scholarly journals Alkaline Earth Complexes of a Sterically Demanding Guanidinate Ligand

2015 ◽  
Vol 2015 (36) ◽  
pp. 5892-5902 ◽  
Author(s):  
Graeme J. Moxey ◽  
Alexander J. Blake ◽  
William Lewis ◽  
Deborah L. Kays
Keyword(s):  
Alkaline Earth ◽  
Sterically Demanding ◽  
Guanidinate Ligand

scholarly journals From Neutral to Ionic Species: Studies of Li...P(SiMe3)-PtBu2Complexes

2014 ◽  
Vol 70 (a1) ◽  
pp. C640-C640
Author(s):  
Petra Bombicz ◽  
Ewald Sattler ◽  
Ilona Kovács ◽  
Alexander Rothenberger ◽  
Alexander Okrut
Keyword(s):  
Coordination Number ◽  
Transition Metal Complexes ◽  
Alkaline Earth ◽  
Building Blocks ◽  
Ionic Species ◽  
Fine Tuning ◽  
Clear Correlation ◽  
Coordination Numbers ◽  
Sterically Demanding ◽  
Ring Structures

The alkali and alkaline earth phosphanides have already been intensively studied, nonetheless there are only a few reports on the alkali metal diphosphanides, on their structural properties and their synthetic use as building blocks for the synthesis of phosphorus-rich compounds and, in particular, transition- metal complexes. This study extends the so far small family of lithium diphosphanides with the series of Li(L)nP-(SiMe3)-PtBu2, where L = THF, n = 0–3; L = TMEDA or 12-crown-4, n = 2. The coordination numbers of the Li ions are in the range of two to eight in the investigated compounds. There is a clear correlation between the Li-P distance and the coordination number of the Li atom. The higher the coordination number of the Li atom, the longer the Li–P distance is. Coordination numbers of four or higher lead to ionic structures. The influence of the space requirement of the phosphorus substituents on the Li-P bond length should also be taken into account especially in the case of coordination number two. Eight-membered ring structures are realized when the formation of four-membered rings is prevented by sterically demanding substituents. This work is a contribution to the fine tuning of structures by donor molecules and substituents [1].

THERMOLUMINESCENCE IN ALKALINE-EARTH DOPED KCl IRRADIATED AT ROOM TEMPERATURE

1976 ◽  
Vol 37 (C7) ◽  
pp. C7-158-C7-158
Author(s):  
A. RASCÓN ◽  
J. L. ALVAREZ RIVAS
Keyword(s):  
Alkaline Earth ◽  
Room Temperature

Regioselective Gas-Phase n-Butane Transfer Dehydrogenation via Silica-Supported Pincer-Iridium Complexes

2020 ◽  
Author(s):  
Boris Sheludko ◽  
Cristina Castro ◽  
Chaitanya Khalap ◽  
Thomas Emge ◽  
Alan Goldman ◽  
...  
Keyword(s):  
Gas Phase ◽  
Active Site ◽  
Lower Cost ◽  
Open Systems ◽  
Iridium Complexes ◽  
Terminal Olefin ◽  
Molecular Precursors ◽  
Sterically Demanding ◽  
Olefin Production ◽  
Steam Cracking

<b>Abstract:</b> The production of olefins via on-purpose dehydrogenation of alkanes allows for a more efficient, selective and lower cost alternative to processes such as steam cracking. Silica-supported pincer-iridium complexes of the form [(≡SiO-<sup>R4</sup>POCOP)Ir(CO)] (<sup>R4</sup>POCOP = κ<sup>3</sup>-C<sub>6</sub>H<sub>3</sub>-2,6-(OPR<sub>2</sub>)<sub>2</sub>) are effective for acceptorless alkane dehydrogenation, and have been shown stable up to 300 °C. However, while solution-phase analogues of such species have demonstrated high regioselectivity for terminal olefin production under transfer dehydrogenation conditions at or below 240 °C, in open systems at 300 °C, regioselectivity under acceptorless dehydrogenation conditions is consistently low. In this work, complexes <a>[(≡SiO-<i><sup>t</sup></i><sup>Bu4</sup>POCOP)Ir(CO)] </a>(<b>1</b>) and [(≡SiO-<i><sup>i</sup></i><sup>Pr4</sup>PCP)Ir(CO)] (<b>2</b>) were synthesized via immobilization of molecular precursors. These complexes were used for gas-phase butane transfer dehydrogenation using increasingly sterically demanding olefins, resulting in observed selectivities of up to 77%. The results indicate that the active site is conserved upon immobilization.

Impact of Alkaline Earth Metal Doping on the Stability of Perovskite Solar Cells

2019 ◽  
Author(s):  
Nga Phung ◽  
Hans Köbler ◽  
Diego Di Girolamo ◽  
Thi Tuyen Ngo ◽  
Gabrielle Sousa e Silva ◽  
...  
Keyword(s):  
Solar Cells ◽  
Alkaline Earth ◽  
Perovskite Solar Cells ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Metal Doping ◽  
The Stability

Phase composition of modern microcrystalline modifiers containing silicon, alkaline earth and rare earth metals

2020 ◽  
pp. 25-34
Author(s):  
V. P. Ermakova ◽  
◽  
S. Yu. Melchakov ◽  
V. G. Smirnova ◽  
L. A. Ovchinnikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Phase Composition ◽  
Alkaline Earth ◽  
Rare Earth Metals
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