Unsolvated Al(C6F5)3: structural features and electronic interaction with ferrocene

2016 ◽  
Vol 45 (14) ◽  
pp. 6105-6110 ◽  
Author(s):  
Jiawei Chen ◽  
Eugene Y.-X. Chen

The unsolvated Al(C6F5)3exists as a dimer in the solid stateviadouble Al⋯(ortho-)F bridging and forms a stable adduct with Cp2Fe through η1-coordination.

1998 ◽  
Vol 62 (5) ◽  
pp. 581-583
Author(s):  
Simon A. T. Redfern

How can the equilibrium and non-equilibrium thermodynamics of minerals be understood from their atomic-scale structural features? How can they be predicted, simply from models for the forces between atoms? Advances in analytical theory, statistical mechanics, experimental solid-state science, computational power, and the sophistication of a mineralogical approach that brings all of these together, means that these questions, once imponderable, are now realistically tractable. These questions have been exercising the minds of mineralogists over the last decade or so, and have motivated many developments in the science. Acting as way-markers along the path, there are a number of publications which have followed from meetings where these questions have been addressed. It is now twelve years since the publication of Microscopic to Macroscopic, an edition of Reviews in Mineralogy (Kieffer and Navrotsky, 1985) that sought to identify the fundamental controls on the bulk properties of minerals in terms of their atomic-scale characteristics.


2017 ◽  
Vol 70 (11) ◽  
pp. 1227 ◽  
Author(s):  
Carol Hua ◽  
Stone Woo ◽  
Aditya Rawal ◽  
Floriana Tuna ◽  
James M. Hook ◽  
...  

A series of electroactive triarylamine porous organic polymers (POPs) with furan, thiophene, and selenophene (POP-O, POP-S, and POP-Se) linkers have been synthesised and their electronic and spectroscopic properties investigated as a function of redox state. Solid state NMR provided insight into the structural features of the POPs, while in situ solid state Vis-NIR and electron paramagnetic resonance spectroelectrochemistry showed that the distinct redox states in POP-S could be reversibly accessed. The development of redox-active porous organic polymers with heterocyclic linkers affords their potential application as stimuli responsive materials in gas storage, catalysis, and as electrochromic materials.


2012 ◽  
Vol 730-732 ◽  
pp. 715-720
Author(s):  
Telmo G. Santos ◽  
João Faria ◽  
Pedro Vilaça ◽  
R.M. Miranda

Eddy currents are based on electromagnetic induction and analysis of electrical currents on conductive materials. This method is used for thickness measurements, corrosion and defects detection, electrical conductivity and magnetic permeability measurements. Recently, it has been exploited as a materials characterization technique, namely in solid state welding, since, compared to hardness, it is based in distinct physical phenomena. Electrical conductivity is controlled by electronic mobility, while hardness depends on crystal defects and thus a scale factor exists. This paper presents results of this characterization technique applied to multipass solid state friction stir processing (FSP) of AA1100 alloy. These results were compared to microstructural analysis and hardness measurements and show that eddy current is a feasibly, reliable and expedite technique to characterize processed materials. The electrical conductivity measured by eddy currents, maps more precisely structural features, while hardness does not. Measurement of electrical conductivity field suggests having potential to constitute an alternative and/or complement to hardness evaluation with the further advantage of being a non-destructive method.


2020 ◽  
Author(s):  
Jeongjae Lee ◽  
Woocheol Lee ◽  
Keehoon Kang ◽  
Takhee Lee ◽  
Sung Keun Lee

Application of two-dimensional (2D) organic-inorganic hybrid halide perovskites for optoelectronic devices requires detailed understanding of the local structural features including the Pb-I bonding in the 2D layers and the capping ligand-perovskite interaction. In this study, we show that <sup>1</sup>H and <sup>207</sup>Pb solid-state Nuclear Magnetic Resonance (NMR) spectroscopy can serve as a non-invasive and complementary technique to quantify the composition and to probe the local structural features of 2D Ruddlesden-Popper phase BA<sub>2</sub>MA<i><sub>n</sub></i><sub>-1</sub>Pb<i><sub>n</sub></i>I<sub>3<i>n</i>+1</sub> (<i>n</i>=1-4) with butylammonium (BA) spacers. <sup>207</sup>Pb echo and <sup>1</sup>H-detected <sup>207</sup>Pb→<sup>1</sup>H heteronuclear correlation (HETCOR) experiments enables layer-by-layer structural detection of 2D halide perovskites. We show that the observed correlation between <sup>207</sup>Pb NMR shifts and mean Pb-I bond lengths around each Pb site allows us to probe the local bonding environment of Pb via its <sup>207</sup>Pb NMR shift. We envisage that this technique will be vital for better understanding the materials properties as determined by the local atomistic environments in multi-dimensional halide perovskites.


2004 ◽  
Vol 814 ◽  
Author(s):  
H. Detert ◽  
O. Sadovski ◽  
Erli Sugiono

AbstractThe fourfold Horner olefination of tetraphenylmethane or –silane with fourp-methyl- phosphonate groups and a variety of aromatic aldehydes with donor groups or extended conjugated systems results in the formation of tetrahedra from four chromophores connected via a central atom. Electronic spectra in solution reveal an electronic interaction between the π-systems. In the solid state, the emission of compounds with a dense packing is nearly identical to the solution spectra, more open structures show significant red shifts. The emission of scaffolds with 1-styrylpyrene chromophores is nearly completely quenched. Most of these tetrahedra are thermally stable up to 420°C. Depending on the diameter of the scaffold, glass transitions occur between 99°C and 169°C.


NANO ◽  
2019 ◽  
Vol 14 (03) ◽  
pp. 1950030 ◽  
Author(s):  
Man Zhang ◽  
Yanwei Sui ◽  
Xiaofang Yuan ◽  
Jiqiu Qi ◽  
Fuxiang Wei ◽  
...  

A nanoflower structure of Zn[Formula: see text]Co[Formula: see text]S directly grown on carbon fiber papers (CFP) was successfully designed by a mild two-step hydrothermal method. Benefiting from their fascinating structural features, Zn[Formula: see text]Co[Formula: see text]S/CFP electrode exhibits a maximum specific capacitance of 300[Formula: see text]F[Formula: see text]g[Formula: see text] at current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text] and 84% capacitance retention after 5,000 cycles at current density of 5[Formula: see text]A[Formula: see text]g[Formula: see text]. Subsequently, Zn[Formula: see text]Co[Formula: see text]S/CFP//AC all-solid-state asymmetric supercapacitor (ASC) device is assembled and able to illuminate the red LEDs. ASC devices deliver a maximum energy density of 9.59[Formula: see text]W[Formula: see text]h[Formula: see text]kg[Formula: see text] at a power density of 750[Formula: see text]W[Formula: see text]kg[Formula: see text]. Therefore, this impressive result demonstrates that the nanoflower Zn[Formula: see text]Co[Formula: see text]S have promising applications in the development of high-performance supercapacitors.


1997 ◽  
Vol 53 (2) ◽  
pp. 293-299 ◽  
Author(s):  
T. Y. Fu ◽  
Z. Liu ◽  
G. Olovsson ◽  
J. R. Scheffer ◽  
J. Trotter

Inclusion complexes of 9,10-dihydro-9,10-etheno-anthracene-11,12-bis(diphenylphosphine oxide) (1) as host are synthesized using a variety of guest solvent molecules and the photochemistry of the host molecule is studied in solution and in the crystalline complexes. The crystal structures of four complexes are determined and correlated with their photochemical reactivity. In each case only one dibenzosemibullvalene photoproduct is obtained in the photolysis. Since three of the complexes studied crystallize in the chiral space group P212121, irradiation of single crystals produces a chiral photoproduct in >90% enantiomeric excess. Determination of the absolute configurations of reactants and products allows elucidation of the key structural features that control the enantiospecific solid-state photorearrangements.


2000 ◽  
Vol 56 (2) ◽  
pp. 210-214
Author(s):  
Thomas E. Concolino ◽  
Kin-Chung Lam ◽  
Ilia A. Guzei ◽  
Arnold L. Rheingold ◽  
Gerd W. Rabe

The solvent-bridged caesium phosphide {[CsPH(η 6-2,4,6- t Bu3C6H2)]2(η 3-toluene)0.5} x , catena-[(μ-η3-toluene)-bis[caesium(2,4,6-tri-tert-butylphenylphosphide)]], undergoes a reversible solid-state, order–disorder phase transition characterized by the doubling of the unit-cell volume at low temperature achieved by doubling one unit-cell vector. The unit-cell parameters at 293 (2) K (form A) are: a = 11.147 (4), b = 14.615 (4), c = 14.806 (5) Å, α = 70.57 (3), β = 71.85 (3), γ = 72.93 (2)°, V = 2112.5 (12) Å3, Z = 2, ρcalc = 1.362 g cm−3, R 1 = 0.0513 for 5462 reflections, wR 2 = 0.0947 for all data. The unit-cell parameters at 173 (2) K (form B) are: a = 14.6241 (3), b = 14.7393 (3), c = 22.0720 (4) Å, α = 72.2117 (7), β = 73.3659 (8), γ = 70.2953 (7)°, V = 4174.8 (2) Å3, Z = 4, ρcalc = 1.379 g cm−3, R 1 = 0.0405 for 14 010 reflections, wR 2 = 0.1326 for all data. With a minor change, the key structural features discussed previously for form A [Rabe et al. (1998). Inorg. Chem. 37, 4235–4245] remain unchanged. The η 3-toluene ligand is observed to be disordered at 293 (2) K and ordered at 173 (2) K, with the order–disorder phase transition occurring at approximately 278 (2) K.


2012 ◽  
Vol 65 (10) ◽  
pp. 1361 ◽  
Author(s):  
Roger Bishop

Intermolecular attractive forces that are considerably weaker than hydrogen bonding and coordination complexation may be used in the design of new molecules that function as host molecules in the solid-state. Known literature examples of accidentally discovered hosts (clathrands), which do not involve strong interactions in their crystals, are identified and discussed. Their molecular symmetry and supramolecular interactions are analysed in order to identify structural features that facilitate and promote molecular inclusion. The solid-state properties of a family of designed compounds that embody these principles are then described. Prediction of their inclusion behaviour was 95 % successful and a wide variety of crystal packing arrangements were encountered. This is an inevitable consequence of competition between many different molecular interactions of comparable energy during the crystallisation process. The lowest energy combination of these host–host and host–guest associations generates the observed outcome. One consequence of this behaviour is that detailed prediction of a new clathrate crystal packing arrangement is extremely difficult. However, a second consequence is that crystal structure analysis provides a rich source of information about weak intermolecular forces and new supramolecular synthons that previously had remained hidden.


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