSTRACT FROM AUTHOR]

A new approach has been illustrated for the development of stable, efficient, and environmentally "friendly" white phosphorescent materials. Under mild conditions, a new one-dimensional coordination polymer has been prepared from benzo-18-crown-6 with CuI in the presence of KI, which is capable of emitting direct white light in the solid state. [ABSTRACT FROM AUTHOR]

Four new heteroleptic ruthenium sensitizers [Ru(4,4′-carboxylic acid-2,2′-bipyridine)(L)(NCS)2] (L = 5,5′-bis(4-octylthiophen-2-yl)-2,2′-bipyridine (1), 5,5′-bis(N,N-diphenyl-4-aminophenyl)-2,2′-bipyridine (2), 5,5′-bis(5-(N,N-diphenyl-4-aminophenyl)-thiophen-2-yl)-2,2′-bipyridine (3) and 5,5′-bis(4-octyl-5-(N,N-diphenyl-4-aminophenyl)-thiophen-2-yl)-2,2′-bipyridine (4)) were synthesized, characterized by physicochemical and computational methods, and utilized as photosensitizers in nanocrystalline dye-sensitized solar cells (DSSCs). The λmaxof the metal-to-ligand charge transfer (MLCT) absorption of these four ruthenium dyes (527 nm for 1, 535 nm for 2, 585 nm for 3and 553 nm for 4) can be tuned by various structural modifications of the ancillary ligand and it was shown that increasing the conjugation length of such ligand reduces the energy as well as the molar absorption coefficient of the MLCT band. The maximum incident photon to current conversion efficiency (IPCE) of 41.4% at 550 nm, 38.6% at 480 nm, 39.4% at 470 nm and 31.1% at 480 nm for 1-, 2-, 3- and 4-sensitized solar cells were obtained. Respectable power conversion efficiencies of 3.00%, 2.51%, 2.00% and 2.03% were realized, respectively, when the sensitizers 1, 2, 3and 4were used in DSSCs under the standard air mass (AM) 1.5 sunlight illumination (versus5.9% for standard N719). [ABSTRACT FROM AUTHOR]

Treatment of [NnBu4][OsVI(N)Cl4] with a stoichiometric amount of H2L (L = N,N′-bis(salicylidene)-o-cyclohexylenediamine dianion) in the presence of PF6−or ClO4−in MeOH affords [OsVI(N)(L)(OH2)](PF6) 1aand [OsVI(N)(L)(CH3OH)](ClO4) 1b, respectively. The structure of 1bhas been determined by X-ray crystallography and the OsN bond distance is 1.627(3) Å. In the presence of a N-donor heterocyclic ligand in CH3CN, 1areacts at room temperature to afford the mixed-valence μ-N2(salen)osmium species [(X)(L)OsIII–NN–OsII(L)(X)](PF6), 2–14(X = py 2; 4-Mepy 3; 4-tBupy 4; pz 5; 3-Mepz 6; 3,5-Me2pz 7; Im 8; 1-MeIm 9; 2-MeIm 10; 4-MeIm 11; 1,2-Me2Im 12; 2-Meozl 13; 4-MeTz 14). These complexes are formed by ligand-induced NN coupling of two [OsVIN]+to give initially [OsIII–N2–OsIII]2+, which is then reduced to give the more stable mixed-valence species [OsIII–N2–OsII]+. Cyclic voltammograms (CVs) of 2–14show two reversible couples, attributed to OsIII,III/OsIII,IIand OsIII,II/OsII,II. The large comproportionation constants (Kcom) of (5.36–82.3) × 1013indicate charge delocalization in these complexes. The structures of 3and 14have been determined by X-ray crystallography, the salen ligands are in uncommon cis-β configuration. Oxidations of 4and 14by [Cp2Fe](PF6) afford the symmetrical species [(X)(L)OsIII–NN–OsIII(L)(X)](PF6)2(X = 4-tBupy 15; 4-MeTz 16). These are the first stable μ-N2diosmium(iii,iii) complexes that have been characterized by X-ray crystallography. [ABSTRACT FROM AUTHOR]

The use of diethynylsilane, diethynyldisilane and diethynyldisiloxane in the synthesis of some linked metal carbonyl clusters is demonstrated. New dimeric η-diyne complexes of cobalt [{Co(CO)}(η-diyne)], ruthenium [{(μ-H)Ru(CO)}(μ-η,η-diyne)] and osmium [{(μ-CO)Os(CO)}(μ-η-diyne)] {diyne=HC≡CSi(CH)C≡CH, HC≡CSi(CH)–Si(CH)C≡CH, HC≡CSi(CH)–O–Si(CH)C≡CH or HC≡CSi(Ph)C≡CH} have been prepared in good yields from the reaction of [Co(CO)], [Ru(CO)] and [Os(CO)(NCMe)] with half an equivalent of the appropriate diyne ligand, respectively. All the twelve compounds have been characterized by IR and H NMR spectroscopies and mass spectrometry. The molecular structures of eight of them have been determined by X-ray crystallography. Structurally, each of the tetracobalt species displays two CoC cores adopting the pseudo-tetrahedral geometry with the alkyne bond lying essentially perpendicular to the Co–Co vector. For the group 8 ruthenium and osmium analogues, the hexanuclear carbonyl clusters consist of two trinuclear metal cores with the μ-η,η bonding mode for the acetylene groups in the former case and μ-(η-||) bonding mode in the latter one. Density functional theory was employed to study the electronic structures of these molecules in terms of the nature of the silyl or disilyl unit and its substituents. [ABSTRACT FROM AUTHOR]

A new series of organometallic/inorganic hybrid Langmuir-Blodgett (LB) films containing an organometallic gold(i) aryleneethynylene metal complex (OMA) as the π-conjugated organometallic molecule and a polyoxometalate (POM, POM = H3BW12O40, H6As2W18O62, or H6P2Mo18O62) of the Keggin and Dawson structure as the inorganic composite, were prepared and characterized by π–A isotherms, UV-vis absorption spectra, photoluminescence spectra, atomic force microscopy imaging, scanning tunnelling microscopy, and surface photovoltage spectroscopy. Our experimental results indicate that stable, well defined and well organized Langmuir and LB films are formed in pure water and polyoxometalate subphases. There is a quenching effect in the luminescence of the gold(i) complex when it is made into the LB films. The OMA/POM hybrid LB films display strong photovoltage effect in the UV-vis region. The photovoltage response of OMA/H6As2W18O62can be as high as 3338 μV. OMA/POM monolayer films show good electrical conductivity, and the tunnelling current for a OMA/H3BW12O40monolayer film amounts to 50 to approximately –100 nA when the voltage is set at ±9 V. [ABSTRACT FROM AUTHOR]

Reactions of heterobimetallic 3d–4f Schiff base complexes of the formula [ZnLnL(H2O)(NO3)3] (1a–e) with KOCN or NH4SCN in refluxing MeCN produce either one dimensional polymeric materials [ZnLnL(NO3)2(H2O)(OCN)]∞(2a–c) or trinuclear complexes of the formula [Zn2LnL2(NO3)(SCN)2] (3a–e) (a(La), b(Nd), c(Er), d(Tb), e(Eu); H2L = N,N′-bis-(3-methoxysalicylidene)ethylene-1,2-diamine). The structures of 2a,band 3b–ehave been determined by single-crystal X-ray diffraction studies. Structural differences between the complexes affect the photophysical properties, which have been studied in acetonitrile solutions. [ABSTRACT FROM AUTHOR]

Organic light-emitting diodes (OLEDs) show great promise of revolutionizing display technologies in the scientific community. One successful approach for improved device efficiency has been to maximize the electron-hole recombination using dopants that emit from the triplet excited state. In this context, heavy transition metal complexes have recently gained tremendous academic and industrial research interest for fabricating highly efficient phosphorescent OLEDs by taking advantage of the 1:3 exciton singlet/triplet ratio predicted by simple spin statistics. Traditional room-temperature phosphorescent dyes are monofunctional materials working only as light-emitting centres but other key issues including charge generation and transport remain to be addressed in the electroluminescence. This Feature Article highlights recent and current advances in developing new synthetic strategies for multifunctional organometallic phosphors, which integrate both luminescent and charge carrier injection/transport functions into the same molecules so that they perform most, if not all, of the necessary functional roles (viz. photoexcitation, charge injection and transport as well as recombination) for achieving high-efficiency devices. Considerable focus is placed on the design concepts towards the tuning capability of charge-transport characteristics and phosphorescence emission colour of this prominent class of metallophosphors. In particular, the latest research endeavor in accomplishing novel triplet emitters with enhanced charge injection/charge transport of both hole and electron carriers is criticially discussed, which can provide good implications regarding their possible routes for future research development in the field. [ABSTRACT FROM AUTHOR]

By fusing an electron-deficient ring system with the phenyl ring of a 2-phenylpyridine (ppy)-type ligand, a new and synthetically versatile strategy for the phosphorescence color tuning of cyclometalated iridium(III) and platinum(II) metallophosphors has been established. Two robust red electrophosphors with enhanced electron-injection/electron-transporting features were prepared by using an electron-trapping fluoren-9-one chromophore in the ligand design. The thermal, photophysical, redox and electrophosphorescent properties of these complexes are reported. These exciting results can be attributed to a switch of the metal-to-ligand charge-transfer (MLCT) character of the transition from the pyridyl groups in the traditional IrIIIor PtIIppy-type complexes to the electron-deficient ring core, and the spectral assignments corroborate well with the electrochemical data as well as the time-dependent density functional theory (TD-DFT) calculations. The electron-withdrawing character of the fused ring results in much more stable MLCT states, inducing a substantial red-shift of the triplet emission energy from yellow to red for the IrIIIcomplex and even green to red for the PtIIcounterpart. Electrophosphorescent organic light-emitting devices (OLEDs) doped with these red emitters fabricated by using vacuum evaporation technique have been realized with reasonable performance. [ABSTRACT FROM AUTHOR]

Three new transition metal complexes of 4,5-diazafluoren-9-one, [(DAFO)PdCl2], [(DAFO)PtCl2], and [(DAFO)ZnCl2], were prepared in good yields by the reactions between appropriate metal chloride precursors and 4,5-diazafluoren-9-one under ambient conditions. The structures of these metal complexes were established by spectroscopic (Fourier-transform IR, NMR, and fast-atom bombardment mass spectrometry) techniques. The possible biological activity of these compounds on three human cancer cell lines including Hep3B, MDAMB-231, and SKHep-1 was investigated. The results obtained showed that both zinc- and platinum-containing compounds exhibit a similar growth inhibitory effect on these three cancer cell lines when compared with the prototypical cis-platin. In contrast, the corresponding palladium congener is virtually biologically inactive in these trials. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and photophysics of some solution-processable intensely coloured polyplatinynes functionalized with the thienopyrazine–thiophene hybrid spacer and their model molecular complexes are described. These metallated polymers possess extremely low bandgaps of 1.47–1.50 eV, which extend towards the near-infrared (NIR) range of the solar spectrum, and represent the lowest optical bandgaps ever reported for metallopolyynes in the literature. Both polymers can be used to fabricate efficient solar cells with power conversion efficiencies (PCEs) of up to 0.63% under air mass (AM1.5) simulated solar illumination, and the possibility of covering the 600–900 nm solar-radiation range to harvest photocurrent has been demonstrated. The influence of the thienyl core as well as its substituent group, on the optical and photovoltaic behavior of these metallopolymers was investigated in detail. The power dependencies of the solar cell parameters (including the short-circuit current density, open-circuit voltage, fill-factor and PCE) were also studied. The present work offers an attractive avenue towards conjugated materials with broad solar absorptions and demonstrates the potential of metallopolyynes for both visible and NIR light power generation. [ABSTRACT FROM AUTHOR]

Abstract  A novel diblock copolymer with a polyrotaxane block α-cyclodextrins-poly (ε-caprolactone)-b-poly{2,5-bis[(4-methoxypheny)oxycabony]-styrene} (α-CD-PCL-b-PMPCS) was successfully synthesized by combining ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The diblock copolymer was confirmed by 1H NMR, GPC and solid-state 13C CP/MAS NMR spectroscopic analysis. Its phase structures and phase transitions were investigated by thermogravimetric analyses and wide-angle X-ray diffraction (WAXD). WAXD and solid-state 13C CP/MAS NMR spectroscopic study confirmed that inclusion complexes domains of the polyrotaxanes assumed a channel-type structure. [ABSTRACT FROM AUTHOR]

With the goal to provide organometallic triplet emitters with good hole-injection/hole-transporting properties, highly amorphous character for simple solution-processed organic light-emitting diodes, and negligible triplet–triplet (T–T) annihilation, a series of new phosphorescent cyclometalated IrIII and PtII complexes with triphenylamine-anchored fluorenylpyridine dendritic ligands were synthesized and characterized. The photophysical, thermal, electrochemical and electroluminescent properties of these molecules are reported. The incorporation of two sterically hindered electron-rich triphenylamino groups to the 9-position of the fluorene skeleton was found not only to afford triplet emitters in the glassy state with high Tg, but also to elevate the HOMO levels and confer the hole-injection ability to the phosphorescent center. These highly amorphous metal phosphors can serve as doped emitters in a small molecular host for spin-coated emission layer in suitable OLED structures to achieve good device performance with a maximum luminance of 29380 cd m−2 at 23 V, a peak external quantum efficiency of 7.0%, a luminance efficiency of 21.4 cd A−1 and a power efficiency of 2.9 lm W−1. Both the electrophosphorescent device characterization as well as the theoretical simulation results show that these iridium electrophosphors show negligible T–T annihilation even at high operating current densities and moderately high doping levels. Our investigations indicate that attaching the triphenylamino moieties to the fluorene ring is an effective way to overcome the T–T annihilation caused by the strong interactions among the emitting molecules. [ABSTRACT FROM AUTHOR]

Abstract  The difurylphosphido-bridged dinuclear complex [Ru2(CO)6(μ-PFu2)(μ-η1,η2-Fu)] (Fu = 2-furyl) 1 readily reacts with two equivalents of each of the terminal alkynes HC≡CR (R = Fc, p-C6H4Fc, p-C6H4NO2, Fc = Fe(η5-C5H5)(η5-C5H4)) by an interesting head-to-tail ynyl coupling with a furan group to form a series of phosphido-bridged diruthenium compounds containing a novel furyl-substituted C4 hydrocarbyl chain of stoichiometry [Ru2(CO)4(μ-PFu2){μ-η1,η1,η2,η3-RCC(H)C(R)C(H)Fu}] (R = Fc 2, p-C6H4Fc 3, p-C6H4NO2 4) in moderate to good yields. Reaction of 1 with an equimolar amount of HC≡CFc and HC≡C(p-C6H4NO2) afforded a pair of isomers of [Ru2(CO)4(μ-PFu2){μ-η1,η1,η2,η3-R1CC(H)C(R2)C(H)Fu}] (R1 = Fc, R2 = p-C6H4NO2 5a; R1 = p-C6H4NO2, R2 = Fc 5b) together with a small mixture of 4. X-ray crystal structures of 2, 3, 5a and 5b are reported. All of these new alkyne-derived dinuclear complexes are electron precise with 34 cluster valence electrons in which the μ-η1,η2-furyl ligand acts as a three-electron donor and the μ-phosphido Ru2 framework is retained in the products upon alkyne coupling reactions. The resulting organic fragment of each complex is coordinated to the Ru atoms via a π, a π-allyl and two σ bonds, and donates seven electrons to the metal core. [ABSTRACT FROM AUTHOR]

novel approach based on conjugation interruption was developed for a luminescent and thermally stable platinum(II) polyyne polymer trans-[-Pt(PBu)C≡C(CH)CH(CH)C≡C-] ( 1) containing the diphenylmethane chromophoric spacer. Particular attention was focused on the photophysical properties of this group 10 polymetallayne and comparison was made to its binuclear model complex trans-[Pt(Ph)(PEt)C≡C(CH)CH(CH)C≡CPt(Ph)(PEt)] ( 2) and their closest group 11 gold(I) and group 12 mercury(II) neighbors, [MC≡C(CH)CH(CH)C≡CM] (M = Au(PPh) ( 3), HgMe ( 4)). The regiochemical structures of these angular-shaped compounds were studied by various spectroscopic analyses. Upon photoexcitation, each of them emits an intense purple-blue fluorescence emission in the near UV region in dilute fluid solutions at room temperature. Harvesting of organic triplet emissions harnessed through the strong heavy-atom effects of group 10-12 transition metals was examined. These metal-containing phenyleneethynylenes spaced by the conjugation-breaking CH unit were found to have high optical gaps and high-energy triplet states. The influence of metal and sp-hybridized methylene conjugation-interrupters on the intersystem crossing rate and the spatial extent of the lowest singlet and triplet excitons was fully elucidated. Our investigations indicate that high-energy triplet states in these materials intrinsically give rise to very efficient phosphorescence with fast radiative decays. [ABSTRACT FROM AUTHOR]

With the simple dinuclear Zn–Nd complex [ZnNdL(H2O)(NO3)3] (1) (H2L = N,N′-bis(3-methoxysalicylidene)ethylene-1,2-diamine) as the precursor, tetranuclear [Zn2Nd2L2(4,4′-bpy)(NO3)6]·Et2O (2) and [Zn2Nd2L2(4,4′-bpe)]·2H2O (3) (4,4′-bpy = 4,4′-bipyridine, 4,4′-bpe = trans-bis(4-pyridyl)ethylene) complexes are formed: suitable choice of bidentate linkers could construct multinuclear heterometallic 3d–4f Schiff-base complexes with improved luminescent properties, and the controlling of linker character shows a potentially effective way to the fine-tuning properties of NIR luminescence from Nd ions. [ABSTRACT FROM AUTHOR]

Two new fluorescent ethenyl- and ethynyl-dimesitylboranes functionalized with a dansyl group 1 and 2 have been synthesized in good yields. Compound 1 was prepared by the hydroboration of 5-(dimethylamino)-N-(prop-2-ynyl)naphthalene-1-sulfonamide I with dimesitylborane (HB(Mes)2) in dry tetrahydrofuran at room temperature, and compound 2 was synthesized by Pd-catalyzed cross-coupling of I with 4-I-C6H4B(Mes)2. Both organoborane compounds 1 and 2 have been characterized by infrared spectroscopy, NMR spectroscopy, and mass spectrometry. The molecular structures of I and 1 were confirmed by X-ray crystallography. The electronic absorption and redox properties of 1 and 2 were investigated. They both exhibit large positive solvatochromism and their emission spectra have been recorded in a range of organic solvents with the fluorescence maxima exhibiting large bathochromic shifts in highly polar solvents, indicative of charge transfer which leads to large dipole moments in the excited state. The application of 1 as a blue fluorescent dopant in doped guest?host organic light-emitting diodes is also described. [ABSTRACT FROM AUTHOR]

This article highlights recent progress in the development of rigid-rod metallopolyyne polymers of late transition metals which can exhibit easily tunable luminescent and electronic properties. Considerable focus is placed on the design strategies towards the tuning capability of phosphorescence emission color and optical bandgap of this class of luminescent metallopolymers, and the evaluation of their suitability as emitters in light-emitting applications, optical power limiters for sensor protection and semiconductors in organometallic photovoltaic cells. An effective approach based on structural modification of the spacer group can be devised to achieve the full-color phosphorescence emission spanning almost the whole visible spectrum and to tune the material properties of these functional organometallic polymers. The major advances, ongoing challenges and future perspectives of this research frontier are also discussed. [ABSTRACT FROM AUTHOR]

Bulk heterojunction solar cells have been extensively studied owing to their great potential for cost-effective photovoltaic devices. Although recent advances resulted in the fabrication of poly(3-hexylthiophene) (P3HT)/fullerene derivative based solar cells with efficiencies in the range 4.4–5.0%, theoretical calculations predict that the development of novel donor materials with a lower bandgap is required to exceed the power-conversion efficiency of 10%. However, all of the lower bandgap polymers developed so far have failed to reach the efficiency of P3HT-based cells. To address this issue, we synthesized a soluble, intensely coloured platinum metallopolyyne with a low bandgap of 1.85 eV. The solar cells, containing metallopolyyne/fullerene derivative blends as the photoactive material, showed a power-conversion efficiency with an average of 4.1%, without annealing or the use of spacer layers needed to achieve comparable efficiency with P3HT. This clearly demonstrates the potential of metallated conjugated polymers for efficient photovoltaic devices. [ABSTRACT FROM AUTHOR]

Two new heterotrinuclear organorhenium(i) mercury(ii) derivatives of 4-ethynylpyridine [Re(CO)3Cl(NC5H4C?CHgMe)2] 1 and [Re(CO)3Cl(NC5H4C?CHgC?CC5H4N)2] 2 were prepared in good yields by the reaction of Re(CO)5Cl with a methylmercury(ii) derivative of 4-ethynylpyridine 1a and its inorganic mercury(ii) derivative, bis(4-pyridylethynyl)mercury 2a, respectively. The structures of these mixed-metal complexes were established by spectroscopic (FT-IR, NMR, and FABMS) techniques and their photophysical properties were examined in both fluid and solid phases. [ABSTRACT FROM AUTHOR]

series of light-emitting group 14 element-containing organometallic platinum polyynes of the form trans-[-Pt(PBu)C≡ CArC≡ C(ER)C≡ CArC≡ C-] (Ar = 9-butylcarbazole-3,6-diyl, ER = SiMe, SiPh, GeMe, GePh) were synthesized and spectroscopically characterized. The solution properties and regiochemical structures of this new structural class of organosilicon- and organogermanium-based metallopolyynes were studied by IR and NMR (H, C, Si, and P) spectroscopies. The optical absorption and photoluminescence spectra of these metallopolymers were examined and compared with their well-defined dinuclear model complexes trans-[Pt(Ph)(PEt)C≡ CArC≡ C(ER)C≡ CArC≡ CPt(Ph)(PEt)]. The influence of the heavy platinum atom and the group 14 silyl or germyl structural unit possessing different side group substituents on the thermal and phosphorescence properties were investigated in detail. We have also established the goal for studying the evolution of the lowest singlet and triplet excited states with the nature of ER unit in these metallopolymers. The present work indicates that the phosphorescence emission efficiency harnessed through the heavy-atom effect of platinum in the main chain changes significantly with the identity of ER in the general orders GeR > SiR (R = Me, Ph) and EMe > EPh (E = Si, Ge). [ABSTRACT FROM AUTHOR]

Abstract Thermal reaction of [Ru2(CO)6(µ-PFu2)(µ-?1,?2-Fu)] (Fu=2-furyl) with (9-anthracenyl)diphenylphosphine (AnPPh2) produces a novel diruthenium complex [Ru2(CO)5(µ-PFu2)(µ-?1,?1,?2-C14H8PPh2)] (1) in good yield whereas the corresponding reaction between [(µ-H)4Ru4(CO)12] and AnPPh2 gives [HRu(CO)3(PPh2C14H8)][(µ-H)4Ru4(CO)11(AnPPh2)] (2). Both compounds 1 and 2 were fully characterized by spectroscopic methods and their X-ray crystal structures were determined. For 1, initial coordination of the PPh2 functionality at the Ru atom is accompanied by cyclometalation of the anthracenyl ring to form a Ru–C s bond together with concomitant formation of a p bond to the adjacent Ru center and loss of the furyl ligand. The formation of 2 involves the cleavage of two Ru–Ru bonds, and the making of a Ru–P bond, followed by orthometalation of the anthracenyl ring. The optical absorption and emission spectra of 1 were recorded and the results were correlated to the DFT calculations. [ABSTRACT FROM AUTHOR]

Abstract This review briefly summarizes research work carried out by the author in the past decade on rigid-rod transition metal polyyne polymers and their molecular precursors. The research involves the synthesis, spectroscopic and photophysical characterization, ligand functionalization, and possible optoelectronic applications of transition metal polyyne polymers. Herein, oligomeric and polymeric metal alkynyl systems of the late transition metals are discussed, and particular attention is focused on the electronic absorption spectroscopy and photoluminescence behavior, thermal stability and structural aspects of these polymetallaynes. A detailed account of the evolution of the first excited singlet and triplet state on the electronic structure of the organic spacer groups of these metal polyyne polymers is also given and the interplaying factors that govern the spatial extent of the lowest-lying singlet and triplet energy levels for the chemical tailoring of the singlettriplet gap are elucidated. The possible developments of this research are also envisaged. [ABSTRACT FROM AUTHOR]