Mercury complexes nitrogen ligands

The coordination of catenated nitrogen ligands to transition metals also dates back to the early work of Griess 89, 90), which included references to copper and silver derivatives of 1,3-diphenyltriazene. Around the turn of the century Meldola and Streatfeild 146-148), Meunier 150-152), Niemen-towski and Roszkowski 159), Cuisa and Pestalozza 55,56), and others reported extensively on triazene complexes of copper, silver, and mercury, and in the late 1930s and early 1940s Dwyer and colleagues 69-74) extended this work to include derivatives of nickel and palladium. However, most work on the coordination chemistry of triazenes and other catenated... 

Mercury(I) forms few complexes, one example is the linear [H2O-Hg Hg- H20] found in the mercury(I) nitrate dihydrate (above, p. 437), In contrast, mercury(II) forms a wide variety of complexes, with some peculiarities (a) octahedral complexes are rare, (b) complexes with nitrogen as the donor atom are common, (c) complexes are more readily formed with iodine than with other halogen ligands. 

S.2.4.2.3. Complexes of Mercury(l) with Nitrogen-Donor Ligands. 

Polyaza-, polythia-ligands. Recognition of transition metal ions. Replacing the oxygen sites with nitrogen or sulphur yields macrocycles and cryptands that show marked preference for transition metal ions and may also allow highly selective complexation of toxic heavy metals such as cadmium, lead and mercury [2.41-2.44, A.14]. 

Phosphorus magnetic shielding tensors, general phosphido ligands in transition metal complexes, 1, 472 Phosphorus(III) mercury compounds, preparation, 2, 425-426 Phosphorus—metal complexes, characteristics, 2, 34 Phosphorus—nitrogen-containing rings, chromium carbonyl link, 5, 225... 

Tetrahedral and octahedral complexes of zinc, cadmium, and mercury with a wide variety of nitrogen and oxygen donor ligands have been reported. Metal complexes... 

The structure of the first complex consists of [Hg2(C5H4NCl)2]2 + cations. The mercury is co-ordinated by the basic nitrogen of the pyridine to give effectively digonal co-ordination (Hg—Hg = 2.49 A L HgHgN = 167°). Derivations from linearity and deviations of the ligands from planarity are attributed to repulsion between the chloro-substituents on neighbouring cations.178... 

Mercury is the only group 12 member to have a substantial chemistry in the -1-1 oxidation state, in which Hg2 +, the most common of all metal polycations, is formed. This ion was the first one known to exhibit metal-metal bonding. Its chloride salt is the material present in the standard calomel reference electrode. In addition to halides and oxy salts, nitrogen and oxygen-donor ligand complexes of mercury(I) are known, but far fewer than of mercury(II). 

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