2.2.5 Green Chemistry and atom economy

Takes into account of environmental effects not just useful output with respect to input

Global impact of Science

• Green chemistry was coined in 1991 by Paul Anastas and John Warner

  • Formed the 12 principles of Green Chemistry

Atom Economy

• Efficenty of reaction

• Ratio of molar mass of isolated target product to the combined molar mass of all starting materials, catalysts, and solvens used int he reaction

atom economy $=$$\frac{\text{Molar mass of desired product}}{\text{Total Molar mass of mixture}}\cdot 100\%$

• $A + B \rightarrow C$

  • about 100% atom economy if without use of catalysts and solvents

• $A + B \rightarrow C + D$

  • Significantly lower atom economy because the desired rpoduct C, is obtained while D is product that is thrown away