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Congeners and their Properties

Please answer and explain where appropriate

The brominated flame retardants consist of 209 congeners with different physical-chemical properties and therefore behave differently in the environment.

Congener/ Water Solublity (mol/L)/Log KOA/Log KOW/Human BMF
4, 4'-dibromo / 6.57 x 10-7 / 8.64 / 5.86 / -
2,2',4,4'-tetrabromo / 3.04 x 10-8 / 9.80 / 6.78 / 98
2,2',4,4',5-pentabromo / 7.74 x 10-9 / 11.2 / 7.39 / 98
2,2',4,4',5,5'-hexaabromo / 7.82 x 10-11/12.15 / 8.05/ -
2,2',4,4',5,5',6,6'- decabromo / - / 13.1 / 9.9 / 8

(a) How many congeners exist in the monobromo homolog group? Draw their structures.

(b) Calculate the molecular weights of the 5 congeners listed above.

(c) What do the trends of log KOA, log KOW, and the negative log of water solubility vs. molecular weight indicate about the relationship between molecular weight and:
-solubility and mobility in water?
-potential for long range transport in air?
-hydrophobicity?

(d) Why is BMF higher for tetra and penta homologs than for deca homolog?

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General extra information about Brominated Flame Retardants:
Source: Agilent

The presence of polybrominated diphenyl ethers (PBDE) throughout the world environment has attracted the attention of scientists around the world. PBDEs are used as flame retardants in many commercial products, like textile and furniture, and in circuit boards in consumer electronics, like TVs and computers. As more and more of these abundant consumer products find their way into landfills, PBDEs have been found in our drinking water supplies (1). One alarming study predicts that the level found in human breast milk of North American women appear to double ...

Solution Summary

Poly-Brominated Diphenyl Ethers ( PBDEs ) as Congeners and their Potential Toxicity

A range of problems with regard to their structures and properties.

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