Coordination compounds monodentate

Coordination compounds containing bidentate ligands are often thermally more stable than those comprised of related monodentate ligands, e.g. ethylenediamine (en) complexes dissociate at a higher temperature than those of ammonia or pyridine. Compounds containing a ring structure, such as coordinated salicylaldehyde (sal) and acetyl-acetonate (acac), are particularly stable, and may often be sublimed... 

NMR measurements also provide information on the coordination of the ligands in the uranyl polymers. Solid-state I c-NMR confirms the coordination modes of the carboxylate ligands to the uranyl ion that is, both monodentate and bidentate carboxylate coordination modes are evident. The uranyl dicarboxyl ate polymers which possess two moles of coordinated DMSO exhibit two carbon-13 carbonyl resonances, one at about 175 ppm downfield from tetramethylsilane (TMS) and one at about 185 ppm. The polymers which possess only one mole of coordinated DMSO exhibit only the carbonyl peak near 185 ppm. Based on other known coordination compounds, the 175 ppm peak can be assigned to monodentate carboxylate and the 185 ppm peak to bidentate carboxylate. Thus, 7-coordination predominates in the polymers with either one or two moles of solvent coordinated to the uranyl ion, which is consistent with the infrared results reported elsewhere (5). 

Hitoshi dedicated his life to Science and to the organization of Science. As a scientist, I remember the studies by X-ray of the coordination compounds in solution of metal ions with monodentate ligands which constituted milestones in the field. Eventually, he started simulating through informatic tools the interaction of solvents and ligands with metal ions. 

Names for Mononuclear Coordination Compounds with Monodentate Ligands... 

A slightly different situation is observed in coordination compounds formed by hydrazides of carbonic acids [112]. In this case, together with complexes 419 and 420 which are closely related to 417 and 418, the structure 421 is formed, which for the examined compounds has been found to behave as a monodentate N-donor ligand [112] ... 

Figure 13 Schematic representation of coordination compounds with rigid monodentate ligands bearing hydrogen bonding groups (e.g. substituted pyridines). Arrangements VII-XVI are representative of 4-pyridine ligands and arrangements XVII-XXI of 3-pyridine ligands.

Fe2(CO)9, and Fe3(CO)12, respectively. Similar disproportionations occurred with Ni(CO)4 and Co2(CO)8 which gave anionic species such as [Ni2(CO)6]2, [Ni3(CO)8]2, [Co(CO)4] , etc., upon treatment with ammonia or other amines. In contrast to the carbonyls of iron, nickel and cobalt, those of chromium, molybdenum and tungsten reacted with pyridine and 1,2-ethylenediamine to afford substitution products of the general composition M(CO)6 (py) (n = 1, 2, and 3) and M(CO)4(en) with the metal remaining in the oxidation state zero [25], Mainly as the result of this work, Hieber became convinced that the metal carbonyls should be regarded as true coordination compounds, and the coordinated CO should not be considered a radical but a monodentate ligand like NH3, pyridine, etc. He held this view despite the criticism by several of his contemporaries [3, 19] and was very pleased to see that in most textbooks published after 1940 this view had been accepted. 

Many of these can only act as monodentate or bridging ligands (91)-(95), (98), (99) in the bridging mode, M- M interactions can be mediated by the bridge. Such interactions are measured by magnetic coupling or electron transfer see Electron Transfer in Coordination Compounds), and the... 

Reactivity studies of jj -acyl complexes are limited. Compounds (115) react with CO to afford octahedral cis.trans- ) -acyl complexes (121), probably via prior conversion to a coordinatively unsaturated monodentate (see Monodentate Ligand) acyl (equation 27). The cis,trans-( 2 ) then isomer-izes to trans,trans-( l ). Phenylacetylene reacts with (115 R = R = Et) to give a mixture of acyl-alkyne coupling products,that is (122). Reaction with the R = i-Pr compound proceeds in a different way, by equilibration to the -alkyl, followed by aUcyl-alkyne coupling, and finally CO insertion to give rf--diCy complex (123). ... 

Eanthanide triflates reacts with PhsPO in ethanol forming [En(OTf)2(Ph3PO)4] OTf (Ln = La, Nd, Er, Lu). The erbium and lutetium compounds have octahedral coordination, with monodentate triflates, but the complexes of the larger La and Nd have seven-coordination with one triflate being bidentate. 

The azide group can function as a monodentate ligand in coordination compounds such as [Co(N3)2en2]N03 and [Co(N3)(NH3)s](N3)2, - and here again the differences between N-N bond lengths are not too certain. In these complexes the angle between Co—N and the linear N3 group is around 125°. The... 

MONONUCLEAR COORDINATION COMPOUNDS WITH MONODENTATE LIGANDS... 

Mononuclear coordination compounds with monodentate ligands 495... 

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