Cadmium thiolate

For even better volatility the fluorinated aryl substituent C6H2(CF3)3 has been employed, as in the cadmium thiolate [Cd S(C6H2(CF3)3) 2] which sublimes at 160 °C under vacuum. When used in deposition the hexagonal phase of CdS was predominant with growth temperatures in the range 425 175 °C, with no fluorine incorporation in the CdS films being observed.232... 

Cf produces two fission products that travel in opposite directions. If one projectile hits the sample, ions will be produced. These ions may then be focused and measured by TOF MS. The other projectile may be used to measure the start of the ionization process. This method has been used to study the ions produced from the ionization of metal complexes such as cadmium thiolates (33) and lanthanide phthalocyanine complexes (34). This method has also been used on metal oxides such as La203 to produce metal oxide cluster ions (35). 

Rauser, W.E., Hartmann, H.-J. Weser, U. (1983). Cadmium-thiolate protein from the grass Agrostis gigantea. FEBS Letters 164, 102-4. 

The above stereospecific tiirane polymerisations have generally been run in heterogeneous systems. Such conditions essentially make it impossible to determine the detailed structure of active species involved in these polymerisations. Thus, enantiosymmetric and enantioasymmetric polymerisations of propylene sulphide have also been studied in a homogeneous phase by using chiral cadmium thiolates of cysteine esters and chiral cadmium carboxylates of cysteine and methionine [157,160-164]. The most studied is living polymerisation using the cadmium derivative of the isopropyl ester of (.S)-cysteine [160] ... 

Figure 7 The (a) and a (b) cadmium-thiolate domain structures in mammalian metallothionein. Yellow spheres represent Cys-sulfurs and Green spheres represent Cd(ll) atoms. Based on models developed in our laboratory, for example, Ref. 41...

The cadmium thiolate complexes [Cd(Tm/ Tol)(SR)] (R = Bn, Ph, p-Tol, C6F5) were prepared by the reaction of [CdBr(Tm/ "To1)] with equimolar amounts of the corresponding thallium thiolates. [CdSPh(Tm/7"To1)] is a four-coordinate species exhibiting a distorted tetrahedral geometry in the solid state.53... 

Existing data on phytochelatins and related polypeptides show that they differ from MT not only in biosynthesis but also in structure. Whereas no 3D structure has yet been reported, electronic spectroscopy (c.d. and UV-Vis) and EXAFS data on Cd-7-EC peptides led to different proposals as to the nature of the cadmium binding in such peptides, polynuclear cadmium thiolate aggregates versus isolated Cd(SCys)4 units, respectively. However, contrary to the conclusion of the previous work, a recent X-ray absorption spectroscopy study on Cd-7-EC peptides and model systems provides evidence for the formation of a polynuclear cadmium cluster. " ... 

Gonzalez-Duarte. P. Clegg. W. Casals, I. Sola, J- Rius, J. Unprecedented poly crystal structure of a new cadmium thiolate containing an unusually highly charged... 

Tacticity (stereoregularity) % Coordination polymerization, cadmium thiolate catalyst Isotactic 90-100 meso dyads (6, 9-11)... 

Several reports related to CdS nanocrystals incorporated in PS matrix have been reported in the literature [200-202]. Zhao et al. described preparation of small nanoparticles of CdS by a hydrothermal procedure in an aqueous solution that yields transparent CdS/PS nanocomposite films [200]. CdS/PS nanocomposites were also prepared successfully using in-situ thermolysis synthesis of a cadmium thiolate precursor dispersed in the polymer [201, 202]. The preparation of CdS/PS via a thermolysis method has several interesting advantages with respect to the common methods of precipitation for example, the CdS precursor is easy to prepare and is stable under normal conditions. The thermal and structural properties of CdS/PS nanocomposites also were broadly investigated [201,202]. 

Figure 4 Structure of a cadmium thiolate of cysteine ester and a cadmium carboxylate of methionine.

Scheme 29 Stereoblock formation in the polymerization of MT initiated by cadmium thiolate of isopropyl cysteine.

The cadmium-thiolate complexes (Table 6) have the greatest known shifts to lower shielding (24). Magnetic circular dichroism indicates near tetrahedral symmetry about cadmium, and it is suggested that the greatest deshielding is from total... 

Cadmium thiolates considered here include those compounds that, if mononuclear, only involve ligation by organothiolate anions (RS ) and, if polynuclear, only contain these groups as skeletal bridging ligands. A nice review on the structural chemistry of metal thiolate complexes was published in 1986 by Dance [80],... 

Several crystal structures of cadmium-thiolate complexes with nuclearity higher than 4 can be found in the literature. For example, the octanuclear molecule [Cdg(SPhF-3)i4(DMF)6(N03)](N03) [97] (Figure 27) consists of a cubic cluster... 

CdS Nanoparticles Thermal decomposition has been one of the most efficient pathways for synthesizing CdS nanoparticles. In a typical thermolysis process, a cadmium thiolate powder is heated so as to nucleate CdS particles which are then grown to the desired size by controlled reaction of precursor molecules. Some of the major synthesis methods used are summarized in Table 2. A single source precursor made by reacting cadmium metal ions and a molecule containing the sulphur in a complexing solution of trioctylphosphine (TOP), trioctylphosphineoxide (TOPO), hexadecylamine (HDA), tetradecylamine (TDA) trioctylamine (TOA) or dodecylamine (DA) has been used to produce CdS nanoparticles [197-201]. 

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