Greener

The a2oxy and nitro groups in Direct YeUow 11 are reduced to a2o and amino groups in Direct Orange 15. Direct YeUow 6 (Cl 40006) (14) is a greener and brighter shade of yeUow than Direct YeUow 11 and is made by reductive a2o formation from 4,4 -dinitro-2,2 -stilbenedisulfonic acid to an a2o and a2oxy dye. 

Nearly all dye manufacturers use letters and numerals in the names of their products to define the hue. Thus B is blue G, yellow (gelb in German) or green R, red and Y, yellow. Numerals, ie, 2G (or GG), 3G, 4G, etc indicate, in this case, a successively yellower or greener shade. Occasionally, suffixed letters are used to feature other properties such as solubiHty, lightfastness, brightness, and use on synthetic fibers. 

Cl Acid Blue 40 (119) has a greener and somewhat duller shade than the parent dye (ie. Cl Acid Blue 25) (118), which is considered to be due to the electronic effect of the i ra-acetylamino group. 

Finally, an equally pressing need is for processes that are more environmentally friendly than those that currently use chromates, volatile solvents, etc. This is an area where the recently developed scientific tools described in this and other chapters will play a major role in assuring that the results are not only greener but are also just as effective or more so than currently used methods. 

J. G. Huddleston, G. A. Broker, H. D. Willauer, R. D. Rogers, in Green (or greener) industrial applications of ionic liquids. , ACS Symposium Series, in press. 

Many transition metal complexes dissolve readily in ionic liquids, which enables their use as solvents for transition metal catalysis. Sufficient solubility for a wide range of catalyst complexes is an obvious, but not trivial, prerequisite for a versatile solvent for homogenous catalysis. Some of the other approaches to the replacement of traditional volatile organic solvents by greener alternatives in transition metal catalysis, namely the use of supercritical CO2 or perfluorinated solvents, very often suffer from low catalyst solubility. This limitation is usually overcome by use of special ligand systems, which have to be synthesized prior to the catalytic reaction. 

Metzger, P. R., Vrijhoef, M. M. A. and Greener, E. H. Corrosion Resistance of Three High-Palladium Alloys , Dental Materials, 1, 177-179 (1985)... 

The literature contains a number of studies on the susceptibility of the cobalt-based alloys to pitting corrosion. In-vitro studies conducted by Mueller and Greener , involving static conditions, revealed no evidence of pitting having occurred. Syrett and Wing ", utilising cyclic polarisation analyses, observed that neither as-cast nor annealed Co-Cr-Mo alloy demonstrated hysteresis loops in their cyclic polarisation curves. They... 

Mueller, H. J. and Greener, E. H., Polarization Studies of Surgical Materials in Ringer s Solution , Journal of Biomedical Materials Research, 4, 29-41 (1970)... 

The gradual transition towards the biobased economy brings opportunities for developing countries to leapfrog beyond the petroleum era and into a cleaner, greener and more renewable future based on biotechnology knowledge. 

Probably the most fundamental problem facing the development of greener products and processes is the measurement of progress and the development of appropriate methods for comparison of alternatives. In many instances it will be obvious that improvements have been made, for example when a toxic material is replaced by a non-toxic alternative, keeping all other process conditions essentially the same, or when the energy requirement of a process is reduced. 

Review a recent synthetic reaction you have carried out in the laboratory. Write a balanced equation for the reaction(s) and calculate the atom economy. From your experimental results calculate the Yield, E-factor and Effective Mass Yield (ignoring any water used). Identify ways in which this reaction could be made greener. 

Emerging Greener Technologies and Alternative Energy Sources... 

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