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A series of mono-, di-, and poly(platina-ynes) incorporating stilbene spacer units with the formulae trans-[R–CC–Pt(PBu3)2-CC–R] (R = (E)-1,2-diphenylethene), trans-[(Ph)-(Et3P)2PtCC–R–CCPt(PEt3)2(Ph)] (R = (E)-1,2-diphenylethene), and trans-[–(PnBu3)2PtCC–R–CC–]n (R = (E)-1,2-diphenylethene), respectively, have been synthesized and characterized to explore the effects of ligand topology on the photoisomerization and photophysical properties of these materials. The structural and photophysical properties of the complexes have been investigated and compared with those of the previously reported mono-, di- and poly(platina-ynes) incorporating azobenzene spacers. We found that the organometallic species 1M, 2M and 1P undergo topology-dependent reversible trans-to-cis photoisomerization in CH2Cl2 solution. Computational modelling supported the experimental findings.

Two new octa-coordinated ternary europium(III) complexes of the type [Eu(btfa)3(Br2-bpy)] (Eu-1) and [Eu(btfa)3(PhE2-bpy)] (Eu-2) (where btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione, Br2-bpy = 5,5′-dibromo-2,2′-bipyridine, PhE2-bpy 5,5′-bis(phenylethynyl)-2,2′-bipyridine) together with a previously reported complex [Eu(btfa)3(bpy)] (Eu-3) have been synthesized. The complexes have been characterized by analytical and spectroscopic methods. The photophysical properties of the complexes have also been analyzed both experimentally and theoretically. The contribution of each ligand to the sensitized Eu(III) photoluminescence (PL) has been analyzed and is discussed. An energy transfer (ET) mechanism is proposed and discussed for the sensitized Eu(III) emission using experimental and theoretical data. The Eu(III) complex incorporating the parent bpy showed impressive performance as a double-emitting layer (EML) red organic light emitting diodes (R-OLEDs).

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 (ηc) = 4.08 cd A−1, maximum power efficiency (ηp) = 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, ηc = 8.45 cd A−1, and ηp = 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 roll-off as a major obstacle to the development of Eu-complex based EL devices.

A new homodinuclear complex [Eu(btfa)3]2bpm (1) was synthesized incorporating 4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa) as the primary and 2,2′-bipyrimidine (bpm) as the auxiliary ligand. The complex was characterized by analytical and spectroscopic techniques, with special emphasis on the crystal structure and photoluminescence (PL) properties, both experimentally and theoretically. Single crystal X-ray diffraction (SCXRD) analysis reveals that the two Eu(III) ions in 1 are eight coordinate, where the bpm behaves as a N4 donor linking the two Eu(III) ions symmetrically. Each Eu(III) ion displays a distorted square antiprismatic (DSAP, D4d) coordination geometry. Complex 1 displayed bright red emission with (CIE)x,y color coordinates = 0.670; 0.330 and an absolute photoluminescence quantum yield (PLQY) of 54.4%. The theoretical intensity parameters (Ω2 and Ω4), radiative (AR) and non-radiative (ANR) decay rates, intrinsic quantum yield (QEuEu), sensitization efficiency (ηsen) and PLQY were assessed using the LUMPAC software and showed very good agreement with the experimental values. Based on these, an energy transfer (ET) mechanism is proposed and discussed. Moreover, 1 was used as an emitter to fabricate single- and double-emitting layer (EML) red-emitting electroluminescent devices. Double-EML device at the optimum doping concentration of 4.0 wt% displayed impressive EL performances, brightness (B) = 812 cd m−2, maximum current efficiency (ηc) = 3.97 cd A−1, maximum power efficiency (ηp) = 3.89 lm W−1, and external quantum efficiency (EQE) = 2.8% at very low Vturn-on = 3.2 V with (CIE)x,y = 0.662, 0.321 which is close to the standard red color recommended by NTSC (0.67, 0.33).

A new samarium complex [Sm(hfaa)3(Py-Im)] (ML) was synthesized by utilizing hexafluoroacetylacetone (hfaa) and 2-(2-pyridyl)benzimidazole (Py-Im) as coordinating ligands. Single crystal X-ray analysis shows that in the solid-state the complex dimerizes through intermolecular hydrogen-bonding with N-H?O (2.127 Å) and N-H?F (2.576 Å) interactions. The complex in the solid-state displayed highly monochromatic brilliant red emission with Commission International de I'Eclairage (CIE) color coordinates of 0.6532; 0.3336, with a remarkably long luminescence lifetime (?exp. ? 204.47 ± 4.043 ?s) and a high intrinsic quantum yield (QSmSm ? 6.60%). Furthermore, the complex in different organic media displayed color tunability from orange (CIE; 0.6071; 0.3568) to violet (CIE; 0.3634; 0.2144) with ?exp. from 105.50 ± 0.143 to 14.27 ± 0.033 ?s. Hybrid and flexible thin films obtained by doping different concentrations (1%, 2%, 4% and 6%) of the complex into the poly(urethane) (PU) polymer matrix also exhibited color tunability from violet (CIE; 0.3380; 0.2162) to light orange (CIE; 0.5666; 0.3408). White light emission from a 1% doped thin film of the complex was realized by changing the excitation wavelength. Thus, the new material could be a potential candidate for the fabrication of full-color display devices and for solid-state lighting (SSL) applications. This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. F.279 Engineering and Physical Sciences Research Council: EP/K004956/1 SR/SQU/SCI/CHEM/16/02 MSK acknowledges His Majesty’s Trust Fund for Strategic Research (Grant No. SR/SQU/SCI/CHEM/16/02) for funding. RI thanks the HM’s Trust Fund for a post-doctoral fellowship. The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDS 2 diffractometer (purchased under grant F.279 of the University Research Fund). PRR is grateful to the Engineering and Physical Sciences Research Council (EPSRC) for continued support (Grant EP/K004956/1).

Two hetero-trinuclear complexes of the type [Eu(btfa)3Pt2-bpy] and [Eu(nta)3Pt2-bpy] (where btfa and nta is the anion of 4,4,4-trifluoro-1-phenyl-1,3-butanedione; 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, respectively and Pt2bpy = trans-[(Ph)(Et3P)2Pt C≡C-R-C≡C Pt(PEt3)2(Ph)] (R = 2,2‘-Bipyridine-6,6‘-diyl) have been synthesized by the reaction between [Eu(β-diketonate)3(H2O)2] (β-diketone = btfa and nta) and Pt2bpy complexes in 1:1 M ratio in THF at room temperature. The complexes have been characterized by analytical and spectroscopic methods. The complexes are soluble in common organic solvents. The photophysical properties of the novel hetero-trinuclear complexes have been analyzed by steady-state and time-resolved emission spectroscopy. The complexes exhibit typical red emission of Eu(III). The absence of any residual ligand emission in the 400–550 nm region clearly attests the efficient energy transfer from the triplet state (T1 = 20,408 cm−1) of Pt2bpy chromophore. The quantum efficiency (ϕEu) of [Eu(btfa)3Pt2-bpy] (ФEu∼53.95%) is 1.88 times higher than [Eu(nta)3Pt2-bpy] (ФEu∼28.63%), which could be due the larger value of the non-radiative decay rate (Anrad) ∼ 1754.41 s−1 for [Eu(nta)3Pt2-bpy] compared to Anrad ∼ 779.24 s−1 for [Eu(btfa)3Pt2-bpy]. Photometric characteristics of the complexes such as color correlated temperature (CCT) and luminous efficiency of the radiation (LER) suggest that the new materials may find potential application in high performance optoelectronic devices.

The title compound, [Cu4Cl6O(C13H9N)4], was obtained by the reaction of CuCl with 4-phenyl­ethynyl­pyridine in di­chloro­methane. The complex contains a tetra­hedron of four CuII cations coordinated to a central μ4-O atom, with the six edges of the Cu4 tetra­hedron bridged by Cl atoms. The Cu—O distances average 1.905 Å and Cu—Cl 2.418 Å., In the crystal structure of the title compound, [Cu4Cl6O(C13H9N)4]·CH2Cl2, the core mol­ecular structure consists of a Cu4 tetra­hedron with a central inter­stitial O atom. Each edge of the Cu4 tetra­hedron is bridged by a chlorido ligand. Each copper(II) cation is coordinated to the central O atom, two chlorido ligands and one N atom of the 4-phenyl­ethynyl­pyridine ligand. In the crystal, the mol­ecules are linked by inter­molecular C—H⋯Cl inter­actions. Furthermore, C—H⋯π and π–π inter­actions also connect the mol­ecules, forming a three-dimensional network. Hirshfeld surface analysis indicates that the most important contributions for the packing arrangement are from H⋯H and C⋯H/H⋯C inter­actions.

Objectives: To examine the current state of practice of oxygen (O2) supplementation in adults hospitalized in a tertiary hospital admitted to medical-surgical floors Methods: We recorded: the propo...

Three highly luminescent Eu(III) complexes of the type [Eu(β-diket.)3(tm-phen)] where β-diket. = hexafluoroacetylacetone (hfaa), btfa; 4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa), 2-thenoyltrifluoroacetone (tta) and tm-phen = 3,4,7,8-tetramethyl-1,10-phenanthroline have been synthesized and characterized. The detailed photophysical properties of the complexes were analyzed both theoretically and experimentally. The theoretical photophysical properties calculated using the LUMPAC program [ 1 ] are in excellent agreement with experimental results. The Judd-Ofelt (J-O) parameters ( Ω 2 and Ω 4 ), radiative (Arad) and non-radiative (Anrad) decay rates were calculated and discussed. Chemical partition of the radiative decay rates (Arad) of electric-dipole transitions revealed that β-diketone contributes 77 to 84% while tm-phen contributes 22 to 16% towards the Arad. The intramolecular energy transfer (WET) and back-energy transfer (WBT) rate are predicted from the singlet (S1) and triplet (T1) levels to the emissive 5D1 and 5D0 states for Eu(III) and follow the path S0 → S1 → T1 → 5D1 → 5D0 → 7F0,4. The complexes emit typical Eu(III) red emission with long luminescence lifetime (0.75–0.88 ms), show high intrinsic quantum yield ( ϕ Ln ) (66–70%) and may be used as one of the red components in light emitting devices.

Two new mixed ligand complexes [Eu(tfac)3(DPEPO)] (Eu-1) and [Tb(tfac)3(DPEPO)] (Tb-2) incorporating trifluoroacetylacetone (Htfac) and bis(2-(diphenylphosphino)phenyl)ether oxide (DPEPO) were synthesized in gram-scale quantities and used as emitters to fabricate single- and double-EML (light-emitting layer) electroluminescence (EL) devices. The single-EML device with the structure: ITO/HAT-CN (6 nm)/HAT-CN (0.2 wt%):TAPC (50 nm)/Eu-1 (1–6 wt%): 26DCzPPy (10 nm)/Tm3PyP26PyB (50 nm)/LiF (1 nm)/Al (100 nm) showed light red (CIE, x: 0.574; y: 0.275) emission for the Eu-1 based EL devices due to the presence of a host emission with a brightness of 1274 cd m−2, current efficiency (ηc), power efficiency (ηp) and external quantum efficiency (EQE) of 0.58 cd A−1, 0.68 lm W−1, and 0.70%, respectively. The single-EML device for the Tb-2 complex with the same device structure displayed white-light emission. The optimized single-EML device of Tb-2 with 14.0 wt% doping concentration showed an impressive EL performance with brightness of 1637 cd m−2, ηc ≈ 3.05 cd A−1, ηp ≈ 2.80 lm W−1, EQE ≈ 1.4%, Vturn-on ≈ 3.1 V, respectively. This is the first report of single component white organic light emitting diode (W-OLED) fabricated from an organo-Tb(III) complex. The W-OLEDs show low turn-on voltages (Vturn-on) ≈ 3.1 V and are thus advantageous in lowering the power consumption of the OLED display.

A new tris β-diketonate europium(III) complex [Eu(btfa)3Py-Im] (Eu-1) (4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa) and 2-(2-pyridyl)benzimidazole (Py-Im)] has been synthesized and structurally characterized. A single crystal X-ray diffraction analysis shows that Eu-1 is octacoordinated and the coordination sphere is composed of a EuO6N2 core with a trigonal dodecahedral (D2d) geometry. The photophysical properties of Eu-1 were analysed in detail and with the help of the experimental PL data and theoretical modelling, energy transfer rates were calculated, and an energy transfer mechanism is proposed for Eu-1. The complex has been used as the emitting layer (EML) to fabricate organic light emitting diodes (OLEDs). Eight OLEDs, of which four single-EML and four double-EML with varying doping concentration, were fabricated via a thermal evaporation method using Eu-1 as the EML. Under the optimum conditions a highly monochromatic bright red emission (CIEx,y = 0.640, 0.311) with brightness (B) = 896 cd/m2, current efficiency (ηc) = 2.26 cd/A, power efficiency (ηp) = 1.92 lm/W and external quantum efficiency (EQE) = 1.6% at very low Vturn-on = 3.4 V was obtained.

Square planar platinum(ii) complexes have been known for 150 years and pincer complexes, supported by a tridentate chelating ligand such as terpyridyl, have been known for more than 70 years. The development of cyclometallated platinum(ii) pincer complexes, in which the tridentate ligand forms one or more platinum-carbon bonds, has been much more recent. Particularly, in terms of their solution and solid-state luminescence these cyclometallated complexes show substantial advantages over their terpyridyl analogues. This tutorial review introduces the reader to the area of platinum(ii) cyclometallated pincer chemistry and shows the advantage of having an alkynyl group in the fourth coordination site on the metal. The basic design principles for the preparation of highly luminescent platinum(ii) cyclometallated pincer complexes are outlined and the strategy to improve the luminescence further by chemical manipulation of the pincer ligand and of the auxiliary ligand in the fourth coordination site are illustrated with recent examples from the literature. Recent applications of these cyclometallated pincer complexes in the area of opto-electronics is described, with emphasis on their use in OLEDs, OFETs and as NLO materials as well as demonstrating their potential use as triplet photosensitizers and as metal ion sensors. The aim of this review is to show the recent advances in this rapidly developing research field and to highlight the future promise of these materials.

Three new iodo-bridged copper(I)complexes of the type [CuI(PPh 3 )L] 2 , where L = Ar–≡–C 5 H 4 N, Ar = phenyl (C 1 ), biphenyl (C 2 )and flourenyl (C 3 )have been synthesized via coordination-driven self-assembly processes. Two of Cu(I)complexes, C 2 and C 3 , have been characterized by single-crystal X-ray diffraction studies. The complexes have two molecules of the P-donor ligand and two molecules of the N-donor ligand in trans configurations, supporting the central Cu 2 I 2 unit. Absorption properties of the complexes have been investigated. Extensive DFT calculation has been carried out to delineate the influence of aromatic spacers on the optical properties and the nature of excited states. The ease of synthesis of these Cu(I)dimers and the wide range of ethynylpyridine supporting ligands that can be incorporated highlights the potential for these materials to form polymers by linking through the ethylylpyridine ligands.

Biodiesel is an eco-friendly renewable fuel that can be derived from microalgae. Maximization of biomass and lipid productivities are considered the main challenges for algal biodiesel production. Since conventional batch cultures are time-, space-, and reagent-consuming with many restrictions to apply many replicates, microfluidic technology has recently emerged as an alternative low-cost and efficient technology with high throughput repeatability and reproducibility. Different applications of microfluidic devices in algal biotechnology have been reported, including cell identification, sorting, trapping, and metabolic screening. In this work, Chlorella vulgaris was investigated by encapsulating in a simple droplet-based micro-array device at different light intensities of 20, 80, and 200 &micro, mol/m2/s combined with different nitrate concentrations of 17.6, 8.8, and 4.4 mM. The growth results for C. vulgaris within microfluidic device were compared to the conventional batch culture method. In addition, the effect of combined stress of deficiencies in irradiance and nitrogen availability were studied to illustrate their impact on the metabolic profiling of microalgae. The results showed that the most optimum favorable culturing conditions for Chlorella vulgaris growth within the microfluidic channels were 17.6 mM and 80 &micro, mol/m2/s.

Two new lanthanide complexes [Ln(hfaa)3(Py-Im)] [hfaa = hexafluoroacetylacetone, Py-Im = 2-(2-pyridyl)benzimidazole and Ln = Eu(III) (1) and Tb(III) (2)] were synthesized and characterized. An X-ra...

Nanopore-based analysis is currently an area of great interest in many disciplines with the potential for exceptionally versatile applications in medicine. This work presents a novel step towards fabrication of a single solid-state nanopore (SSSN) in a thin silicon membrane. Silicon nanopores are realized using multistep processes on both sides of n-type silicon-on-insulator (SOI) &lt, 100&gt, wafer with resistivity 1–4 Ω·cm. An electrochemical HF etch with low current density (0.47 mA/cm2) is employed to produce SSSN. Blue LED is considered to emit light in a narrow band region which facilitates the etching procedure in a unilateral direction. This helps in production of straight nanopores in n-type Si. Additionally, a variety of pore diameters are demonstrated using different HF concentrations. Atomic force microscopy is used to demonstrate the surface morphology of the fabricated pores in non-contact mode. Pore edges exhibit a pronounced rounded shape and can offer high stability to fluidic artificial lipid bilayer to study membrane proteins. Electrochemically-fabricated SSSN has excellent smoothness and potential applications in diagnostics and pharmaceutical research on transmembrane proteins and label free detection.

Copper(I) [Cu(I)] complexes offer cheap and alternative materials for several real-life applications. Pyridine (Py), bipyridine (Bpy), and related analogues have strong donating ability with propensity to ease functionalization via modern synthetic protocols. A large number of Cu(I) complexes/clusters/polymers bearing functionalized Py-based ligands have emerged with rich coordination chemistry, fascinating structures, and intriguing photo-physical properties. This article sheds light on recent advances in the coordination chemistry and photophysical properties of Cu(I) complexes/clusters/polymers and their applications in the areas of optoelectronics (OE) (light emitting devices [LEDs] and dye-sensitized solar cells [DSSCs]) and sensing (aliphatic and aromatic gases).

Nanopore-based technologies are highly adaptable supports for developing label-free sensor chips to characterize lipid bilayers, membrane proteins, and nucleotides. We utilized a single nanopore chip to study the electrophysiology of the epithelial Na+ channel (ENaC) incorporated in supported lipid membrane (SLM). An isolated nanopore was developed inside the silicon cavity followed by fusing large unilamellar vesicles (LUVs) of DPPS (1,2-dipalmitoyl-sn-glycero-3-phosphoserine) and DPPE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine) to produce a solvent-free SLM with giga-ohm (GΩ) sealed impedance. The presence and thickness of SLM on the nanopore chip were confirmed using atomic force spectroscopy. The functionality of SLM with and without ENaC was verified in terms of electrical impedance and capacitance by sweeping the frequency from 0.01 Hz to 100 kHz using electrochemical impedance spectroscopy. The nanopore chip exhibits long-term stability for the lipid bilayer before (144 h) and after (16 h) i...

Supported lipid bilayers (SLBs) are widely used in biophysical research to probe the functionality of biological membranes and to provide diagnoses in high throughput drug screening. Formation of SLBs at below phase transition temperature (Tm) has applications in nano-medicine research where low temperature profiles are required. Herein, we report the successful production of SLBs at above—as well as below—the Tm of the lipids in an anisotropically etched, silicon-based micro-cavity. The Si-based cavity walls exhibit controlled temperature which assist in the quick and stable formation of lipid bilayer membranes. Fusion of large unilamellar vesicles was monitored in real time in an aqueous environment inside the Si cavity using atomic force microscopy (AFM), and the lateral organization of the lipid molecules was characterized until the formation of the SLBs. The stability of SLBs produced was also characterized by recording the electrical resistance and the capacitance using electrochemical impedance spectroscopy (EIS). Analysis was done in the frequency regime of 10−2–105 Hz at a signal voltage of 100 mV and giga-ohm sealed impedance was obtained continuously over four days. Finally, the cantilever tip in AFM was utilized to estimate the bilayer thickness and to calculate the rupture force at the interface of the tip and the SLB. We anticipate that a silicon-based, micron-sized cavity has the potential to produce highly-stable SLBs below their Tm. The membranes inside the Si cavity could last for several days and allow robust characterization using AFM or EIS. This could be an excellent platform for nanomedicine experiments that require low operating temperatures.

Three new tetra-ferrocenylethynylpyridinyl copper complexes, L4(CuI)4 (3), L4(CuBr)2 (4), and L4(CuCl)2 (5) have been prepared from the reaction of ferrocenylethynylpyridine (L)(2) with copper halides CuX (with X = I(-), Br(-), Cl(-)).The ligand 2 and the complexes 3-5 have been fully characterized by spectroscopic methods. The structures of 2-4 have been confirmed by single-crystal X-ray crystallography. 2 forms a dimer in the crystalline-state through C-H··N hydrogen bonds. 4 and 5 are dimers and 3 a tetramer, in all cases linked through Cu-X··Cu bridging interactions. Cyclic voltammetry in dichloroethane showed chemically reversible multiferrocenyl oxidation signals with evidence for product electro-crystallization. The oxidation products were isolated by electrodeposition onto a Pt disc electrode and investigated by scanning electron microscopy which confirmed the spontaneous formation of crystalline oxidation products with distinctive morphologies. Energy dispersive X-ray elemental analysis shows the presence of hexafluorophosphate (counterion) with the P:Fe ratio of 1:1, 0.5:1, and 1:1 for the electrocrystallized products 3, 4, and 5, respectively, suggesting the formulas [3](4+)(PF6(-))4, [4](2+)(PF6(-))2, and [5](4+)(PF6(-))4 for the electro-crystallized products.

Trimethylsilyl-protected dialkynes incorporating azobenzene linker groups, Me3SiC ≡ CRC ≡ CSiMe3 (R = azobenzene-3,3′-diyl, azobenzene-4,4′-diyl, 2,5-dioctylazobenzene-4,4′-diyl), and the corresponding terminal dialkynes, HC ≡ CRC ≡ CH, have been synthesized and characterized. The CuI-catalyzed dehydrohalogenation reaction between trans-[Ph(Et3P)2PtCl] and the deprotected dialkynes in a 2:1 ratio in iPr2NH/CH2Cl2 gives the platinum(II) diynes trans-[Ph(Et3P)2PtC ≡ CRC ≡ CPt(PEt3)2Ph], while the dehydrohalogenation polycondensation reaction between trans-[(nBu3P)2PtCl2] and the dialkynes in a 1:1 molar ratio under similar reaction conditions affords the platinum(II) polyynes, [-Pt(PnBu3)2-C ≡ CRC ≡ C-]n. The materials have been characterized spectroscopically, with the diynes also studied using single-crystal X-ray diffraction. The platinum(II) diynes and polyynes are all soluble in common organic solvents. Optical-absorption measurements show that the compounds incorporating the para-alkynylazobenzene spacers have a higher degree of electronic delocalisation than their meta-alkynylazobenzene counterparts. Reversible photoisomerization in solution was observed spectroscopically for the alkynyl-functionalized azobenzene ligands and, to a lesser extent, for the platinum(II) complexes. Complementary quantum-chemical modeling was also used to analyze the optical properties and isomerization energetics.

Introduction In lung transplantation (LTx), the arterial partial pressure of oxygen (PaO 2 ) is traditionally regarded as critical information for assessment of donor lung function. Each center sets its own thresholds; by convention, a donor PaO 2 of less than 300 mm Hg has been considered disqualifying. Limited literature exists to support such a practice. We analyzed all LTxs performed in the United States over a 9-year period to assess the effect of donor PaO 2 on graft survival. Methods The United Network for Organ Sharing (UNOS) database was queried for LTx (January 2000–November 2009). Of 12,545 LTx performed, 12,045 (96%) had donor PaO 2 data on a fraction of inspired oxygen of 1.0, recorded at the time of procurement. Results Mean donor PaO 2 was 407 ± 140 mm Hg. The majority of LTxs had a donor PaO 2 greater than 300 mm Hg (9593 (80%]) whereas PaO 2 was 200 mm Hg or less in 1830 (15%) and 201 to 300 in 582 (5%) donors. Use of donors with a PaO 2 of less than 200 increased over time from 5% (45) in 2000 to 21% (295) in 2009 ( P = .002). Kaplan-Meier survival analysis showed no difference in graft survival with differing donor PaO 2 s, irrespective of whether patients had a single or double LTx. A Cox multivariable analysis of 21 donor characteristics demonstrated that donor PaO 2 had no association with graft survival. Conclusions Donor PaO 2 levels did not affect graft survival. The use of donors with lower PaO 2 s could substantially increase the donor pool. We are not suggesting that donor PaO 2 is not important when assessing potential lung donors but its level of importance in regard to other criteria appears less than previously believed.

The synthesis and characterization of the thieno[3,2-b]thiophene and dithieno[3,2-b:2′,3′-d]thiophene containing platinum(II) poly-ynes and their molecular precursors is described and the electronic structure is established by absorption, luminescence and photoinduced absorption measurements. A comparison of the electronic structure of the fused and the nonfused oligothiophenes, thieno[3,2-b]thiophene, dithieno[3,2-b:2′,3′-d]thiophene, 2,2′-bithiophene, and 2,2′:5′,2′′-terthiophene incorporated in platinum(II) poly-ynes is reported. We find the singlet S1 and triplet T1 and Tn excited states to be at higher energy in thin films made from the fused systems than from the nonfused systems. For ligands with the same number of rings, we attribute this to the decreased number of double bonds in the fused system and to the presence of an additional sulfur atom in spacers with the same number of double bonds.

The reaction of 2 equiv. of [Os3(CO)10(MeCN)2] with R–C C–L–C C–R (R = H, L = (C4H2S); R = SiMe3, L = (C4H2S–C4H2S), (C4H2S–C4H2S–C4H2S), (C4H2S)–(C14H8)–(C4H2S)) affords the series of linked clusters [{Os3(CO)10}(HC C(C4H2S)C CH){Os3(CO)10}] (1), [{Os3(CO)10}(Me3SiC C(C4H2S–C4H2S)C CSiMe3){Os3(CO)10}] (2), [{Os3(CO)10}(Me3SiC C(C4H2S–C4H2S–C4H2S)C CSiMe3){Os3(CO)10}] (4) and [{Os3(CO)10}(Me3SiC C(C4H2S)–(C14H8)–(C4H2S)C CSiMe3){Os3(CO)10}] (6) as the major products. The complexes have been characterised by a range of spectroscopic methods and, in the case of 1 and 2 by single crystal X-ray crystallography. The alkyne groups cap the osmium triangles in the expected μ3-η2-||-bonding mode and each triangle is coordinated by nine terminal and one μ2-carbonyl group. Solution UV–Vis spectra of the complexes were similar to those observed for the free ligands consistent with there being little delocalisation between the cluster units and the thiophene groups.

Black lipid membranes (BLMs) have been used for detecting single-channel activities of pore-forming peptides and ion channels. However, the short lifetimes and poor mechanical stability of suspended bilayers limit their applications in high throughput electrophysiological experiments. In this work, we present a synthetic solid-state nanopore functionalized with BLM fused with channel protein. A nanopore with diameter of ~180 nm was electrochemically fabricated in a thin silicon membrane. Folding and painting techniques were demonstrated for production of stable suspended BLMs followed by incorporation of transmembrane protein, ENaC. Membrane formation was confirmed by employing electrochemical impedance spectroscopy (EIS) in the frequency regime of 10−2–105 Hz. Results show that electrochemically fabricated solid state nanopore support resulted in excellent membrane stability, with >1 GΩ of up to 72 and 41 h for painting and folding techniques, respectively. After fusion of ENaC channel protein, the BLM exhibits the stability of ~5 h. We anticipate that such a solid-state nanopore with diameter in the range of 150–200 nm and thickness

A series of protected and terminal dialkynes with extended pi-conjugation through a condensed aromatic linker unit in the backbone, 1,4-bis(trimethylsilylethynyl)naphthalene, 1,4-bis(ethynyl)naphthalene, 9,10-bis(trimethylsilylethynyl)anthracene, 9,10-bis(ethynyl)anthracene, have been synthesized and characterized spectroscopically. The solid-state structures of and have been confirmed by single crystal X-ray diffraction studies. Reaction of two equivalents of the complex trans-[Ph(Et(3)P)(2)PtCl] with an equivalent of the terminal dialkynes 1,4-bis(ethynyl)benzene and, in (i)Pr(2)NH-CH(2)Cl(2), in the presence of CuI, at room temperature, afforded the platinum(II) di-ynes trans-[Ph(Et(3)P)(2)Pt-C[triple bond, length as m-dash]C-R-C[triple bond, length as m-dash]C-Pt(PEt(3))(2)Ph](R = benzene-1,4-diyl; naphthalene-1,4-diyl and anthracene-9,10-diyl ) while reactions between equimolar quantities of trans-[((n)Bu(3)P)(2)PtCl(2)] and under similar conditions readily afforded the platinum(II) poly-ynes trans-[-((n)Bu(3)P)(2)Pt-C[triple bond]C-R-C[triple bond]C-](n)(R = naphthalene-1,4-diyl and anthracene-9,10-diyl ). The Pt(II) diynes and poly-ynes have been characterized by analytical and spectroscopic methods, and the single crystal X-ray structures of and have been determined. These structures confirm the trans-square planar geometry at the platinum centres and the linear nature of the molecules. The di-ynes and poly-ynes are soluble in organic solvents and readily cast into thin films. Optical spectroscopic measurements reveal that the electron-rich naphthalene and anthracene spacers create strong donor-acceptor interactions between the Pt(II) centres and conjugated ligands along the rigid backbone of the organometallic polymers. Thermogravimetry shows that the di-ynes possess a somewhat higher thermal stability than the corresponding poly-ynes. Both the Pt(II) di-ynes and the poly-ynes exhibit increasing thermal stability along the series of spacers from phenylene through naphthalene to anthracene.

A new series of rigid rod protected and terminal dialkynes with extended π-conjugation through aromatic and hetero-aromatic linker units in the backbone, 2,5-bis(trimethylsilylethynyl)-1-(2-ethylhexyloxy)-4-methoxybenzene 1a, 2,5-bis(ethynyl)-1-(2-ethylhexyloxy)-4-methoxybenzene 1b, 5,8-bis(trimethylsilylethynyl)quinoline 2a, 5,8-bis(ethynyl)quinoline 2b, 2,3-diphenyl-5,8-bis(trimethylsilylethynyl)quinoxaline 3a, 2,3-diphenyl-5,8-bis(ethynyl)quinoxaline 3b, 4,7-bis(trimethysilylethynyl)-2,1,3-benzothiadiazole 4a and 4,7-bis(ethynyl)-2,1,3-benzothiadiazole 4b, has been synthesised. Treatment of the complex trans-[Pt(Ph)(Cl)(Et3P)2] with half an equivalent of the diterminal alkynes 1b–4b in iPr2NH–CH2Cl2, in the presence of CuI, at room temperature, afforded the platinum(II) di-yne complexes trans-[(Et3P)2(Ph)Pt–CC–R–CC–Pt(Ph)(Et3P)2] [R = 1-(2-ethylhexyloxy)-4-methoxybenzene-2,5-diyl 1c, quninoline-5,8-diyl 2c, 2,3-diphenylquinoxaline-5,8-diyl 3c, 2,1,3-benzothiadiazole-4,7-diyl 4c] in good yields. The new acetylide-functionalised ligands and the platinum(II) σ-acetylide complexes have been characterised by analytical and spectroscopic methods and X-ray single crystal structure determinations for 2c–4c. The absorption spectra of the complexes 2c–4c show substantial donor–acceptor interaction between the platinum(II) centres and the conjugated ligands. The photoluminescence spectra of 1c–3c show characteristic singlet (S1) and triplet (T1) emissions. Both the singlet and triplet emissions as well as the absorption decrease in energy with increasing electronegativity of the spacer groups along the series 1c–4c.

A series of trimethylsilyl-protected and terminal mono- and bis-alkynes based on 9,9-dioctylfluorene, 2-(trimethylsilylethynyl)-9,9-dioctylfluorene 1a, 2-ethynyl-9,9-dioctylfluorene 1b, 2,7-bis(trimethylsilylethynyl)-9,9-dioctylfluorene 2a, 2,7-bis(ethynyl)-9,9-dioctylfluorene 2b, have been synthesised. Reaction of trans-[(PnBu3)2PtCl2] with 2 equivalents of the terminal ethyne 1b yields the mononuclear platinum(II) diyne 3, reaction of trans-[(Ph)(Et3P)2PtCl] with 0.5 equivalents of the diterminal ethyne 2b gives the dinuclear platinum(II) diyne 4 while 1 ∶ 1 reaction between trans-[(PnBu3)2PtCl2] and 2b gives the platinum(II) poly-yne 5. Treatment of 2,5-dioctyloxy-1,4-diiodobenzene with 1b in 1 ∶ 2 stoichiometry produces the organic di-yne 6 while 1 ∶ 1 reaction between 2,5-dioctyloxy-1,4-diiodobenzene and 2b, 2,7-bis(ethynyl)fluorene or 2,7-bis(ethynyl)fluoren-9-one produces the organic co-poly-ynes 7–9. All the new materials have been characterised by analytical and spectroscopic methods and the single crystal X-ray structures of 2a and 3 have been determined. The diynes and poly-ynes are soluble in organic solvents and are readily cast into thin films. Optical spectroscopic measurements reveal that the attachment of octyl side-chains on the fluorenyl spacer reduces inter-chain interaction in the poly-ynes while a fluorenonyl spacer creates a donor–acceptor interaction along the rigid backbone of the organometallic poly-ynes and organic co-poly-ynes.

A series of 1,4-diethynylbenzene (1) derivatives, H-C≡C-R-C≡C-H with R = C6H3NH2 (2), C6H3F (3), C6H2F2-2,5 (4), C6F4 (5), C6H2(OCH3)2-2,5 (6) and C6H2(OnC8H17) 2-2,5 (7) has been synthesised and their crystal structures determined by single crystal (2-5) or powder (6, 7) X-ray diffraction. The C≡CH⋯πC≡=C hydrogen bonds dominating structure 1 are gradually replaced by C≡C-H⋯F ones with the increase of fluorination (3 → 5), or completely replaced by C≡CH⋯N and NH⋯πC≡C bonds in 2, and C≡CH⋯O in 6 and 7. The related platinum-based polymers, trans-[-Pt(PnBu3)2-C≡C-R-C≡C-]) n (R = as above and C6H4,) have been prepared and characterised by spectroscopic methods and thermogravimetry, which show that the amino- and methoxy-derivatives have lowest thermal stability while the fluorinated ones exhibit increasing thermal stability with increasing fluorination. Optical spectroscopic measurements reveal that substituents on the aromatic spacer group do not create strong donor-acceptor interactions along the rigid backbone of the organometallic polymers.

We have studied the evolution of the T1 triplet excited state in an extensive series of phenylene ethynylene polymers and monomers with platinum atoms in the polymer backbone and in an analogous series of all-organic polymers with the platinum(II) tributylphosphonium complex replaced by phenylene. The inclusion of platinum increases spin–orbit coupling so T1 state emission (phosphorescence) is easier to detect. For both, the platinum-containing polymer series and for the all-organic polymers, we find the T1 state to be at a constant separation of 0.7±0.1 eV below the singlet S1 state. It is not possible to change this singlet–triplet splitting by altering the size or the charge-transfer character of the polymer repeat unit or by changing the electron delocalization along the polymer backbone. The S1–T1 gap can be increased by confining the S1 state in oligomers and monomers.

The synthesis and characterisation of a series of novel poly-yne polymers, trans-[–(PnBu3)2Pt(CC–L–CC)-]n (L = 2-(2′-thienyl)-pyridine (L1), 2,5-bis(2′-thienyl)pyridine (L2), 6,6′-bis(2″-thienyl)-3,3′-bipyridine (L3)), and the corresponding platinum dimers trans-[(PEt3)2(Ph)Pt(CCLCC)Pt(Ph)(PEt3)2] are described. The dimers were prepared by the reaction of two equivalents of trans-[Pt(PEt3)2(Ph)Cl] with one equivalent of the diterminal diyne HCC–L–CCH, in CuI catalysed dehydrohalogenation reactions in CH2Cl2–Pri2NH, while the polymers are obtained similarly from the diyne and one equivalent of trans-[Pt(PnBu3)2Cl2]. The optical absorption and photoluminescence spectra of the polymers with L1 and L2 linker groups are reported. The optical gaps are 465 nm (2.67 eV) and 486 nm (2.55 eV), respectively. The photoluminescence spectrum for each polymer exhibits one band at room temperature. At 10 K, low-energy emission bands emerge which are attributed to emission from the triplet excited state. The results of these studies are compared with those obtained for other platinum-containing poly-yne and related organometallic polymers.

A series of trimethylsilyl-protected bis(ethynyl)oligopyridine derivatives Me3SiCC–R–CC–SiMe3 (R = 2,2′-bipyridine-5,5′-diyl (1a), 2,2′-bipyridine-6,6′-diyl (2a), 2,2′:6′,2″-terpyridine-6,6″-diyl (3a), 4′-phenyl-2,2′:6′,2″-terpyridine-6,6″-diyl (4a)) has been synthesised and 2a–4a have been characterised by single crystal X-ray crystallography. The corresponding terminal di-ynes H–CC–R–CCH (1b–4b) and their dinuclear platinum(II) complexes trans-[(Et3P)2(Ph)Pt–CC–R–CC–Pt(Ph)(Et3P)2] (1M–4M) have been characterised spectroscopically and by single-crystal X-ray crystallography for 2M. Novel platinum(II) poly-yne polymers trans-[Pt(PBun3)2–CC–R–CC–]n (1P–4P) containing the oligopyridyl linker groups in the backbone have been synthesised by the CuI-catalysed dehydrohalogenation polycondensation reaction of 1b–4b and trans-[(Bu3P)2PtCl2] in Pri2NH–CH2Cl2. The polymeric materials exhibit decreasing thermal stability with increasing number of pyridine units in the linker group. In the absorption and phosphorescence spectra, the platinum(II) poly-yne and di-yne complexes 1P, 1M show red shifts whereas the complexes 2P–3P, 2M–3M show blue shifts of the S1 and T1 states. At room temperature, the phosphoresence spectra indicate some excimer formation whereas at 10 K, only intra-chain emission occurs. The results of the photophysical studies are compared with those obtained for other platinum(II)-containing poly-ynes and related organometallic polymers.

Three new neutral di-ferrocenyl-ethynylpyridinyl copper complexes, [L2(CuCl)2(PPh3)2] (), [L2(CuBr)2(PPh3)2] (), and [L2(CuI)2(PPh3)2] () were synthesized from the ferrocenyl-ethynylpyridine ligand (L) (), the appropriate copper halide CuX (with X = Cl(-), Br(-), I(-)) and triphenylphosphine. These neutral complexes were fully characterized by spectroscopic methods and by single crystal X-ray crystallography. Cyclic voltammetry in dichloroethane revealed chemically reversible ferrocenyl oxidation signals followed by characteristic "stripping reduction peaks" showing evidence for oxidation-product electro-crystallization. Scanning electron microscopy confirmed spontaneous formation of crystalline oxidation products with three distinct morphologies for X = Cl(-), Br(-), I(-). Energy dispersive X-ray elemental analysis data show Fe : P ratios of 1 : 2.0, 1 : 2.1 and 1 : 2.1 for electro-crystallization products of complexes , , and , respectively, indicating the presence of two [PF6](-) anions in the vicinity of the dioxidized complexes, and suggesting product formulae [](2+)[PF6](-)2, [](2+)[PF6](-)2 and [](2+)[PF6](-)2.

By use of optical steady state and time resolved spectroscopy, we studied the evolution of the triplet excited state in a series of six ethynylenic polymers of the structure [-Pt(PBu3n)2-C≡C-R-C≡C-]n where the spacer unit R is systematically varied to give optical gaps from 1.7–3.0 eV. The inclusion of platinum in the polymer backbone induces a strong spin-orbit coupling such that triplet state emission (phosphorescence) associated with the conjugated system can be detected. Throughout the series we find the S1-T1 (singlet-triplet) energy splitting to be independent of the spacer R, such that the T1 state is always 0.7±0.1 eV below the S1 state. With decreasing optical gap, the intensity and lifetime of the triplet state emission were seen to reduce in accordance with the energy gap law.

The synthesis of a series of metal mono-acetylides trans-[(dppe)2Ru(Cl)(CC–R)] (R=C6H4-p-C6H5, C6H4-p-CH3, C6H4-p-NO2, C6H3-o-CH3-p-NO2, dppe=Ph2PCH2CH2PPh2), and unsymmetrical metal bis-acetylides trans-[(dppm)2M(CC–R)(CC–R′)]; (M=Ru, Os; R=C6H4-p-NO2, R′=C6H5, C6H4-p-CH3; R=C6H5, R′=C6H4-p-CH3) using a variety of σ-acetylide coupling reactions is reported. Three compounds have been structurally characterised, including the unsymmetrical trans-[(dppm)2Os(CC–R)(CC–R′)] (R=C6H4-p-CH3, R′=C6H4-p-NO2] which shows the ‘rigid-rod’ nature of the acetylide-metal-acetylide linkage. The electrochemistry of symmetrical and unsymmetrical Ru(II) complexes demonstrates the role of the acetylide and the auxiliary ligands in determining the ease of oxidation at the metal centre whilst UV–vis spectral changes illustrate the influence of electron-withdrawing and -donating ligands.

A detailed study of the vibrational spectra of the rigid-rod Pt(II)−σ-acetylide polymers, [(PnBu3)2Pt−C⋮CC⋮CC⋮C−]n, [(PnBu3)2Pt−C⋮CC⋮C−]n, [(PnBu3)2Pt−C⋮CC6H4C⋮C−]n, [(PnBu3)2Pt−C⋮CC⋮CC6H4C⋮CC⋮C−]n...

The title compound, C18H20S3Si2, is a precursor in the formation of platinum and gold di-yne complexes and poly-yne polymers. These materials are of interest because of the π-conjugation that extends through the fused oligothienyl linker unit along the rigid backbone of the polymer. In the structure of the title compound, the oligothienyl group is planar and the tri­methyl­silyl­alkyne groups are essentially linear.

The title compound, [Pt2(C6H5)2(C14H6N2)(C6H15P)4], is a dinuclear PtII di-yne complex that exhibits π-conjugation along the molecular backbone. It is used as a model complex for rigid-rod platinum poly-yne polymers of which it is a precursor. Such compounds are of interest because of the extended π-conjugation through the aromatic/heteroaromatic spacer group in the backbone. The asymmetric unit contains two half mol­ecules of the title compound, each lying on a crystallographic centre of symmetry situated at the mid-point of the central C—C bond of the bi­pyridine unit.

The title compound, [Pt2(C6H5)2(C26H36)(C6H15P)4], is a dinuclear PtII di-yne compound exhibiting π-conjugation along the molecular backbone. It is used as a model species for rigid-rod platinum poly-yne compounds of which it is a precursor. Such compounds are of interest due to the extended π-conjugation through the aromatic linker unit in the backbone. In this structure, the mol­ecule lies on an inversion centre such that the asymmetric unit comprises half the formula unit.

The title compound, [Pt(C12H27P)(2)(C14H8N)(2)], is a mononuclear Pt-II di-yne exhibiting pi-conjugation along the molecular backbone. It is used as a model species for rigid-rod platinum poly yne compounds of which it is a precursor. Such compounds are of interest due to the extended pi-conjugation through the hetero-aromatic linker unit in the backbone.

The title compound, [Si(CH3)3(C14H8N)] is a TMS-protected mono-alkyne. It is used as a model species for platinum σ-acetyl­ide compounds of which it is a precursor. Such compounds are of interest due to the extended π-conjugation through the hetero-aromatic linker unit in the backbone.

The complexes trans -[Ru(dppm) 2 (CCPh 2 ] and trans -[Ru(LL) 2 CCRCC] n − [LL = bis-diphenylphosphino)methane (dppm) or bis-(diphenylphosphino)ethane (dppe), R = p -C 6 H 4 or p -C 6 H 2 (CH 3 ) 2 ] have geen prepared by the reaction of the corresponding trans -[Ru(LL) 2 Cl 2 ] compound with Me 3 SnCCPh or Me 3 SnCCRCCSnMe 3 . Reactions between cis -[Ru(LL) 2 Cl 2 ], acetylenes and the salt NaPF 6 have yielded complexes of the type [CI(LL) 2 RuCCPhH] + PF 6 − . These were converted into the corresponding mono-acetylides, [Ru(LL) 2 Cl(CCPh)] by treatment with 1,8-diazabicyclo[5.4. Ojundec-7-ene(DBU) or alumina. Ale single crystal X-ray structure of [Ru(dppe) 2 Cl(CCPh)] confirms that during the reaction of the cis -dihalide species rearrangement takes place to give trans products.

We have carried out measurements of the photovoltaic effect in a platinum-containing poly-yne. A photocell was fabricated with the platinum poly-yne sandwiched between indium-tin oxide (ITO) and aluminium electrodes. A strong photoresponse was seen at the threshold of the singlet exciton absorption near 3.2 eV, with a quantum yield for carrier generation of up to 0.6%. This is comparable to that found in similar devices made with poly(phenylenevinylene) (PPV). It is known that the presence of the platinum atom gives very efficient crossover from singlet to triplet exciton, and we discuss here the effect of triplet excitons on the photogeneration of charge carriers. We also analyse the spectral response of the photocurrent in terms of charge carrier ranges.

We present a comparative study of two isostructural platinum and palladium poly‐ynes, poly[trans(bis(tributylphosphine))M(1,4) phenylenediethynylene], where M represents either platinum or palladium. Optical excitations are associated with the π‐molecular orbitals, and with strong spin–orbit coupling provided by the transition metal, both singlet and triplet excitations can be measured. The platinum and palladium polymers show similar low‐temperature photoluminescence and photoinduced absorption spectra, with a blue‐shift for the palladium polymer of around 5% for electronic transitions with respect to the platinum polymer. For Pt (Pd) we see strong singlet absorption peaks at 3.26 eV (3.49 eV), and weaker triplet absorption peaks at 2.43 eV (≊2.5 eV) at room temperature. Strong photoluminescence from triplet to ground state peaks at 2.38 eV (2.5 eV), and weak photoluminescence from the excited singlet peaks at 3.06 eV (3.2 eV) at low temperatures. Photoinduced absorption that peaks at 1.49 eV (1.72 eV) i...

A series of trimethylsilyl-protected di-alkynes incorporating 3,4-ethylenedioxythiophene (EDOT) linker groups Me3Si–C[triple bond, length as m-dash]C–R–C[triple bond, length as m-dash]C–SiMe3 (R = ethylenedioxythiophene-3,4-diyl 1a, 2,2′-bis-3,4-ethylenedioxythiophene-5,5′-diyl 2a, 2,2′,5′,2′′-ter-3,4-ethylenedioxythiophene-5,5′′-diyl 3a) and the corresponding terminal di-alkynes, H–C[triple bond, length as m-dash]C–R–C[triple bond, length as m-dash]C–H 1b–2b has been synthesized and characterized and the single crystal X-ray structure of 1a has been determined. CuI-catalyzed dehydrohalogenation reaction between trans-[(Ph)(Et3P)2PtCl] and the terminal di-alkynes 1b–2b in iPr2NH/CH2Cl2 (2 : 1 mole ratio) gives the Pt(II) di-ynes trans-[(Et3P)2(Ph)Pt–C[triple bond, length as m-dash]C–R–C[triple bond, length as m-dash]C–Pt(Ph)(Et3P)2] 1M–2M while the dehydrohalogenation polycondensation reaction between trans-[(nBu3P)2PtCl2] and 1b–2b (1 : 1 mole ratio) under similar reaction conditions affords the Pt(II) poly-ynes trans-[Pt(PnBu3)2–C[triple bond, length as m-dash]C–R–C[triple bond, length as m-dash]C-]n1P–2P. The di-ynes and poly-ynes have been characterized spectroscopically and, for 1M and 2M, by single-crystal X-ray which confirms the “rigid rod” di-yne backbone. The materials possess excellent thermal stability, are soluble in common organic solvents and readily cast into thin films. Optical absorption spectroscopic measurements reveal that the EDOT spacers create stronger donor-acceptor interactions between the platinum(II) centres and conjugated ligands along the rigid backbone of the organometallic polymers compared to the related non-fused and fused oligothiophene spacers.

The synthetic utility of bis(trimethylstannyl)alkynyls in the preparation of Group 8 metal (Fe 2+ , Ru 2+ , Os 2+ ) σ-acetylide monomeric, M(DEPE) 2 (CCC 6 H 5 ) 2 (M  Fe 2+ , Ru 2+ ; DEPE = 1,2-bis(diethylphosphino)ethane), Ru(DPPE) 2 (CCC 6 H 5 ) 2 (DPPE = 1,2-bis(diphenylphosphino)ethane), Os(DPPM) 2 (CCC 6 H 5 ) 2 (DPPM = 1,2-bis(diphenylphosphino)methane) and polymeric, [M(DEPE) 2 CCRCC] n (M  Fe 2+ , Ru 2+ ), [Os(DPPM) 2 CCRCC-] n (R = p -C 6 H 4 - C 6 H 4 - p , p -C 6 H 4 , p -C 6 H 2 (CH 3 ) 2 ) complexes is demonstrated. The linear arrangement of the acetylenic units around octahedral metal centres is confirmed by a single crystal X-ray structure determination of the model complex trans -[Ru(DPPE) 2 (CCC 6 H 5 ) 2 ].

Reactions of Me 3 Sn-CC-(CC-) m -CC-SnMe 3 ( m = 0, 1) ( 1 , 2 ), Me 3 Sn-(CC) m - p -C 6 H 4 -(CC) m -SnMe 3 ( m = 1, 2) ( 3 , 4 ) with the platinum metal halide complexes, [Pt(X n Bu 3 ) 2 Cl 2 ] (where X = P ( 5 ), As ( 6 )) afford high molecular weight polymeric species, [-Pt(X n Bu 3 ) 2 -CC-(CC) m -CC-] n ( 7-10 ), and [-Pt(P n Bu 3 ) 2 -(CC) m - p -C 6 H 4 -(CC) m -] n ( 11, 12 ) in excellent yields. Investigations of the optical absorption and photoluminescence spectra of these complexes show extended π-electron conjugation through the metal sites on the chain, with a lower π-π* energy gap for triacetylenic than for the diacetylenic polymeric complexes. Well-resolved vibronic structure associated with the -CC- stretching frequency is observed for both absorption and emission, indicating strong electron-phonon coupling for the di- and triacetylenic polymers.

We investigate the polarization of optical transitions associated with the singlet ${S}_{1}$ and triplet ${T}_{1}$ and ${T}_{n}$ excited states in a uniaxially aligned platinum-containing conjugated polymer which contains a ${2\ensuremath{-}\mathrm{m}\mathrm{e}\mathrm{t}\mathrm{h}\mathrm{o}\mathrm{x}\mathrm{y}\ensuremath{-}5\ensuremath{-}(}^{\ensuremath{'}}$-ethyl)-hexyloxy (MEH)-substituted phenyl ring. For the singlet ${S}_{1}$ state, which is extended along the polymer chain, we find the corresponding absorption and emission to be polarized parallel to the chain as seen for other conjugated polymers. However, for the triplet excited states, we find that the emission from the highly localized ${T}_{1}$ state has components both parallel and perpendicular to the polymer chain, while the absorption from ${T}_{1}$ into the delocalized ${T}_{n}$ state is polarized entirely parallel to the chain. We discuss this connection between the spatial extent of the excited state and the polarization of the associated optical transitions and consider how the spin-orbit coupling mechanism can influence the polarization of emission from the ${T}_{1}$ state.

A new series of Co(II) complexes of the type CoLX 2 , where Lis a tetra-dentate ligand 8,8'-bis(aminomethyl)-2,2'-biquinoline and X= SCN – , BF 4 – , I – or NO 3 – , have been synthesized and characterized. The complexes have magnetic moments in the range typical of a low-spin d 7 Co(II) center. The interaction of these Co(II) complexes with dioxygen was studied by E.S.R. spectroscopy. A dicobalt(III) peroxo-bridged complex was formed in DMF solution, associated with the formation of an E.S.R.-silent solution compatible with the formation of low-spin d 6 Co(III) species. Similar behavior was also observed for the interaction of these Co(II) complexes with dioxygen in the presence of ancillary ligands such as pyridine and 2-methylimidazole. The dioxygen complexes proved successful as oxygen carrier oxidation catalysts for tripehnylphosphine and 2,6-bis( t -butyl)phenol.

2,5-Bis­(tri­methyl­silyl­ethynyl)­thieno­[3,2-b]­thio­phene, C16H20S2Si2, is a tri­methyl­silyl-protected diyne. It is a precursor in the formation of platinum and gold diyne complexes and and polyyne polymers. These materials are of interest because of the π-conjugation that extends through the fused oligothienyl linker unit along the rigid backbone of the polymer. In the structure of the title compound, the oligothienyl group is planar, by crystallographic symmetry, and the tri­methyl­silyl-alkyne groups are essentially linear.