Tris complex with water

Nickel(0) complexes with water-soluble phosphines have attracted interest in the context of homogeneous catalysis. A comprehensive study of the coordination chemistry of tris(sodium-m-sulfonatophenyl)phosphine (1039) has appeared.2504 The complexes [Ni(CO)2(1039)2] 6HzO have been made by reaction of (1039) with Ni(CO)4 under phase-transfer conditions, and the homo-leptic [Ni(1039)3]-9H2O has been made from Ni° precursors and (1039) under phase-transfer conditions, or from NiCl2, (1039), and BH4 in water. A related complex [Ni(CO)2(1040)2] with the bidentate ligand (1040) has also been studied.2505... 

Lanthanide(III) ions form three distinct types of complexes with 1,3-diketones (p-diketones) (a) tris complexes with a metal-to-ligand ratio of 1 3, (b) Lewis-base adducts of tris complexes, and (c) tetrakis complexes with a metal-to-ligand ratio of 1 4 (Binnemans, 2005a). It is very difficult to obtain pure monomeric tris complexes, because the coordination number of the lanthanide ion in this type of compounds is six and this is too low for saturation of the first coordination sphere of a trivalent lanthanide ion (except for tris complexes of very bulky 1,3-diketones). Therefore, most of the tris complexes form either dimeric (or even oligomeric or polymeric) complexes, or they form hydrates. The water molecules act as Lewis bases and by addition of... 

Reaction of the cyclopentadienyl rhodium and iridium tris(acetone) complexes with indole leads to the species 118 (M = Rh, Ir) [77JCS(D)1654 79JCS(D)1531]. None of these compounds deprotonates easily in acetone, but the iridium complex loses a proton in reaction with bases (Na2C03 in water, r-BuOK in acetone) to form the ri -indolyl complex 119. This reaction is easily reversed in the presence of small amounts of trifluoroacetic acid. 

The value of the tris(pyrazolyl)hydroborato complexes [TpRR ]ZnOH is that they are rare examples of monomeric four-coordinate zinc complexes with a terminal hydroxide funtionality. Indeed, [TpBut]ZnOH is the first structurally characterized monomeric terminal hydroxide complex of zinc (149). As such, the monomeric zinc hydroxide complexes [TpRR ]ZnOH may be expected to play valuable roles as both structural and functional models for the active site of carbonic anhydrase. Although a limitation of the [TpRR ]ZnOH system resides with their poor solubility in water, studies on these complexes in organic solvents... 

Tri-tert-butoxidesilanethiolate forms complexes with both Co11 and Co111. Reaction of the thiol with a Co11 ammine in water yields a dimer which undergoes oxidation in an ammonia-saturated atmosphere to form octahedral [Co(SSi(0-t-Bu)3)2(NH3)4]+, the first silanethiolate characterized structurally.1044... 

Tris(2-aminoethyl)amine (tren) and hexamethyl tren form pentacoordinate complexes with a bound water. The enthalpies of ionization have been determined.242 These results dispute the data from the systems that led to the view that solvent structure mediates the pAia of zinc bound water in zinc hydrolytic enzymes. The effect was shown to be entirely enthalpic. 

Ellis, J.W., Harrison, K.N., Hoye, P.A.T., Orpen, A.G., Pringle, P.G., and Smith, M.B., Water-soluble tris(hydroxymethyl)phosphine complexes with nickel, palladium, and platinum. Crystal structure of Pd P(CH2OH)3 4].cntdot.CH3, Inorg. Chem., 31, 3026, 1992. 

Early determinations of iron and hemoglobin in blood were described by Herrmann et al53) and Bohmer et al 54). Zettner and co-workers ss) determinent serum iron by extracting the bathophenanthroline complex into MIBK. The serum could be diluted with water and aspirated only if the iron level was above 2 ppm. Rodgerson and Heifer S6) tried aspirating undiluted serum but obtained irreproduc-... 

The first non-heteroatom-substituted carbene complex was prepared by Schrock in 1974 [392] (Figure 3.4). Treatment of tris(neopentyl)tantalum dichloride with neopentyllithium led to the formation of neopentane and (2,2-dimethyl-1-propylidene)tris(neopentyl)tantalum. This carbene complex reacts violently with water or oxygen, but can be sublimed (80 °C) and stored indefinitely at room temperature under argon. 

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