POSSIBLE CALORIMETRIC METHOD FOR MEASUREMENT OF THE LIGAND FIELD SPLITTING ENERGIES FOR THE HEXAAQUO CATIONS OF SOME TRANSITION ELEMENTS

1965 ◽  
Vol 43 (8) ◽  
pp. 2148-2156 ◽  
Author(s):  
J. W. S. Jamieson ◽  
G. R. Brown ◽  
D. W. Gruener ◽  
R. V. Peiluck ◽  
R. A. LaMontagne
Keyword(s):  
Divalent Cations ◽  
High Energy ◽  
Ligand Field ◽  
Transition Elements ◽  
Theoretical Justification ◽  
Field Splitting ◽  
Iron Cobalt ◽  
Heats Of Solution ◽  
Vacuum Dehydration ◽  
Cobalt And Nickel

High energy modifications of the lower hydrates of the divalent sulfates of manganese, iron, cobalt, and nickel have been prepared by vacuum dehydration. The heats of solution of these materials have been measured and compared with the heats of solution of the normal crystalline lower hydrates. The maximum heats of transition appear to be proportional to the ligand field splitting energies for the corresponding hexaaquo divalent cations, although theoretical justification for this correlation is not yet obvious.

HIGH ENERGY MODIFICATIONS OF THE HYDRATES OF ZINC SULFATE

1965 ◽  
Vol 43 (12) ◽  
pp. 3129-3132 ◽  
Author(s):  
J. W. S. Jamieson ◽  
R. A. Lamontagne ◽  
Barbara A. Pattern ◽  
G. R. Brown
Keyword(s):  
Zinc Sulfate ◽  
High Energy ◽  
Crystalline Form ◽  
Ligand Field ◽  
Field Splitting ◽  
Maximum Heat ◽  
Heats Of Solution ◽  
Splitting Energy ◽  
Heat Of Transition ◽  
Vacuum Dehydration

Much higher heats of solution than have previously been observed for hydrates of zinc sulfate have been measured for various new vacuum dehydration products. It is suggested that the maximum heat of transition to normal crystalline form of 82.8 cal/g, 23.8 kcal per mole of heptahydrate, or 8.3 × 103 cm−1 is a satisfactory measure of the ligand field splitting energy for the hexaaquozinc(II) ion.

Ligand field splitting energies of the hexaamminecobalt(II) ion and the hexaamminenickel(II) ion measured by a calorimetric method

1970 ◽  
Vol 48 (14) ◽  
pp. 2177-2181 ◽  
Author(s):  
Badri Muhammad ◽  
J. W. S. Jamieson
Keyword(s):  
Close Agreement ◽  
High Energy ◽  
Calorimetric Method ◽  
Ligand Field ◽  
Maximum Difference ◽  
Kcal Mole ◽  
Heat Of Solution ◽  
Field Splitting ◽  
Heats Of Solution ◽  
Splitting Energy

Various normal lower ammines and high-energy modifications of the lower ammines of cobalt(II) sulfate and nickel(II) sulfate have been prepared and the heats of solution in dilute ammonia have been measured for both types. For each of these ammine systems the maximum difference in heat of solution, expressed as kcal/mole of each heptaammine, between the high-energy and the normal salts has been found to be in close agreement with the ligand field splitting energy of the hexaamminemetal(II) ion.

scholarly journals Thermochemical measurement of the ligand field splitting energies for hexaaquocopper(II) and hexaamminecopper(II)ions

1979 ◽  
Vol 57 (15) ◽  
pp. 1926-1931 ◽  
Author(s):  
Muhammad Badri ◽  
James W. S. Jamieson
Keyword(s):  
Spectroscopic Method ◽  
Energy Difference ◽  
High Energy ◽  
Maximum Energy ◽  
Ligand Field ◽  
Heat Of Solution ◽  
Ammine Complexes ◽  
Field Splitting ◽  
Order Of Magnitude ◽  
The Right

The vacuum dehydration of copper(II) sulphate pentahydrate has been shown to pass through the transitory trihydrate state before proceeding to the monohydrate composition. Based on this, the heat of solution data for the high-energy modification hydrates have been reinterpreted and the low-energy crystalline hydrates of various compositions have been prepared and their heats of solution measured. From the heat of solution data the maximum energy difference expressed in kcal/mol heptahydrate appears to be of the right order of magnitude to be regarded as the ligand field splitting energy for the hexaaquocopper(II) ion. Similar measurement for the ammine complexes of copper(II) sulphate has also been done and the maximum energy difference was found to agree well with the value of LFSE obtained by spectroscopic method.

Thermochemical measurement of the ligand field splitting energies for hexaammine complexes of Mn(II), Fe(II), and Zn(II)

1977 ◽  
Vol 55 (20) ◽  
pp. 3530-3535
Author(s):  
M. Badri ◽  
J. W. S. Jamieson
Keyword(s):  
Metal Ion ◽  
High Energy ◽  
Ligand Field ◽  
Maximum Difference ◽  
Heat Of Solution ◽  
Field Splitting ◽  
Order Of Magnitude ◽  
Splitting Energy ◽  
The Right ◽  
Right Order

Various lower ammines and high-energy modifications of lower ammines of the sulphates of Mn(II), Fe(II), and Zn(II) have been prepared and their heats of solution have been measured. For each of these ammine systems, the maximum difference in heat of solution, expressed in kcal/mol of heptaammine, has been found to be of the right order of magnitude to be regarded as the ligand field splitting energy for the hexaammine complex of the metal ion.

Progress in preparation and characterization of silylene iron, cobalt and nickel complexes

2021 ◽  
Author(s):  
Wenjing Yang ◽  
Yanhong Dong ◽  
Hongjian Sun ◽  
Xiaoyan Li
Keyword(s):  
Nickel Complexes ◽  
Electron Cloud ◽  
Synthesis And Characterization ◽  
Iron Cobalt ◽  
Cloud Density ◽  
Cobalt And Nickel

The synthesis and characterization of Fe, Co and Ni complexes supported by silylene ligands in recent ten years are summarized. Due to the decrease of electron cloud density on Si...

scholarly journals New insights on Br speciation in volcanic glasses and structural controls on halogen degassing

2020 ◽  
Vol 105 (6) ◽  
pp. 795-802 ◽  
Author(s):  
Marion Louvel ◽  
Anita Cadoux ◽  
Richard A. Brooker ◽  
Olivier Proux ◽  
Jean-Louis Hazemann
Keyword(s):  
Atmospheric Chemistry ◽  
Divalent Cations ◽  
Stratospheric Ozone ◽  
High Energy ◽  
Aluminosilicate Glass ◽  
High Energy Resolution ◽  
Magma Chambers ◽  
Structural Controls ◽  
Volcanic Glasses ◽  
Melt Composition

Abstract The volcanic degassing of halogens, and especially of the heavier Br and I, received increased attention over the last 20 years due to their significant effect on atmospheric chemistry, notably the depletion of stratospheric ozone. While the effect of melt composition on halogen diffusion, solubility, or fluid-melt partitioning in crustal magma chambers has been thoroughly studied, structural controls on halogen incorporation in silicate melts remain poorly known, with only few studies available in simplified borosilicate or haplogranite compositions. Here, we demonstrate that high-energy resolution fluorescence detection X-ray absorption spectroscopy (HERFD-XAS) with a crystal analyzer spectrometer (CAS) is well-suited for the study of Br speciation in natural volcanic glasses which can contain lower Br concentrations than their laboratory analogs. Especially, HERFD-XAS results in sharper and better-resolved XANES and EXAFS features than previously reported and enables detection limits for EXAFS analysis down to 100 ppm when previous studies required Br concentrations above the 1000 ppm level. XANES and EXAFS analyses suggest important structural differences between synthetic haplogranitic glass, where Br is surrounded by Na and next-nearest oxygen neighbors, and natural volcanic glasses of basaltic to rhyodacitic compositions, where Br is incorporated in at least three distinct sites, surrounded by Na, K, or Ca. Similar environments, involving both alkali and alkaline earth metals have already been reported for Cl in Ca-bearing aluminosilicate glass and our study thus underlines that the association of Br with divalent cations (Ca2+) has been underestimated in the past due to the use of simplified laboratory analogs. Overall, similarities in Cl and Br structural environments over a large array of compositions (46–67 wt% SiO2) suggest that melt composition alone may not have a significant effect on halogen degassing and further support the coupled degassing of Cl and Br in volcanic systems.

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