Tetraammines

The properties of copper(Il) are quite different. Ligands that form strong coordinate bonds bind copper(Il) readily to form complexes in which the copper has coordination numbers of 4 or 6, such as tetraammine copper(Tl) [16828-95-8] [Cu(NH3)4], and hexaaquacopper(Il) [14946-74-8] [Cu(H,0),p+ ( see Coordination compounds). Formation of copper(Il) complexes in aqueous solution depends on the abiUty of the ligands to compete with water for coordination sites. Most copper(Il) complexes are colored and paramagnetic as a result of the unpaired electron in the 2d orbital (see Copper... 

On boiling the Magnus salt with ammonia solution, it is converted into the tetraammine... 

Cobalt, p-pe roxobis(pentaammine)-cyclic voltammetry, 1, 482 Cobalt, tetraammine-structure, 1, 8... 

Cobalt, tetraamminepyrophosphato-structures, 1, 202, 203 Cobalt, tetraammine(sarcosine)-chirality, 1,198 Cobalt, triammine-structure, 1, 8—10 Cobalt, tricarbonato-reactions, 1,22 Cobalt, tricarbonylnitroso-exchange reactions, 1, 290 Cobalt, trichloro-equilibrium constant, 1, 517 Cobalt, trichlorobis(triethylphosphine)-structure, 1, 45... 

Copper, hexakis(pyridine 1-oxide)-diperchlorate structure, 1, 53 Copper, hexakis(2-pyridone)-diperchlorate structure, 1,53 Copper, tetraammine-history, 1, 2... 

Palladium, polymethylenebis(diphenylphosphine)-bis(thiocyanato)-linkage isomers, 1, 185 Palladium, tetraammine-tetrachloropalladate history, 1, 2 Palladium, tetrachloro-crystal structure, 1, 16 Palladium, tris(dinitrogen)-synthesis, 1,28 Palladium complexes a,(5-dione dioximates electrical properties, 6, 143 acetylacetone hydrolysis, 2,379 alkylperoxo... 

Platinum, hexachloro-ammonium salt structure, 1,16 Platinum, tetraammine-amminctrichloroplatinate polymerization isomerism, 1,187 dichloride structure, l, 16... 

For example, Pt/Si02 catalysts are conveniently made by impregnating a silica support vith a basic solution (pH 8-9) of platinum tetraammine ions, Pt(NH3)4 (dissolved as chloride). As the silica surface is negatively charged, the Pt-containing ions attach to the SiO entities and disperse over the surface. The pH should be kept belo v 9 because other vise the silica surface starts to dissolve. 

There is tentative evidence for the lower reactivity of the hexaammine species in high ammonia concentration. The tetraammine (diaquated) and lower ammine Co(II) species do not pick up O2 over relatively long periods (75). 

Iversen, B.B., Larsen, F.K., Figgis, B.N. and Reynolds, P.A. (1997) X-N study ofthe electron density distribution in tra s-tetraammine-dinitronickel(II) at 9K transition metal bonding and topological analysis, J. Chem. Soc., Dalton Trans. 2227-2240. 

Figgis, B.N., Reynolds, P.A. and Mason, R.J. (1983) Covalent bonding in trans-tetraammine-dinitronickel(II) studied by polarised neutron diffraction, J. Am. Chem. Soc., 105, 440 143. 

Case Study Pt Tetraammine Adsorption over Silica. 177... 

CASE STUDY Pt TETRAAMMINE ADSORPTION OVER SILICA... 

Tetraacrylonitrilecopper(I) perchlorate, 3510 Tetra(3-aminopropanethiolato)trimercury perchlorate, 3582 Tetraamminebis(dinitrogen)osmium(II) perchlorate, 4071 Tetraammine-2,3-butanediimineruthenium(III) perchlorate, 1794 Tetraamminecadmium permanganate, 3956 Tetraamminecopper(II) bromate, 0264 Tetraamminecopper(II) nitrate, 4276 Tetraamminecopper(II) nitrite, 4275 Tetraamminecopper(II) sulfate, 4274 Tetraamminedithiocyanatocobalt(III) perchlorate, 0969... 

Of the two kinds of numerical prefix (see Table 4.2), the simple di-, tri-, tetra-, etc. are generally recommended. The prefixes bis-, tris-, tetrakis-, etc. are to be used only with more complex expressions and to avoid ambiguity. They normally require parentheses around the name they qualify. The nesting order of enclosing marks is as cited on p. 13. There is normally no elision in instances such as tetraammine and the two adjacent letters a are pronounced separately. 

When added to a dilute solution of caustic soda or caustic potash, it forms [Sb(OH)6] ion in the solution, from which the sodium or potassium salt, NaSb(OH)e or KSb(OH)6 crystaUizes out. It forms two adducts with ammonia, a red triammine, SbCls 3NHs, and a colorless tetraammine, SbCls 4NHs. SbCls dissociates on heating to trichloride and chlorine dissociation comenc-ing around 120°C and completing at 300°C. 

The green and violet tetraammines have the same chemical composition, that is, they are isomers and are the only two isomers with this composition. Werner realized that this was possible only if the six ligands were deployed about the cobalt(III) center in an octahedral arrangement (cf. octahedral coordination in solids, Sections 4.3 and 4.4) for example, a flat hexagonal complex Co(NH3)4Cl2+ would have three isomers, like ortho-, meta-, and para-disubstituted benzenes. Werner correctly identified the green compound as the trans isomer (chloro ligands on opposite sides of the octahedron) and the violet as cis (same side), as in Fig. 13.1. 

RuC12N2C12HiB, Ruthenium(II), bis-(acetonitrile)dichloro(T) l-l, 5-cyclooctadiene)-, 26 69 RuC12N2C22H22, Ruthenium(II), bis-(benzonitrile)dichloro(T)5-l, 5-cyclooctadiene)-, 26 70 RuC1iH12N4, Ruthenium(III), tetraammine-dichloro-... 

The tetraammines are the most stable species adducts having more than four NH3 present are stable only at low temperature. The table is compiled from data given in ref. 74.)... 

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