Calciums organo

E. Wang, L. Ma, L. Zhu and C.M. Stivanello, Calcium optical sensors based on lipophilic dichlorofluorescein anionic dye and calcium organo-phosphate ionophore or neutral carriers, Anal. Lett., 30(1) (1997) 33-44. 

Calcium Organo-calcium Calcium oxalate, weddellite type ... 

There has been a revival of interest in recent years in antimony mercaptides as alternatives to the organo-tin stabilisers. This stems from the low level of toxicity and the strong synergism with calcium stearate. However, compared to the... 

R. D. Rieke, T.-C. Wu, and L. 1. Rieke 147 HIGHLY REACTIVE CALCIUM FOR THE PREPARATION OF ORGANO-CALCIUM REAGENTS PREPARATION OF 1-ADAMANTYL CALCIUM HALIDES AND THEIR ADDITION TO KETONES 1 -(1 -ADAMANTYLJCYCLOHEXANOL... 

While organo-silane treatments are extensively used in both thermoset and elastomer applications, their use in thermoplastics has so far been somewhat restricted. This is because they do not react with the surface of calcium carbonate, one of the principal fillers used in this type of polymer and because of the lack of a suitable reactive functionality for most of the thermoplastic polymers. Today they are principally used in conjunction with glass fibres, calcined clays, aluminium and magnesium hydroxides, micas and wollastonite. The main thermo-... 

Calcium fluoride calcined with potassium fluoride affords benzyl fluoride (4) in 81% yield from benzyl bromide (3) on refluxing in acetonitrile.2,3 This reagent has been sucessfully used in the preparation of various other organo-fluorine compounds. 

Approximate contents of 14 minor and trace elements in oils produced from three coals by the catalytic hydrogenation process of Gulf Research and Development Co. were determined by emission spectroscopy. The results were compared with corresponding data for the original coals and the solid residues from the process. The contents of ash, sulfur, vanadium, lead, and copper are near or below the limits specified for an oil to be fired directly in a gas turbine while sodium and probably calcium are too high. Titanium appears to be somewhat enriched in the oils analyzed relative to other elements, suggesting its presence in organo-metallic complexes. 

Suess, E. Interaction of organic compounds with calcium carbonate. II. Organo-carbonate association in recent sediments. Geochim. Cosmochim. Acta 37, 2435—2447 (1973). 

Of the organometallic compounds of Group II elements, undoubtedly the chemistry of the magnesium compounds is best known. By contrast, the remaining elements in this group have received less attention and it is only recently that more information on organo derivatives of beryllium and, to lesser extent, of calcium, strontium, and barium has become available. Therefore, most of the observations regarding redistribution equilibria have been of more or less qualitative nature. 

NMR can provide detail regarding the types of NOM structures that are preferentially sorbed to mineral surfaces in soils and sediments. Simpson et al. (2006b) used H liquid-state and HR-MAS NMR methods to study the sorption of model compound mixtures to calcium-saturated montmorillonite. The model compound mixture included one representative compound from each of the following structural classes sugars, lignin, peptides, and long-chain aliphatics. After sorption, the supernatant was analyzed by liquid-state NMR and the organo-mineral complex... 

Calcium, Sr, and Ba metals are also activated in thf and other ethers or toluene when saturated with NH3. Syntheses of organo compounds, alkoxides, amides, etc., can be achieved readily from the metals by reaction with compounds having acidic H-atoms.12... 

Schematic experimental procedure is shown in Figure 1. All the chemicals used were of analytical grade, and ion-exchanged distilled water was used for aU the procedure. Amberhte IRC-76 (Organo K.K.) was used for cation exchange reactions. Its cation exchange capacity for 1 dm of wet resin is 200 g of CaCOs. The resin was treated in the diluted HCl solution to displace Na by H , and then treated in saturated CaCOs solution to displace H+ by Ca . After washing with the distilled water, 1 cm of wet Ca +-resin was dispersed in the 300 cm of the distilled water. Pure CO2 gas was introduced into the resin-dispersed solution at the constant flow rate (10 cm min i). Time variation of the pH value and Cs concentration of the resin-dispersed solution was analyzed by using pH / ion meter (Horiba K.K. model F-23 with pH and calcium ion electrodes).

The mineral elements can be held in the coal substance as organo-metallic salts, and also as a result of molecular adsorption and co-valent bonding. The mineral species dissolved in coal pore water, chiefly chlorides can also be considered as part of the inherent matter. The lignites and sub-bituminous coals can have a high fraction of the mineral elements, chiefly sodium, calcium and also aluminium and iron chemically combined in the fuel substance (9,10). The chemical reactivity and porosity of the fuel matrix decrease with the increase of coal age from lignite to bituminous rank. The loss of carboxyl, hydroxyl and quinone bonding sites in the fuel matrix results in a low "chemical" mineral matter content of bituminous coals. 

The sulphide, carbonate, chloride and organo-metal species dissociate and oxidize in the flame. The oxides may remain as discrete particles, chiefly iron oxide (magnetite), can dissolve in the glassy phase of silicates, and a fraction of calcium and sodium oxides are sulphated ( 5). Thus the initial deposit material will contain some calcium, sodium and potassium sulphate. The latter originates from the release of potassium in the flame heated aluminosilicate particles ( ). ... 

Calcium Soaps, and Organo Compounds in Poly(vinyl chloride) Stabilization... 

Very little is yet known about the physical properties of organo-calcium, -strontium, or -barium compounds. The preparation and properties of organic derivatives of the Second Group have been reviewed by Baluyeva and Ioffe89 and by Ioffe and Nesmeyanov.90... 

Another process likely to occur is calcite precipitation, when pH and calcium concentration are both high. The NOM then adsorbs on the calcite surface. Suess (1973a, 1973b) measured the selective adsorption of organics onto calcite and mentioned the possibility of h] drated organo-calcium complexes on calcite surfaces. He described the thick layer of organics on the calcite surface as nitrogen-rich, possibly protein-like substances. 

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