scholarly journals On the Nature of Luminescence Thermochromism of Multinuclear Copper(I) Benzoate Complexes in the Crystalline State

Crystals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 36 ◽  
Author(s):  
Katarzyna Jarzembska ◽  
Michał Hapka ◽  
Radosław Kamiński ◽  
Wojciech Bury ◽  
Sylwia Kutniewska ◽  
...  
Keyword(s):  
Crystalline State ◽  
Crystal Packing ◽  
High Energy ◽  
Theoretical Modelling ◽  
Spectroscopic Techniques ◽  
Structure Property ◽  
Time Resolved ◽  
Structure Property Relationships ◽  
Phosphorescence At Room Temperature ◽  
Metal Charge Transfer

A model luminescent [(PhCO2)4Cu4] (Cu4) complex in the crystalline state was investigated via combined crystallographic and spectroscopic techniques contributed substantially by theoretical modelling. The complex appeared to exhibit luminescence thermochromism, i.e., red phosphorescence at room temperature which changes to green when lowering the temperature to 90 K. The low-energy emissive state was assigned as a cluster-centred triplet, 3CC. The emission from this state predicted in TDDFT (~635 nm) matches the experimental red band observed at 660–715 nm. In contrast, the nature of the high-energy “green” band was less straightforward. The next reached cluster-centred triplet excited state occurred to be energetically close to the experimental value of ~545 nm. The two excited states also exhibit significant metal-to-ligand and ligand-to-metal charge transfer characteristics, especially for solid-state distorted geometries. In both cases the cluster core was expected to become notably contracted when compared to the ground state. Time-resolved photocrystallographic results supported the computationally predicted core contraction upon excitation. Additionally, the differences between the spectroscopic behaviour of the related tetra- and hexanuclear copper(I) complexes, Cu4 and Cu6 (i.e., [(PhCO2)6Cu6]) in the crystalline state were discussed and examined. It appeared that crystal packing may constitute an important factor as far as the lack of luminescence thermochromism in the latter case is concerned. Synopsis: Structure–property relationships characterising a model luminescent [(PhCO2)4Cu4] (Cu4) complex in the crystalline state were investigated via combined crystallographic and spectroscopic techniques contributed by theoretical modelling, and compared with the properties of the related [(PhCO2)6Cu6] (Cu6) complex.

Development of Structure-Property Relationships in Disordered Zirconia Thin Films for High Energy Density Mim Capacitors

2006 ◽  
Vol 969 ◽  
Author(s):  
Guneet Sethi ◽  
Michael T. Lanagan ◽  
Eugene Furman ◽  
Mark W. Horn
Keyword(s):  
Thin Films ◽  
High Energy ◽  
Dc Conductivity ◽  
High Energy Density ◽  
Dielectric Films ◽  
Structure Property ◽  
Gate Oxides ◽  
Low Frequencies ◽  
Structure Property Relationships ◽  
Mim Capacitors

AbstractAmorphous zirconium oxide thin films were prepared by reactive magnetron sputtering. The dielectric films were characterized by impedance spectroscopy with temperature. The effect of annealing on capacitor performance was studied. Annealing gold electroded thin films at 250°C greatly reduced the losses with little changes in crystallinity. Space charge relaxation started to appear at 190°C. The activation energy for the relaxation was 0.84 eV with a very low relaxation frequency at room temperature (0.23μHz). Electrode effects dominated at very low frequencies at all temperatures. AC conductivity followed the universality behavior for the AC charge transport showing that the films are highly disordered. No DC conductivity regime was observed indicating that DC conductivity is very low. DC conductivity of the films was of the order of 10−13 S/m, which is lesser than the comparable thickness high quality gate oxides.

scholarly journals Crystal chemistry and photomechanical behavior of 3,4-dimethoxycinnamic acid: correlation between maximum yield in the solid-state topochemical reaction and cooperative molecular motion

IUCrJ ◽  
2015 ◽  
Vol 2 (6) ◽  
pp. 653-660 ◽  
Author(s):  
Manish Kumar Mishra ◽  
Arijit Mukherjee ◽  
Upadrasta Ramamurty ◽  
Gautam R. Desiraju
Keyword(s):  
Solid State ◽  
Crystal Packing ◽  
Maximum Yield ◽  
Structure Property ◽  
Crystal Forms ◽  
Individual Crystal ◽  
Structure Property Relationships ◽  
Molecular Movement ◽  
Truxillic Acid ◽  
The Individual

A new monoclinic polymorph, form II (P21/c,Z= 4), has been isolated for 3,4-dimethoxycinnamic acid (DMCA). Its solid-state 2 + 2 photoreaction to the corresponding α-truxillic acid is different from that of the first polymorph, the triclinic form I (P\bar 1,Z= 4) that was reported in 1984. The crystal structures of the two forms are rather different. The two polymorphs also exhibit different photomechanical properties. Form I exhibits photosalient behavior but this effect is absent in form II. These properties can be explained on the basis of the crystal packing in the two forms. The nanoindentation technique is used to shed further insights into these structure−property relationships. A faster photoreaction in form I and a higher yield in form II are rationalized on the basis of the mechanical properties of the individual crystal forms. It is suggested that both Schmidt-type and Kaupp-type topochemistry are applicable for the solid-statetrans-cinnamic acid photodimerization reaction. Form I of DMCA is more plastic and seems to react under Kaupp-type conditions with maximum molecular movements. Form II is more brittle, and its interlocked structure seems to favor Schmidt-type topochemistry with minimum molecular movement.

scholarly journals Designing Singlet Fission Candidates from Donor-Acceptor Copolymers

2020 ◽  
Author(s):  
Jacob Terence Blaskovits ◽  
Maria Fumanal ◽  
Sergi Vela ◽  
Clemence Corminboeuf
Keyword(s):  
High Throughput Screening ◽  
Molecular Design ◽  
Crystal Packing ◽  
Cost Effective ◽  
Frontier Molecular Orbital ◽  
Structure Property ◽  
Singlet Fission ◽  
Structure Property Relationships ◽  
Large Databases ◽  
Donor Acceptor

<p>Singlet Fission (SF) has demonstrated significant promise for boosting the power conversion efficiency (PCE) of solar cells. Traditionally, SF is targeted as an intermolecular process, however its dependence on crystal packing makes molecular design difficult. In contrast, intramolecular SF (iSF) enables the exploration of tunable bi-chromophoric systems following well-defined structure-property relationships. In this work, we propose a set of parameters to screen conjugated donor-acceptor copolymer candidates with potential iSF behaviour. We focus our analysis on the E(S<sub>1</sub>)>2E(T<sub>1</sub>) thermodynamic condition and on the appropriate charge transfer (CT) character of S<sub>1</sub>. We map the CT character with respect to the frontier molecular orbital (FMO) energies of the constituent monomers, providing a cost-effective protocol for an accelerated screening of promising iSF donor-acceptor pairs, while minimizing the number of computations. These parameters are applied to a chemically diverse, curated library of 81 truncated dimers of synthetically feasible donor-acceptor copolymers. From our dataset, four candidates are flagged for iSF, two of which were previously experimentally reported. This protocol is envisioned to be scaled up for the high-throughput screening of large databases of donor-acceptor dimers for the design and identification of conjugated polymers capable of iSF. </p>

scholarly journals Nanocrystalline diamond (NCD): an insight into structure-property relationships

2014 ◽  
Vol 70 (a1) ◽  
pp. C1334-C1334
Author(s):  
Natalia Dubrovinskaia ◽  
Leonid Dubrovinsky ◽  
Natalia Solopova ◽  
Artem Abakumov ◽  
Anatoly Snigirev ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Polycrystalline Diamond ◽  
High Energy ◽  
Nanocrystalline Diamond ◽  
High Yield ◽  
Structure Property ◽  
X Ray ◽  
Structure Property Relationships ◽  
Single Crystal Diamond ◽  
Insight Into

Nanocrystalline diamond (NCD) is a unique material we produce by direct conversion of glassy carbon into diamond at ca. 20 GPa and 2200 K in a multi anvil press. One of precursor materials we use is commercially available in the form of glassy carbon balls with a diameter of 20 to 50 microns. NCD demonstrates superior mechanical properties (e.g. extremely high yield strength under confining pressure) and has been successfully used for ultra-high static pressure generation (above 600 GPa) in a double-stage diamond anvil cell (DAC) (Ref. 1). To elucidate structure-property relationships in this extremely strong and seemingly inscrutable material we have investigated its microstructure using HRTEM and HAADF-STEM, measured its compressibility by means of synchrotron X-ray diffraction in a DAC, and evaluated its hardness in comparison to that of the hardest known materials - single-crystal diamond and nano-polycrystalline diamond (NPD) (Ref. 2). An additional insight into the volume compressibility was obtained due to X-ray phase contrast micro-imaging using a coherent high-energy synchrotron radiation. The established structure-property relationships will be presented and analyzed.

New Second-Order Nonlinear Optical Organic Crystals

1989 ◽  
Vol 173 ◽  
Author(s):  
D.S. Donald ◽  
L.-T. Cheng ◽  
G. Desiraju ◽  
G. R. Meredith ◽  
F. C. Zumsteg
Keyword(s):  
Nonlinear Optical ◽  
Near Infrared ◽  
Crystal Packing ◽  
Screening Program ◽  
Molecular Crystals ◽  
Molecular Properties ◽  
Organic Crystals ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Near Ultraviolet

ABSTRACTThe design of molecular crystals with specific optical properties, which are thought to arise from constituent molecules’ polarizability properties, is a desirable but currently unachievable goal. One can partially achieve this goal by choosing compounds with specific molecular attributes and empirically determining the manner in which these are translated into crystal properties. Besides the fact that there are no certain rules for prediction of crystal packing arrangements, there is also a problem in specifying molecular properties from what are today incomplete polarizability structure-property relationships. We have, realizing these limitations, identified new molecular crystals by a nonlinear optical (powder-SHG) scouting-screening program from lists of compounds chosen because of desirable molecular properties. Examination of successful materials has revealed interesting, new alignment motifs. Some of these materials, a set of halogen and cyano derivatives of aromatic compounds, are described relating properties and structures of molecules and crystals. In particular, the orientation directing influence of intermolecular halogen-cyano interactions and the use of heterocyclic compounds to improve transparency in the near infrared and in the blue and near ultraviolet spectral regions are demonstrated.

scholarly journals Dynamic transformation of cubic copper catalysts during CO2 electroreduction and its impact on catalytic selectivity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Philipp Grosse ◽  
Aram Yoon ◽  
Clara Rettenmaier ◽  
Antonia Herzog ◽  
See Wee Chee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Copper Catalysts ◽  
Underlying Structure ◽  
Structure Property ◽  
Product Analysis ◽  
Time Resolved ◽  
Catalytic Selectivity ◽  
Structure Property Relationships ◽  
Co2 Electroreduction ◽  
The Impact

AbstractTo rationally design effective and stable catalysts for energy conversion applications, we need to understand how they transform under reaction conditions and reveal their underlying structure-property relationships. This is especially important for catalysts used in the electroreduction of carbon dioxide where product selectivity is sensitive to catalyst structure. Here, we present real-time electrochemical liquid cell transmission electron microscopy studies showing the restructuring of copper(I) oxide cubes during reaction. Fragmentation of the solid cubes, re-deposition of new nanoparticles, catalyst detachment and catalyst aggregation are observed as a function of the applied potential and time. Using cubes with different initial sizes and loading, we further correlate this dynamic morphology with the catalytic selectivity through time-resolved scanning electron microscopy measurements and product analysis. These comparative studies reveal the impact of nanoparticle re-deposition and detachment on the catalyst reactivity, and how the increased surface metal loading created by re-deposited nanoparticles can lead to enhanced C2+ selectivity and stability.

scholarly journals Designing Singlet Fission Candidates from Donor-Acceptor Copolymers

2020 ◽  
Author(s):  
Jacob Terence Blaskovits ◽  
Maria Fumanal ◽  
Sergi Vela ◽  
Clemence Corminboeuf
Keyword(s):  
High Throughput Screening ◽  
Molecular Design ◽  
Crystal Packing ◽  
Cost Effective ◽  
Frontier Molecular Orbital ◽  
Structure Property ◽  
Singlet Fission ◽  
Structure Property Relationships ◽  
Large Databases ◽  
Donor Acceptor

<p>Singlet Fission (SF) has demonstrated significant promise for boosting the power conversion efficiency (PCE) of solar cells. Traditionally, SF is targeted as an intermolecular process, however its dependence on crystal packing makes molecular design difficult. In contrast, intramolecular SF (iSF) enables the exploration of tunable bi-chromophoric systems following well-defined structure-property relationships. In this work, we propose a set of parameters to screen conjugated donor-acceptor copolymer candidates with potential iSF behaviour. We focus our analysis on the E(S<sub>1</sub>)>2E(T<sub>1</sub>) thermodynamic condition and on the appropriate charge transfer (CT) character of S<sub>1</sub>. We map the CT character with respect to the frontier molecular orbital (FMO) energies of the constituent monomers, providing a cost-effective protocol for an accelerated screening of promising iSF donor-acceptor pairs, while minimizing the number of computations. These parameters are applied to a chemically diverse, curated library of 81 truncated dimers of synthetically feasible donor-acceptor copolymers. From our dataset, four candidates are flagged for iSF, two of which were previously experimentally reported. This protocol is envisioned to be scaled up for the high-throughput screening of large databases of donor-acceptor dimers for the design and identification of conjugated polymers capable of iSF. </p>

Mechanical Structure-Property Relationships of Microcellular, Low Density Foams.

1990 ◽  
Vol 207 ◽  
Author(s):  
James D. Lemay
Keyword(s):  
Mechanical Properties ◽  
High Energy Physics ◽  
High Energy ◽  
Department Of Energy ◽  
Low Density ◽  
Foam Density ◽  
Structure Property ◽  
Microcellular Foams ◽  
Structure Property Relationships ◽  
Energy Physics

AbstractHigh energy physics applications at the Department of Energy National Laboratories require unique low-density foams of demanding homogeneity specifications (cell sizes on the order of 10 μm or smaller). These delicate and fragile foams are machined and shaped into specimens to exacting tolerances. In this work, the mechanical properties of a variety of these low density microcellular foams are reported as functions of foam density and morphology.

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