Theoretical Investigation Into The Cooperativity Effect Of Na~+for Benzonitirle Hydrate

Wastewater containing cyanide is a very toxic industrial effluent, cyanide is highlytoxic substances, which can cause great harm to the human body. Therefore, the treatment ofcyanide wastewater in recent years, especially the treatment of aromatic cyanide wastewateraroused people’s interest. The content of this paper provides a solid theoretical basis for moreeffective treatment technology of cyanide wastewater.The cooperativity effects between the H-bonding and Na+π or Na+σ interactions,thermodynamic properties and electronic structures in Na+benzonitrile H2O ternarycomplexes were investigated by using the B3LYP and MP2(full) methods with the6-311++G(2d,p) and aug-cc-pVTZ basis sets. The result shows that the influence of theNa+σ or Na+π interaction on the H-bond is more pronounced than that of the latter on theformer. The cooperativity effect appears in the Na+σ interaction complex while theanti-cooperativity effect tends to be in the Na+π system. Na+binding to benzonitrile is easierto take place in the presence of H2O. The enthalpy change is the major factor driving thecooperativity. The thermodynamic cooperativity is not always in accordance with thecooperativity effect evaluated by using the change of interaction energy. The BDE of theC–CN bond increases upon the Na+σ interaction complex formation while the decrease inthe Na+π system. The cooperativity effect correlates with Rc(NICS(1)ternary/NICS(1)binary),ΔΔδ (Δδternary–Δδbinary), and RBDE(C–CN)(BDE(C–CN)ternary/BDE(C–CN)binary), respectively. AIM(atoms in molecules) analysis confirms the existence of cooperativity.Optimize structure of H+benzonitrile H2O complexes were investigated by using theB3LYP method with the6-311++G(2d,p) basis sets. For possible reaction about generatinghydrogen, generating HCN or HNC molecule and C–C bond cleavage of ring, reactant,product, intermediate compounds and transition state were fully optimized by using theB3LYP and HandHLY methods with the6-311++G(2d,p) basis sets, and use the IRCcalculation confirmed the reactions. The rate constants are calculated using the conventionaltransition state theory(TST).In summary, this dissertation has not only provided a large amount of basic data about benzonitrile compound, but also summed up some valuable rules which are helpful to thefurther theoretical study for more effective treatment technology of cyanide wastewater.