A unique heterobimetallic benzyl calciate—an organometallic mixed-metal species involving a heavy alkaline-earth metal

2008 ◽  
pp. 1692 ◽  
Author(s):  
Marites A. Guino-o ◽  
Charles F. Campana ◽  
Karin Ruhlandt-Senge
Keyword(s):  
Alkaline Earth ◽  
Earth Metal ◽  
Metal Species ◽  
Alkaline Earth Metal ◽  
Mixed Metal

scholarly journals Theoretical study on the binding selectivity of 18-membered azacrown ethers with alkaline earth metal species

2018 ◽  
Vol 1 (1) ◽  
pp. 17
Author(s):  
Saprini Hamdiani ◽  
Lalu Rudyat Telly Savalas ◽  
Agus Abhi Purwoko ◽  
Saprizal Hadisaputra
Keyword(s):  
Density Functional ◽  
Alkaline Earth ◽  
Theoretical Study ◽  
Earth Metal ◽  
Metal Species ◽  
Stable Complex ◽  
Alkaline Earth Metal ◽  
Interaction Energies ◽  
Binding Selectivity ◽  
Azacrown Ethers

The binding selectivity of 18-membered azacrown ethers (monoaza- N1, diaza- N2, triaza- N3, tetraaza- N4, pentaaza- N5, and hexaaza-18-crown-6 N6) with Ca2+, Sr2+, Ba2+ have been studied by density functional theory (DFT) calculations. The complex binding selectivity was analyzed in term of interaction energies, thermodynamic properties, second order interaction energies, and charge transfer effects. The geometrical study shows that Ca2+ and azacrown complexes acquire envelope like structure, leading to shorter bond lengths. As a result, these complex systems have the highest interaction energies. Theoretical study also showed that N6 complex with alkaline earth metal ion were shown to be more stable complex than those ligand with lower nitrogen number. The interaction energy order is N0 < N1 < N2 < N3 < N4 < N5 < N6. This trend shows that the presence of more nitrogen on the crown ether cavity increases the interaction energies by approx. 7.3 % in going from N0 to N6. It is clearly showed that the contribution of the number of nitrogen play a dominant role in the binding selectivity of these systems.  

scholarly journals Integrated Leaching and Thermochemical Technologies for Producing High-Value Products from Rice Husk: Leaching of Rice Husk with the Aqueous Phases of Bioliquids

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6033
Author(s):  
Wenran Gao ◽  
Hui Li ◽  
Karnowo ◽  
Bing Song ◽  
Shu Zhang
Keyword(s):  
Rice Husk ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Chemical Compounds ◽  
Carbon Chain ◽  
Hydrothermal Liquefaction ◽  
Metal Species ◽  
Alkaline Earth Metal ◽  
Bio Oil ◽  
Thermal Stability Of

It remains challenging to develop a techno-economically feasible method to remove alkali and alkaline earth metal species (AAEMs) from rice husk (RH), which is a widely available bioresource across the world. In this study, the AAEMs leaching effect of aqueous phases of both bio-crude prepared by hydrothermal liquefaction (AP-HT) and bio-oil prepared by pyrolysis (AP-Pyro) of RH were systematically investigated. The results indicated that although the acidity of AP-HT and AP-Pyro are much lower than that of HCl, they performed a comparable removal efficiency on AAEMs (Na: 56.2%, K: 96.7%, Mg: 91.0%, Ca: 46.1% for AP-HT, while Na: 58.9%, K: 96.9%, Mg: 94.0%, Ca: 86.3% for AP-Pyro) with HCl. The presence of phenolics in bio-oil could facilitate the penetration of water and organic acids into the inner area of RH cells, thus enhancing the AAEMs removal via chelate reactions. The thermal stability of leached RH during thermochemical conversions was studied via TG and Py-GC-MS. The results showed that the heat conduction efficiency in leached RH was enhanced with a high pyrolysis rate, resulting in a narrow carbon chain distribution (C5–C10) of derived chemical compounds.

scholarly journals Imidazol-2-ylidene-N′-phenylureate ligands in alkali and alkaline earth metal coordination spheres – heterocubane core to polymeric structural motif formation

2015 ◽  
Vol 44 (16) ◽  
pp. 7458-7469 ◽  
Author(s):  
Kishor Naktode ◽  
Jayeeta Bhattacharjee ◽  
Hari Pada Nayek ◽  
Tarun K. Panda
Keyword(s):  
Alkaline Earth ◽  
Earth Metal ◽  
Structural Motif ◽  
Metal Coordination ◽  
Alkaline Earth Metal ◽  
Polymeric Structure ◽  
Mixed Metal ◽  
Structural Details ◽  
Coordination Spheres

Synthetic and structural details of imidazol-2-ylidene-N′-phenylureate ligand supported two potassium complexes with a hetero-cubane K4O4 core and a polymeric structure, along with a mixed metal Ca–K complex are presented.

scholarly journals Effect of alkali and alkaline earth metal species on the combustion characteristics of cattle manures

RSC Advances ◽  
2018 ◽  
Vol 8 (21) ◽  
pp. 11705-11713 ◽  
Author(s):  
Baojun Yi ◽  
Qiaoxia Yuan ◽  
Hongliang Cao ◽  
Wenjuan Niu ◽  
Ming Wang ◽  
...  
Keyword(s):  
Alkaline Earth ◽  
Earth Metal ◽  
Combustion Characteristics ◽  
Metal Species ◽  
Alkaline Earth Metal

This study investigates the effects of alkali and alkaline earth metal (AAEM) species on the combustion characteristics of cattle manures (CM). Different AAEM species (K, Na, Ca, and Mg) were mixed with CM and deashing CM (D-CM) samples.

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