Читать книгу Functional Metal-Organic Frameworks - Lida Hashemi, Ali Morsali - Страница 18

Amine is among the frequently applied organic functional groups in the structure of functional MOFs (FMOFs). Although, the chemistry of amine is simple, it is useful and effective. The chemistry of amine is dominated by the non-bonding electron pair on nitrogen atom and positively charged hydrogen atom.

The electrostatic potential map for the van der Waals surface of amine function reveals localization of negative charge on N atom due to high electronegativity of N atom engaged in N‒H bond and its non-bonding electrons. In this view, amine can (as Lewis basic site) interact with Lewis acid species. Also, it can accept one proton from Brønsted acid to form ammonium cations. Moreover, through nitrogen atom, amine group can act as hydrogen bond acceptor site. In addition, accumulation of negative charge on nitrogen atom enables it to engage with polar and quadruple molecules.

Another characteristic of amine function is revolved around H atom(s). Since these H atoms are positively charged, they can participate in a hydrogen bonding. Overally, amine function can interact as both hydrogen bond donor and hydrogen bond acceptor sites.