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Hydroamidation of carbon-carbon double bonds is an attractive strategy for installing nitrogen functionality into molecular scaffolds and, with it, increasing molecular complexity. To date, metal-based approaches have dominated this area of chemical synthesis, despite the drawbacks of air and moisture sensitivity, limited functional group tolerance, toxicity, and/or high cost often associated with using metals. Here, in offering an alternative solution, we disclose an operationally simple, metal-free, one-pot, regioselective, multicomponent synthetic procedure for the hydroamidation of carbon-carbon double bonds. This method features mild reaction conditions and utilizes isocyanides and vinyl ethers for the rapid and modular synthesis of privileged α-oxygenated amide scaffolds. In unraveling the mechanistic underpinning of this non-metal-based reactivity, we present kinetic solvent isotope effect studies, variable time normalization analysis, and density functional theory computations offering insight into the mechanism of this multistep catalytic hydroamidation process.

Charge-enhanced catalysis has emerged as a powerful alternative to the mainstream use of neutral catalysis. With this in mind, we report a catalytic Friedel‒Crafts alkylation method catalyzed by a charged thiourea incorporating a cationic cyclopropenium moiety. Mechanistic studies, including density functional theory computational calculations, variable time normalization analysis, and 1H NMR binding studies, collectively reveal this charge-enhanced reactivity proceeds by a dual hydrogen bond-mediated LUMO-lowering mode of substrate activation. Key to these findings is the observed steady-state concentration of the catalyst with in situ derived monomeric catalytic species predominating under the reaction conditions.

4,7-Bis-(4′-cyano-biphenyl-4-yl)-[1, 10]phenanthroline (cnbiphphen) is synthesized from a palladium mediated coupling between 4-cyanobenzene boronic acid and 4,7-bis(4-bromophenyl)-[1,10]phenanthroline. The single crystal X-ray structure was measured at both 298(2) K and 90(2) K. The asymmetric unit of the title compound in the low-temperature phase, C38H22N 4 . HCCl3, is comprised of one cnbiphphen molecule and one chloroform solvent molecule. Additional symmetry relates one-half of the title compound to the other at room temperature. During cooling the structure experiences a reversible phase transition from A 2/a (different setting of C 2/c, with a and c exchanged to match lattice parameters of both phases) to P 21/c. The crystal packing of the title compound consists primarily of electronic charge interactions between the cyano moieties. The chloroform solvent mol-ecule is situated in a cavity between two phenanthroline systems and is associated to two nitrogen atoms of cnbiphphen molecules through Cl3C–H⋯Nphen van der Waals interaction. The synthesis, structure, analytical characterization, optical properties and phase transition of 4,7-bis-(4’-cyano-biphenyl-4-yl)-[1,10]phenanthroline is presented.

We report the synthesis, X-ray structure, absorbance and emission of 4,7-bis(4-fluorophenyl)-1,10-phenanthroline and 4,7-bis-(4′-trifluoromethyl-biphenyl-4-yl)-1,10-phenanthroline. 4,7-Bis(4-fluorophenyl)-1,10-phenanthroline was synthesized by successive Skraup reactions and features absorbance at 274 nm and emission at 384 nm while 4,7-bis-(4′-trifluoromethyl-biphenyl-4-yl)-1,10-phenanthroline featured absorbance at 283 nm and emission at 400 nm. The structures show molecular stacking of the phenyl groups and phenanthroline structure and longitudinal fluorine atom associations within the crystal lattice. Furthermore, the three fused rings of the 4,7-bis(4-fluorophenyl)-1,10-phenanthroline unit exhibited torsion up to 13.97(9)° throughout the crystal lattice whereas no torsion is observed for 4,7-bis-(4′-trifluoromethyl-biphenyl-4-yl)-1,10-phenanthroline.

The spectroscopy, electrochemistry and electrogenerated chemiluminescence (ECL) of four osmium(II) phenanthroline carbonyl chloride complexes are reported. Three of these compounds also contain diphosphine chelating ligands. ECL is generated in acetonitrile solutions with tri- n -propylamine (TPrA) as an oxidative–reductive coreactant. ECL efficiencies ( ϕ ecl = photons emitted per redox event) between 0.011 and 0.13 were obtained in air saturated and deoxygenated solutions with Ru(bpy) 3 2+ (bpy = 2,2′-bipyridine) as a relative standard ( ϕ ecl = 1). The ECL intensity peaks at a potential corresponding to oxidation of both TPrA and the osmium systems, while ECL spectra (obtained using absorption filters) are similar to photoluminescence spectra, indicating that emission is from the excited states of the osmium complexes.

Pressure sensitive paints (PSP) that measure changes in barometric pressure through oxygen quenching are an important analytical tool in wind tunnel and other research. PSPs are often used during the development phase of new aircraft, cars, and trucks where the performance of the proposed vehicle is researched. Previously, many PSPs have been based upon charged phosphorescent metal complex salts that may have poor solubility in the oxygen permeable host material. Charge neutral phosphorescent dyes should have better solubility, and to demonstrate this, neutral osmium and iridium complexes are presented in this report. X-ray structures are measured and DFT calculations are used to explain many of their properties. The complexes are dissolved into poly(1,1,1,3,3,3-hexafluoroisopropylmethacrylate-co-1H,1H-dihydroperfluorobutyl-methacrylate) (FIB), an oxygen permeable host polymer. The complexes exhibit good solubility and compatibility with the FIB polymer. The photo-degradation, temperature sensitivity, and Stern–Volmer curves of PSPs based on these complexes are presented. The complexes show great promise for use in PSPs.

We report the synthesis of phosphorescent divalent osmium complexes of the form [Os(N–N) 2 (L–L) or Os(L–L) 2 (N–N)] 2+ (PF 6 ) 2 where N–N is a derivative of 1,10-phenanthroline, and L–L is a diarsine or diphosphine ligand: 1,2-bis(dimethylphosphino)ethane, 1,2-bis(dicyclohexylphosphino)ethane, or 1,2-bis(dimethylarseno)benzene. X-ray structures have been determined, luminescent and electrochemical properties have been measured and DFT calculations have been performed on the complexes. The emission lifetime of complexes of structure Os(II)(L–L) 2 (N–N) are longer than the those of Os(II)(N–N) 2 (L–L). The DFT calculations show that there is significant mixing of the π−π ∗ into the dπ−π ∗ charge-transfer state for the complexes of the form Os(II)(L–L) 2 (N–N) resulting in a longer lived excited state. Through DFT calculations we were able to conclude that the HOMO of the complexes is a d orbital on the osmium while the LUMO is the b 1 ( ψ ) π ∗ system of the phenanthroline. However, we found that the HOMO did not have the correct symmetry to enable strong charge transfer to the phenanthroline to be observed, and the strong MLCT transition observed in the spectra is the metal d HOMO(−1) to the b1 π ∗ LUMO of the phenanthroline.

We report new osmium complexes based upon the 2-[(diphenylphosphanyl)-methyl]-pyridine ligand. Hexafluorophosphate salts of bis(3,4,7,8-tetramethyl-1,10-phenantholine)(2-[(diphenylphosphanyl)-methyl]-pyridine)osmium(II) (1), and bis(2-[(diphenylphosphanyl)-methyl]-pyridine)(4,7-diphenyl-1,10-phenantholine)osmium(II) (2) have been synthesized, and X-ray structures have been obtained. Indexing and unit cell refinement of both 1 and 2 indicated a monoclinic P lattice. The space groups were found to be P1 (No. 2) and P21/c, respectively. Both 1 and 2 were found to have the same emission at 645 nm despite the differences in structure. Through density functional theory (DFT) calculations we were able to conclude that the highest occupied molecular orbital (HOMO) of the complexes is the dxy orbital on the osmium, while the lowest unoccupied molecular orbital (LUMO) is the b1(Ψ)π* system of the phenanthroline. However, we found that dxy did not have the correct orientation to enable charge transfer to the phenan...

Application of bis(propylenedioxythiophene) (bis(ProDOT)) π-conjugated bridges bearing alkyl or aryl substituents in electro-optic (EO) chromophores is presented. A series of three bis(ProDOT)-based chromophores and a bithiophene-based control chromophore were prepared and fully characterized with regard to EO applications. The highly planar bis(ProDOT) bridge results in slightly larger (∼10%) molecular hyperpolarizability (β) values as compared to the bithiophene bridge, as measured by hyper-Rayleigh scattering at a variety of wavelengths. In amorphous polycarbonate guest–host films, however, the bulky substituents on the bis(ProDOT) bridge result in significantly larger (∼70%) poling-induced EO coefficient (r33) values, as measured by simple reflection ellipsometry at 1310 nm. This can be attributed to a roughly 2-fold enhancement in poling efficiency due to reduced intermolecular dipole–dipole interactions. This chromophore architecture also exhibits excellent temporal alignment stability and photochem...

Divalent osmium complexes of the form [ Os ( N – N ) 2 L – L ] ( PF 6 - ) 2 where N–N was a polypyridyl, and L–L was either cis-1,2-bis(diphenylphosphino)ethene (dppene) or cis-1,2-vinylenebis(diphenylarsine) (dpaene) have been synthesized and characterized. X-ray structures were determined for three complexes and for the free dpaene molecule. It was observed that the P–C bond lengths, and C–P–C bond angles do not change significantly when complexed to osmium. It was observed the As–C bond lengths shorten by 2.3 pm and the C–As–C bond angles broaden by 5.6° when dpaene was complexed to osmium. These changes in the arsine structure may indicate a different method of backbonding between arsenic and osmium. It was found that the arsine complexes had absorption and emission that were to the red of analogous phosphine complexes. In violation of “energy gap law”, the dpaene complexes were found to have higher quantum yields. This may be due to the way that the arsenic atoms bond to osmium.

The preparation, photophysics, and solid-state structures of three osmium cored complexes are reported. The osmium complexes take the general form of [OsCl(N–N)(L–L)(CO)] þ hexafluorophosphate where N stands for a derivative of 1,10-phenanthroline and L stands for a phosphine type ligand. The emission of the complexes is shown to be blue shifted to the osmium emission of Os(bpy) 2þ 3 . The emissions of the various complexes range from yellow (560 nm) to yellow-green (550 nm) to green (520 nm). The quantum yields vary between 60% and 75%. The complexes show lifetimes that are much longer than expected with ranges of 6.5–38 ls. Crystallographic results show that the carbonyl is trans to a phenanthroline nitrogen and the chloro ligand is trans to phosphorus. A discussion will be presented as to the nature of the bonding in these complexes based upon the data from the crystallography.

Europium beta diketonates are easily synthesized highly luminescent complexes with high temperature sensitivity. We report on the temperature dependence of the luminescence of recently synthesized europium complexes originally prepared for use as light emitting diodes. It has been discovered that when incorporated in a polymer matrix, their decay lifetime can provide accurate measurement of temperature. Their lifetime as a function of temperature depends on three factors: (i) the type and number of ligands in the complex, (ii) the particular polymer used for the matrix, and (iii) the europium chelate to polymer matrix concentration ratio. Various tris and tetrakis europium chelates are used to study ligand effects, while the polymers FIB, polycarbonate, and Teflon© are used to analyze matrix effects. In all cases studied, higher concentrations give rise to shorter lifetimes and higher temperature sensitivities, with sensitivity defined as ΔI/(IrefΔT). We propose to explain this phenomenon by using the following equation: 1/τobs≡Ktotal=kr+knr(T)+kc([Eu]). Here Ktotal is the observed decay rate, which is the inverse of the observed lifetime, while kr and knr(T) are the radiative and nonradiative decay rates, respectively. As well as being dependent on temperature, knr(T) for these complexes is very dependent on the environment, i.e., solvent or polymer, and can be considered as ken(T). The rate kc([Eu]) is the quenching term dependent on the concentration of the europium complex.

Two newly synthesized luminescent compounds provide a lifetime based dual pressure and temperature sensor when jointly dissolved in a polymer matrix. The temperature sensor is a tris(β-diketonate) phenanthroline europium complex, with a broad absorption peaked at 370 nm and a characteristic but relatively sharp 615 nm europium emission. The lifetime of this compound varies between 260 and 120 μs over the temperature range 5–45 °C for a derivative of −3.50 μs/°C. Our pressure sensor is a porphyrin compound called platinum tetra(pentafluorophenyl)porpholactone (PtTFPL) developed recently in our labs. This compound has a principal absorption band at 390 nm and a red-shifted phosphorescence at 730 μm. In silicone polycarbonate co-polymer, PtTFPL has a lifetime range of 42.7–6.6 μs in going from 0 to 1 atm at 1 atm. The two sensors have maximum absorption in the range 370–400 nm but non-overlapping emission spectra upon excitation with a broadband illumination at 400 nm. As a result, with appropriate band pass optical filters, the two emission lines can be detected separately. In addition to the high photostability of the dual system, our studies show that the luminescence properties of one sensor are independent of the presence of the other sensor. We note that measurement of decay rate is more robust than measuring intensity, since it is unaffected by changes in the light source, the index of refraction of the medium, optical geometry variations and fluctuations in film thickness and dye concentration. Hence the two compounds afford the possibility of a dual luminophor lifetime measurement of pressure and temperature.

Pure and efficient red light-emitting diodes based on novel europium (Eu) and osmium (Os) complexes were demonstrated. The Eu complex, with dendron substituted diketone ligands, exhibits high photoluminescence efficiency of 45%. When a copolymer containing carbazole and 1,3,4-oxadiazole groups was used as the host, narrow electroluminescence at 617 nm was achieved, with a 'full width at half maximum of 4 nm and a maximum external quantum efficiency (η) of 0.80%, The Os complex shows pure red emission peaking at 650 nm. The Commission Internationale de l'Eclairage (CIE) chromaticity coordinates (x, y) are (0.65, 0.33). Maximum η and brightness achieved were 0.82% and 590 cd/m 2 , respectively.

The advanced corrosion resistant aircraft coatings program (ACRAC) is part of the Air Force strategy to improve performance and reduce environmental impact of coatings used on Air Force weapon systems. The program addresses the Air Force near and mid-term strategies to eliminate chromate corrosion inhibitors and reduce steps in the outer mold line coating process. Evaluation of the coating process (surface preparation, conversion coating, primer, topcoat) as a system is a key feature of the ACRAC program. Results to date indicate that the current-state-of-the-art nonchromated coating systems are significantly less effective than those with chromate. A chromate conversion coating is required for the nonchromate primer system to meet minimum requirements. Sol–gel-process based conversion coatings can replace chromate conversion coatings provided a chromated primer is used. Several approaches to incorporating inhibitors into sol–gel coatings are discussed. Electrochemical methods for testing coating performance are discussed and a new procedure based on impedance spectroscopy for evaluating active damage repair is presented.

The pressure sensitive paint (PSP) properties of a fluoroacrylic polymer, FIB, with the luminophor platinum tetra(pentafluorophenyl)porphine (PtTFPP) are presented. This paint forms a hard coating that displays Stern–Volmer plots with a high dynamic range (∼ 0.9) [defined as (Ivac − Iatm)/Ivac], good photostability, a response time of less than 1 s and a relatively low temperature dependence (∼ 0.6% per degree). The temperature dependence is low because FIB has a unusually low activation energy for the diffusion of oxygen. Pressure and temperature affect intensity independently making this PSP “ideal.” The basecoat affects the functionality of the PSP it underlies, and the optimal basecoat used to date also includes the FIB polymer. The synthesis of the FIB polymer is a copolymerization that occurs in one step with a peroxide initiator. Annealing the painted model above Tg = 70°C procures adhesion and ideality. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2795–2804, 2000

Recent advances in polymeric electro-optic materials and device fabrication techniques have significantly increased the potential for incorporation of these materials and devices into modern high bandwidth (fiber and wireless) telecommunication, information processing, and radar systems. Charge transfer π-electron chromophores characterized by molecular first hyperpolarizability (second order optical non-linearity) values approaching 3000×10 –30 esu have been synthesized. Elucidation of the role of intermolecular electrostatic interactions in inhibiting the efficient translation of molecular optical non-linearity to macroscopic electro-optic activity has permitted systematic modification of materials to achieve electro-optic coefficients approaching 100 pm V –1 . Improvements in the optical loss of polymeric materials at wavelengths of 1.3 and 1.55 µm have been effected. Mode matching of passive transmission and active electro-optic waveguides has been addressed, permitting a dramatic reduction in insertion loss. The putative ability of polymeric electro-optic materials to be efficiently integrated with very large scale integration semiconductor electronic circuitry and with passive optical circuitry has been demonstrated. Several devices of varying degrees of complexity have been fabricated and evaluated to operational frequencies as high as 150 GHz. The operational stability of polymeric devices is very competitive with devices fabricated from lithium niobate and gallium arsenide.

A series of efficient and bright double-layer light-emitting devices have been fabricated using the osmium (Os) complex as the triplet emissive dopant in both a blue-emitting polyfluorene derivative (PF–TPA–OXD) containing hole-transporting triphenylamine (TPA) and electron-transporting oxadiazole (OXD) as side chains and a blend of 2-(4-t-butylphenyl)-5(4-biphenylyl)-1,3,4-oxadizole (PBD) in poly(N-vinylcarbazole) (PVK). Due to a balanced charge injection and transport in PF–TPA–OXD and very efficient energy transfer from this polymer to the Os complex, the resulting device (indium tin oxide/HTL/OsCF3:PF–TPA–OXD/Ca/Ag) reaches a maximum external quantum efficiency of 2.1% with a peak brightness of 2920 cd/m2. These results are significantly higher than those obtained from the commonly used host, PVK:PBD (0.49% and 1270 cd/m2).

Efficient red electrophosphorescence was achieved from double-layer light-emitting devices using osmium (Os)-complexes-doped blend of poly(vinylnaphthalene) (PVN) and 2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole (PVN:PBD) as the emitting layer. Blending PVN with PBD greatly suppresses the electromer emission of PVN. The PVN:PBD blend emanates a short-wavelength electroluminescence emission peaking at around 375 nm, which overlaps well with the absorption spectra of the Os complexes and ensures very efficient energy transfer to the Os-complex dopants. The best external quantum efficiency of the double-layer devices was 2.2%, with a photometric efficiency of 1.9 cd/A.

We report red electrophosphorescence from light-emitting diodes based on osmium (Os) complexes. Efficient red emission was achieved using an in situ polymerized tetraphenyldiaminobiphenyl-containing polymer as the hole-transporting layer and Os complexes doped blend of poly(N-vinylcarbazole) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole as the emitting layer. The emission peaks of the reported Os complexes, ranging from 620 to 650 nm, can be tuned by changing the structures of the ligands because the emission originates from triplet metal-to-ligand-charge-transfer excited state. The Os complexes trap both electrons and holes, which facilitates the direct recombination of holes and electrons on the complex sites. The peak external quantum efficiency and brightness achieved from the complexes were 0.82% and 970 cd/m2, respectively. The Commission Internationale de I’Eclairage chromaticity coordinates (x,y) for the best red emission from the complexes are (0.65, 0.33).

The spectroscopy, electrochemistry and electrogenerated chemiluminescence (ECL) of five osmium(ii) polypyridyl systems containing either phosphine or arsine chelating ligands are reported. ECL is generated in acetonitrile and mixed CH(3)CN-H(2)O (50 : 50 v/v) solutions with tri-n-propylamine (TPrA) as an oxidative-reductive coreactant. ECL efficiencies (phi(ECL) = photons emitted per redox event) between 0.15 and 8.43 are obtained using Ru(bpy)(3)(2+) (bpy = 2,2'-bipyridine) as a relative standard (phi(ECL) = 1). The ECL efficiency is dependent on both the nature of the ligands and the solvent media. The ECL spectra are identical to photoluminescence spectra indicating formation of the same excited states in both ECL and PL.

Pressure sensitive paints (PSP) that measure the changes in air pressure have proved to be useful in the design of aircraft and other vehicles. In this study we incorporate highly luminescent divalent osmium complexes into PSP. The divalent osmium complexes were heptafluorobutyrate salts of [Os(N-N)2(L-L)]2+ or [Os(L-L)2(N-N)]2+, where N-N is a derivative of 1,10-phenanthroline, and L-L is a diphosphine or diarsine ligand. The complexes were dissolved into poly(1,1,1,3,3,3-hexafluoroisopropylmethacrylate-co-1H,1H-dihydroperflurobutylmethacrylate) (FIB) at a concentration of 0.002 g of complex to 1.000 g of polymer. The luminescence of the coatings was tested for pressure sensitivity, temperature dependence, and photodegradation. The paints featured strong pressure response, and the temperature dependence of the luminescence was measured as low as -0.11% degrees C(-1). Several of the complexes exhibited little photodegradation upon prolonged exposure to 400 nm light. These attributes make the complexes very desirable luminescent dyes for PSP.

Electrophosphorescence tuned from the green to red (522 nm – 650 nm) was achieved from double-layer light emitting devices using osmium (Os) complexes doped blend of either poly(vinylcarbazole) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PVK:PBD), or poly(vinyl naphthalene) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PVN:PBD) as the emitting layer. Blending PVN with PBD greatly suppresses the electromer emission of PVN. The PVN:PBD blend emanates a short wavelength EL emission peaking at around 375 nm, which well overlaps with the absorption spectra of the Os complexes and ensures very effi cient energy transfer to the Os complex dopants. PVK:PBD has an EL emission around 450 nm which does not overlap the absorption bands of the osmium complexes and also produces devices of lower efficiency, but PVK is a better transport layer and therefore produces brighter devices. The best external quantum efficiency of the double-layer devices was 2.2%, with a photometric efficiency of 1.9 cd/A. The brightest device achieved was 1,600 cd/m

There is a considerable interest in the use of metal centered materials as a light source in the growing field of organic light emitting devices (OLED's). In these devices, a polymeric host matrix containing either a carbazole type polymer or polyfluorene derivatives is used to help facilitate energy transfer to the luminophore. We have shown that by using a gadolinium complex that consist of three equivalents of a chelated dibenzoylmethane b-diketone ligand and one equivalent of a phenanthroline type ligand as a component in the host matrix, the performance of a double layer type OLED is improved. We have studied OLED systems that contain tris chelated europium compounds that contain three equivalents of partially fluorinated β-diketone type ligands and an equivalent of a phenanthroline type ligand. In these devices, the external efficiency has shown a 30-fold increase. We have also shown there is an increase for Osmium based OLED's that use the gadolinium complex as part of the polymer matrix. In these devices, the maximum quantum efficiency increased from 2.1% to a value of 3.8%.

In this work we present the synthesis and characterization of several novel osmium complexes of the form [Os(N-N) 2 L-L] 2+ 2X - designed for organic light emitting device (OLED) applications. In the complex notation N-N represents a derivative of 2,2'-bipyridine or 1,10-phenanthroline and L-L represents a strong π-acid arsine or phosphine ligand. The complexes feature 3 MLCT emission that ranges from 611 - 650 nm, which makes them suitable as an emission source for red OLEDs. Phosphorescent quantum yields as high as 45% and emission lifetimes as short as 400 nanoseconds have been reached.

Novel luminescent materials based on europium-cored complexes have been synthesized and incorporated intolight emitting diodes using poly (N-vinyl-carbazole) and poly (vinyl naphthalene) blends as doping hosts. Thecomplexes consists of fluorinated ! -diketone ligands chelated to europium. Excitation of the ligands and efficienttransfer of energy from the excited ligands to the metal core results in the emission of optically pure red light.The ligands were designed such that they include a polycyclic aromatic compound, phenanthrene, and a secondsubstituent to improve processibility. Phenanthrene is used to so that the ligand energy will match with the energy of themetal center. Partially fluorinated substituents were also used to help improve the efficiency and charge transfercapability of the resulting metal complex. The complex consisted of one equivalent of europium and three equivalentsof the ligand. One equivalent of either 1,10-phenanthroline or 4,7-diphenyl-1,10-phenanthroline was also chelated toenhance the stability of the complex.Double and triple layer devices were synthesized with the configuration of ITO/BTPD-PFCB/Europiumcomplex in a polymer blend/Ca/Ag for the double layer device and ITO/BTPD-PFCB/Europium complex in a polymerblend/PBD/Ca/Ag for the triple layer device. The double layer devices made with a polymer blend of PVNoutperformed the devices made from PVK as the emission bands of the PVN better match the absorption bands of theligands. A maximum brightness of 178 cd/m

In this work we present the synthesis and characterization of several novel osmium complexes of the form [Os(N-N)2 L-L]2+ 2Ts- or [Os(L-L)2 N-N]2+ 2Ts- designed for organic light emitting device (OLED) applications. In the complex notation N-N represents a derivative of 2,2'-bipyridine or 1,10-phenanthroline and L-L represents a strong π-acid arsine or phosphine ligand. Several counterions have been used and include tosylate, hexafluorophosphate, triflate, heptafluorobutyrate, chloride, bromide, and iodide. The complexes feature 3MLCT emission that ranges from 611-650 nm, which makes them suitable as an emission source for red OLEDs. Phosphorescent quantum yields as high as 45% and emission lifetimes as short as 400 nanoseconds have been reached. The complexes were incorporated into OLED and give off red, orange, yellow, and green electrophosphorescence. Red devices have been created using polyvinylcarb/2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole, polyvinylnapthalene/2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole, and polyfluorene host materials. OLEDs have been created which give brightness up to 3000 cd m-2 and efficiency up to 2.2% at 632 nm emission.

We report new divalent osmium complexes that feature strong red metal-to-ligand-charge-transfer (MLCT) phosphorescence and electrophosphorescence. The general formula of the complexes is Os(II)(N-N)(2)L-L, where N-N is either a bipyridine or a phenanthroline and L-L is either a phosphine or an arsine. New polypyridyl ligands synthesized are 4,4'-di(biphenyl)-2,2'-bipyridine (15) and 4,4'-di(diphenyl ether)-2,2'-bipyridine (16), and the 1,10-phenanthroline derivatives synthesized are 4,7-bis(p-methoxyphenyl)-1,10-phenanthroline (17), 4,7-bis(p-bromophenyl)-1,10-phenanthroline (18), 4,7-bis(4'-phenoxybiphen-4-yl)-1,10-phenanthroline (19), and 4,7-bis(4-naphth-2-ylphenyl)-1,10-phenanthroline (20). 4,4'-Diphenyl-2,2'-bipyridine (21) and 4,7-diphenyl-1,10-phenanthroline (22) were also used in these studies. Strong pi-acid ligands used were 1,2-bis(diphenylarseno)ethane (23), cis-1,2-bis(diphenylphosphino)ethylene (24), and cis-1,2-vinylenebis(diphenylarsine) (25). Ligand 25 is used for the first time in these types of luminescent osmium complexes. These compounds feature strong MLCT absorption bands in the visible region and strong red phosphorescent emission ranging from 611 to 651 nm, with quantum efficiency up to 45% in ethanol solution at room temperature. Red organic light-emitting diodes (OLEDs) were successfully fabricated by doping the Os(II) complexes into blend of poly(N-vinylcarbazole) (PVK) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD). Brightness over 1400 cd/m(2) for a double-layer device has been reached, with a turn-on voltage of 8 V. The maximum external quantum efficiency was 0.64%. Commission Internationale de l'Eclairage (CIE) chromaticity coordinates (x, y) of the red electrophosphorescence from the complexes are (0.65, 0.34), which indicates pure red emission.

Europium cored complexes may be used as a source of red emission in light emitting diodes. Novel europium cored complexes have been synthesized and incorporated into organic light emitting diodes (OLED's). These complexes emit red light at 615 nm with a full width half maximum (FWHM) of less than 5 nm. The europium complexes consist of one equivalent of europium chelated to three equivalents of a nonsymmetrical β-diketone ligand. The Claissen condensation of a polycyclic aromatic sensitizer and an ester of a fluorinated carboxylic acid create the ligands. The use of a sensitizer such as phenanthrene results in a ligand that has an emission band that directly overlaps with the absorption band of europium. The use of fluorinated chains improves the overall processibility as well as the charge transfer capability of the resulting metal cored complex. The europium core is further encapsulated by the inclusion of an additional polycyclic aromatic compound such as 4, 7 diphenyl - 1, 10 phenanthroline. Emission of 615 nm light is accomplished through excitation of the ligand and efficient Forrester energy transfer to the europium complex. A multiple layer device consisting of a substrate of indium tin oxide, followed by thin layers of BTPD-PFCB (with a thickness of 20nm), a polymer blend containing the europium complex (30 nm), followed by a layer of calcium (50nm) and finally a protective layer of silver (120 nm). The polymer blends were either poly(n-vinyl carbazole)(PVK) or poly vinyl naphthalene (PVN). The device performance was further improved by the incorporation of another lanthanide metal complex. These complexes were based upon similar ligands surrounding gadolinium. In these devices, there is a Dexter energy transfer as well as the Forster energy transfer. For the devices that are based on a PVN:PBD as a polymer host, the lowest turn on voltage was 12.0 volts. The devices that use PVK:TPD devices was 178 cd/m2 with an external quantum efficiency of 0.61%.For PVK:TKD the brightness was 116 cd/m2 with an external quantum efficiency of 0.048%. Devices that incorporate the gadolinium complexes have the turn on voltage of 5.6 volts. We report a maximum brightness of 201 cd/m2 with an external quantum efficiency of 1.0%.

The reaction of various [Os(L)(2)(L')](2+) complexes (where L and L' are phenanthroline, diphosphine or diarsine ligands) and organic reducing agents after chemical or electrochemical oxidation of the reactants produces an emission of light corresponding to MLCT transitions. In certain instances, the emission was greater than that of [Ru(bipy)(3)](2+), but the relative signals were dependent on many factors, including reagent concentration, mode of oxidation, reducing agent and the sensitivity of the photodetector over the wavelength range. Refereed/Peer-reviewed

The response times of pressure sensitive paint (PSP) and pressure sensitive microspheres to passing shockwaves were measured to investigate their ability to accurately determine pressure changes in unsteady flows. The PSPs tested used platinum tetra(pentafluorophenyl)porphine (PtTFPP), platinum octaethylporphine (PtOEP), and a novel set of osmium-based organometallic complexes as pressure sensitive luminophors incorporated into polymer matrices of dimethylsiloxane bisphenol A-polycarbonate block copolymer or polystyrene. Two types of pressure sensitive microspheres were used, the first being PtOEP-doped polystyrene microspheres (PSBeads) and the second being porous silicon dioxide microspheres containing the novel, pressure sensitive osmium complexes. Response times for the platinum-based PSPs ranged from 47.2 to 53.0 micros, while the osmium-based PSPs ranged between 37.6 and 58.9 micros. For the microspheres, 2.5 microm diameter PSBeads showed a response time of 3.15 ms, while the osmium-based silicon dioxide microspheres showed a response time ranging between 13.6 and 18.9 micros.