Coloration anionic materials

Mono- and Dinuclear Compounds. The pentacarbonyl is a starting material for mononuclear ruthenium carbonyl complexes. As outlined in Scheme 3, reduction with sodium in liquid ammonia yields a pale-colored anion solution (5),... 

Acid dyes are used for coloring nylon, wool, and certain other natural polymers. They are fairly low molecular weight (typically 300-500 g/mol) anionic materials, nsually the sodium salts of sulfonic acids. 

Figure 27 Photopolymerization of the precursor with an embedded butadyine moiety leads to a blue-colored polydiacetylene material (a) analyte binding to the receptor or affinity moiety (red pentagon) results in a change in the polydiacetylene conjugated backbone and shift of absorption spectra from blue to red and (b) photographs of wells comprising solution Zn(dipicolylamine)2 containing liposome (0.25 mM) and various sodium salts anions (0.25 mM) in HEPES buffer, pH = 7. (Adapted from Ref. 126. Wiley-VCH, 2011.)...

Molybdate orange and red are pigments (qv) that contain lead(II) molybdate [10190-33-3], PbMoO, formulated in mixed phases with PbCrO and PbSO. The mixed phase is more intensely colored than any of the component phases. Concerns about lead content are lessening the use of these materials (see also Paint). Various organic dyes are precipitated with heteropolymolybdates. This process allows the fixation of the dye in various fabrics. The molybdenum anion generally imparts light stabiHty to the colorant as weU (91). 

AH latex compounds should contain at least 5 phr of zinc oxide. This is needed to absorb evolved hydrochloric acid either in the compound or finished part. A larger amount should be considered if the part contains or is in contact with acid-sensitive materials such as cotton cloth. Magnesium oxide may destabilize anionic soap systems, and is avoided for that reason. The compound should also contain two parts of an antioxidant, and consideration should be given to the need for a uv screen in light-colored products. 

Heating of certain alkali halides with elemental sulfur also produces colored materials containing the anions 82 or 83 which replace the corresponding halide ions. For example, NaCl and KI crystals when heated in the presence of sulfur vapor incorporate di- and trisulfide monoanions [116-119] which can be detected, inter alia, by resonance Raman spectroscopy [120, 121] ... 

The fabrication of lasers based upon color centers adds a further dimension to the laser wavelengths available. Ordinary F centers do not exhibit laser action, but F centers that have a dopant cation next to the anion vacancy are satisfactory. These are typified by FLi centers, which consist of an F center with a lithium ion neighbor (Fig. 9.26a). Crystals of KC1 or RbCl doped with LiCl, containing FLi centers have been found to be good laser materials yielding emission lines with wavelengths between 2.45 and 3.45 p,m. A unique property of these crystals is that in the excited state an anion adjacent to the FLi center moves into an interstitial position... 

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