The synthesis and structural, photophysical, electrochemical, and electroluminescent properties of a class of platinum(II) complexes bearing σ-alkynyl ancillary ligands, namely [(C∧N∧N)Pt(C⋮C)nR] [H(C∧N∧N) = 6-aryl-2,2‘-bipyridine; n = 1−4; R = aryl, alkyl, or trimethylsilyl], have been studied. Substituents with different steric and electronic properties were introduced into the tridentate cyclometalating and arylacetylide ligands, and the π-conjugation length of the oligoynyl moiety was homologously extended from ethynyl to octatetraynyl. The X-ray crystal structures of several derivatives confirm the Pt−(C⋮C) ligation and reveal various intermolecular interactions, such as π−π, Pt···Pt, and C−H···F−C. The complexes display good thermal stability and intense phosphorescence in fluid and glassy solutions with high quantum yields and microsecond lifetimes. Their emission energies are sensitive to solvent polarity, the electronic affinities of the substituents on both the cyclometalating and arylacetylide ...

Light-Emitting Tridentate Cyclometalated Platinum(II) Complexes Containing σ-Alkynyl Auxiliaries: Tuning of Photo- and Electrophosphorescence

Carbon in one dimension: structural analysis of the higher conjugated polyynes.

With the Fritsch−Buttenberg−Wiechell rearrangement as a primary synthetic route, a series of conjugated, triisopropylsilyl end-capped polyynes containing 2−10 acetylene units has been assembled. In a few steps, significant quantities of the polyynes are made available, which allow for a thorough analysis of their structural, physical, and optical properties. Molecules in the series have been characterized in detail using 13C NMR spectroscopy, differential scanning calorimetry, mass spectrometry, and, for four derivatives including octayne 6, X-ray crystallography. UV−vis spectroscopy of the polyynes 1−7 shows a consistent lowering of the HOMO−LUMO gap (Eg) as a function of the number of acetylene units (n), fitting a power-law relationship of Eg ∼ n-0.379±0.002. The third-order nonlinear optical (NLO) properties of the polyyne series have been examined, and the nonresonant molecular second hyperpolarizabilities (γ) increase as a function of length according to the power-law γ ∼ n4.28±0.13. This result exh...

http://www.aaronslepkov.com/docs/Eisler%20et%20al,%20JACS%20127%202666%202005.pdf

Polyynes as a model for carbyne: synthesis, physical properties, and nonlinear optical response.

The field of electronics using single-molecule components has recently received much attention as a possible new design concept for the continued miniturisation of electronics. Molecular wires are the conceptually simplest components of such electronic systems and several different compound types have been used to produce molecular wires. Examples of some of the most promising families of molecular wires are presented, namely conjugated hydrocarbons, carbon nanotubes, porphyrin oligomers and DNA. Discussion centres around their potential use in functioning electronic architectures in terms of their electronic properties, ease and controllability of synthesis and potential for self-assembly.

A comparison of potential molecular wires as components for molecular electronics.

Coordination and organometallic chemistry of metal-NO complexes.

Reaction of the butadiynyl complex (η5-C5Me5)Re(NO)(PPh3)(C⋮CC⋮CH) (ReC4H) with Cu(OAc)2 (pyridine, 80 °C) gives the μ-octatetraynediyl complex ReC8Re (70%). Analogous cross-coupling of ReC4H and ReC2H gives (after chromatography) ReC4Re (14%), ReC6Re (44%), and ReC8Re (15%). Longer sp carbon chains are accessed by reactions of ReC4H with n-BuLi and CuI, which give ReC4Cu. This isolable species is treated in situ with BrC⋮CSiEt3 or BrC⋮CC⋮CSiMe3 (excess EtNH2, THF) to give ReC6SiEt3 or ReC8SiMe3 (84−77%). Desilylations (wet n-Bu4N+F-) yield ReC6H or ReC8H (88−73%). Then Cu(OAc)2 (pyridine, 50 °C) gives ReC12Re or ReC16Re (71−67%). The former is also available from ReC4Cu and BrC⋮CC⋮CBr (45%), and ReC10Re can be accessed by cross-coupling. ReC6H and ReC8H are similarly converted to ReC10SiR3 (R = Me, Et; 51−26%) and ReC12SiMe3 (43%). Desilylation of ReC10SiR3 gives labile ReC10H, but only black powder is obtained from ReC12SiMe3. In situ coupling of ReC10H gives ReC20Re (52−34%), which unlike lower homolog...

Toward Metal-Capped One-Dimensional Carbon Allotropes: Wirelike C6−C20 Polyynediyl Chains That Span Two Redox-Active (η5-C5Me5)Re(NO)(PPh3) Endgroups

Experimental Investigation on the Methanation of Hydrogen-Rich Syngas in a Bubbling Fluidized Bed Reactor Utilizing an Optimized Catalyst

Dynamic modeling of dual fluidized bed steam gasification for control design

Digital reflections of physical energy plants can help support and optimize energy technologies within their lifecycle. So far, no framework for the evolution of virtual representations throughout the process development lifecycle exists. Based on various concepts of virtual representations in different industries, this review paper focuses on developing a novel virtual representation framework for the process development environment within the energy sector. The proposed methodology enables the continuous evolution of virtual representations along the process development lifecycle. A novel definition for virtual representations in the process development environment is developed. Additionally, the most important virtual representation challenges, properties, and applications for developing a widely applicable framework are summarized. The essential sustainability indicators for the energy sector are listed to standardize the process evaluation throughout the process development lifecycle. The virtual representation and physical facility development can be synchronized by introducing a novel model readiness level. All these thoughts are covered through the novel virtual representation framework. Finally, the digital twin of a Bio-SNG production route is presented, to show the benefits of the methodology through a use case. This methodology helps to accelerate and monitor energy technology developments through the early implementation of virtual representations.

/pdf/methodology-for-the-development-of-virtual-representations-2actww8i.pdf

Methodology for the Development of Virtual Representations within the Process Development Framework of Energy Plants: From Digital Model to Digital Predictive Twin—A Review

Abstract Chemical looping combustion is a highly efficient CO 2 separation technology without direct contact between combustion air and fuel. A metal oxide is used as an oxygen carrier in dual fluidized beds to generate clean CO 2 . The use of biomass is the focus of current research because of the possibility of negative CO 2 emissions and the utilization of biogenic carbon. The most commonly proposed OC are natural ores and residues, but complete combustion has not yet been achieved. In this work, the direct utilization of CLC exhaust gas for methane synthesis as an alternative route was investigated, where the gas components CO, CH 4 and H 2 are not disadvantageous but benefit the reactions in a methanation step. The whole process chain, the coupling of an 80 kW th pilot plant with gas cleaning and a 10 kW fluidized bed methanation unit were for this purpose established. As OC, ilmenite enhanced with limestone was used, combusting bark pellets in autothermal operation at over 1000 °C reaching high combustion efficiencies of up to 91.7%. The fuel reactor exhaust gas was mixed with hydrogen in the methanation reactor at 360 °C and converted with a methane yield of up to 97.3%. The study showed especially high carbon utilization efficiencies of 97% compared to competitor technologies. Based on the experimental results, a scale-up concept study showed the high potential of the combination of the technologies concerning the total efficiency and the adaptability to grid injection. Graphical Abstract 

/pdf/experimental-demonstration-of-80-kwth-chemical-looping-3ftzphrl.pdf

a Tamás Bartik

Papers

Toward Metal-Capped One-Dimensional Carbon Allotropes: Wirelike C6−C20 Polyynediyl Chains That Span Two Redox-Active (η5-C5Me5)Re(NO)(PPh3) Endgroups

Experimental Investigation on the Methanation of Hydrogen-Rich Syngas in a Bubbling Fluidized Bed Reactor Utilizing an Optimized Catalyst

Dynamic modeling of dual fluidized bed steam gasification for control design

Methodology for the Development of Virtual Representations within the Process Development Framework of Energy Plants: From Digital Model to Digital Predictive Twin—A Review

Experimental demonstration of 80 kWth chemical looping combustion of biogenic feedstock coupled with direct CO2 utilization by exhaust gas methanation