Tropolone complexes

A variety of derivatives of bis-[Bi(tr)2X, X = Cl or N03], tris-(Bitr3), and tetra-([Bi(tr)4X][Na]) tropolonate complexes of bismuth (178, 179) have been prepared and spectroscopically characterized (176, 177, 180). Solid-state structures for examples of bis-(tropolonate) derivatives confirm the chelate interaction (171) and in the case of the nitrate derivative, reveal intermolecular alkoxide-bismuth [Bi-0 2.688 and 2.666 A] dimer contacts 52, which are slightly longer than the chelate bonds [Bi-0 2.130-2.323 A],... 

Long intermolecular contacts have been observed (44) for Sc ax ac)3. The shortest H—H and C—H contacts are 2.49 and 2.95 A respectively. All O—H s are about 3 A except for one contact of 2.56 A. The average intrachelate oxygen-oxygen separation ( bite ) is about 2.715 A while the interchelate separations have two average values 2.956 A for the oxygens in plane and related by the Cs axis whereas the value for those between these planes is 3.095 A (cf. see tropolonate complex). 

Fig. 5. (a) The structure of Sc(III)-tris-tropolonate complex with bond distances and angles (b) the coordination polyhedron around hexacoordinated Sc(III)... 

An isolated study of the tris tropolonate complex (179) of chromium(III) has appeared 787 mass spectra were recorded and fragmentation patterns discussed. 

Tropolone complexes (20) also undergo electrophilic substitution, but the numerous positions for reaction give rise to mixtures of products. The p-keto imine complexes (21) and (22)32 have been brominated successfully using )V-bromosuccinimide. 

A differential pulse CSV method for the determination of traces of butyltin species in water was compared with two other voltammetric methods, namely differential pulse polarography and ASV (Schwartz et at., 1995). The butyltin species were accumulated on the mercury drop electrode as their tropolone complexes. Detection limits were 5 mg 1 1 for tributyltin (TBT), 0.5 mgl-1 for dibutyltin (DBT) and 0.5 mgl-1 for monobutyltin (MBT). These detection limits were better than the corresponding values obtained in the other analytical methods. 

For the cationic pentacoordinate tropolonates there appears to be an effect of the nature of the non-chelating group R on chemical shift. Those tropolone complexes in which the silicon atom is bonded to an sp hybridized carbon in R ([47] and [48]) exhibit a chemical shift of — 141 ppm compared with hexacoordinate T3Si (<3 = — 139 ppm). 

Because palladium complexes are reactive in various solvents (Scheme 15.1), we present the following tropolonate complexes as a case study. The interpretation of NMR spectra, which typically contain multiple features, can be exhausting to clarify quantitatively, and the application of X-ray crystallography can thus partially circumvent this problem. 

Coordination number 10 has been demonstrated in [La(EDTA) (H20)4] and presumably occurs in various complexes of Th and U, such as the tropolone complexes [M(02C7H5)5]". A bicapped square antiprismatic arrangement has been found in K4Th(02CC02)4 4H20.17... 

Kudo et al. studied the sum peak intensity ratios of In-labeled samples involving bovine serum albumin, human platelet (%Us, indium chloride, and indium tropolone complex. From the measured value of the sum peak intensity ratio, the PAC parameter Gj was calculated using Eq. (20). The results are shown in Fig. 23. Both the ratios for 171 keV Y and 24S keV y give straight lines when they are plotted against Gj for various samples. It is interesting to note that the different specimens of human fdatelet cells (b), (b), and (b)" show different G2. This may be due to the difference in environments of In which reflect the difference of material components in the cells of individuals. 

I245 for sampte b, b, b" (human plat cells), c (saline solution of InCl,), aiul d ( "In-tropolone complex)... 

Physical properties of mesogens with bidentate sulfur ligands Benzoato complexes Tropolone complexes... 

Penta(tropolonato)-protactinium and -uranium have been prepared using tropolone and the metal pentaethoxide in benzene. Uranium pentachloride reacts with an excess of tropolone in non-aqueous solvents to give chlorotetra(tropolonato)uranium. Enthalpies of formation of tri(tropolonato)- and tri(4-methyltropolonato)-aluminium (ill) have been determined at 298.15 K by solution calorimetry. The gas phase enthalpies of formation have been calculated and from these the A1—O bond energies derived. The crystal and molecular structure of a tetranuclear cobalt(ii)-tropolonate complex, [Co4(C7H502)s(H20)2] has been reported. Spectroscopic data (i.r., n.m.r.) of a mercury (ii) tropolonate indicates that it has an unsymmetrical structure with two approximately linear short Hg—O bonds and two longer ones. ... 

DyrasenSSi. reports the extraction of a uranium (Vl)-beta-lsopropyl tropolone complex with ohloroform and hexone. 

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