氮原子电负性大，在胺基基团中氮原子有一对孤对电子，可以与质子结合，显示

Large electronegativity nitrogen atom in the amine group on the nitrogen atom with a lone pair of electrons, protons may be combined with, the basic display. Table 1 shows that the amine group with a nitrogen atom attached to the aliphatic alkyl group, the nitrogen atom electron density is increased, increasing the ability of combining with a proton, a base dissociation constant Kb increases, more alkaline, such as methylamine to piperidine Wait. Electronegative atom such as NH2NH2 in large connected -NH2, a nitrogen atom electron density is reduced, combining with a proton diminished capacity, the base dissociation constant Kb reduced, alkaline reduced. A nitrogen atom and an unsaturated bond connected to a nitrogen atom lone pair of electrons and π bond action, a nitrogen atom electron density less, in combination with a proton ability weaker base dissociation constant Kb smaller, alkaline weaker, such as aniline to pyridine [9]. Pyrrole having five-membered ring structure, five atoms on the pyrrole ring are sp2 hybridized, in the same plane, the nitrogen atom lone pair p-orbital electrons to occupy, and p orbital with four parallel and overlapping carbon atoms, form a 5 atoms, six π electron conjugated system closed, having aromatic character. Pyrrole nitrogen atom in the molecule lone pair of electrons involved in the conjugated ring system, the electron density on the nitrogen atom is relatively reduced, pyrrole nitrogen atom small basic (pKb 13.6); a hydrogen attached to the nitrogen atom in the leaving atomic form positive ions, thus weakly acidic with pyrrole, ionization constant Ka = 10-17.5

Nitrogen atoms have a large electrical negative, in the amine-based group nitrogen atoms have a pair of lone pairs of electrons, can be combined with protons, showing alkaline. Table 1 shows that the nitrogen atoms of the amine-based group are connected to the thalitalal, the density of the nitrogen atom electron cloud increases, the binding capacity of the proton swells increases, the dissocyllation constant Kb of the alkali increases, and the alkaline increase, such as metamine to thin. Connected to large electric-negative atoms such as NH2NH2-NH2, the density of nitrogen atoms' electron cloud is reduced, the binding ability with protons is reduced, the dissocystyability of alkalis is reduced, and the alkali is reduced in Kb. Nitrogen atoms are connected to unsaturated bonds, nitrogen atoms are isolated to electrons and molybdenum bonds, nitrogen atoms have less density, less binding to protons, less dissocyllative constant Kb of alkalis, and weaker alkalis, such as anphthia to radon. With a five-yuan ring structure of the crucible, the five atoms on the ring are sp2 hybrid, in the same plane, nitrogen atoms of the lone pair of electrons occupy the p track, and four carbon atoms of the p track parallel and overlapping, forming a five atoms, six electrons closed conjugate system, with aromatic. The lone-to-electrons of nitrogen atoms in the pyridoxa molecule are involved in the conjugate of the ring system, the electron density on the nitrogen atom is relatively reduced, and the alkalinity of the pyrocoan atom is small (pKb 13.6); The hydrogen atomic energy of the nitrogen atoms is connected in the form of positive ions, so the queer has a weak acidity, ionization constant Ka 10-17.5

The electronegativity of the nitrogen atom is large. In the amino group, the nitrogen atom has a pair of lone pair electrons, which can combine with the proton and show alkalinity. Table 1 shows that the nitrogen atom of amino group is connected with aliphatic alkyl group, the electron cloud density of nitrogen atom increases, the binding ability with proton increases, the dissociation constant KB of alkali increases, and the alkalinity increases, such as methylamine to piperidine. The electron cloud density of nitrogen atom decreases, the binding ability with proton decreases, the dissociation constant KB of alkali decreases, and the alkalinity decreases. The nitrogen atom is connected with the unsaturated bond, the lone pair electron of the nitrogen atom acts on the π bond, the electron cloud density of the nitrogen atom is smaller, the binding ability with the proton is weaker, the dissociation constant KB of the alkali is smaller, and the alkalinity is weaker, such as aniline to pyridine [9]. Pyrrole with five membered ring structure, five atoms of pyrrole ring are SP2 hybrid, in the same plane, the P orbit occupied by lone pair electrons of nitrogen atom is parallel and overlapped with the P orbit of four carbon atoms, forming a closed conjugation system of five and six π electrons, which is aromatic. The lone pair electrons of nitrogen atom in pyrrole molecule participate in the conjugation of the ring system, the electron density of nitrogen atom is relatively reduced, and the basicity of nitrogen atom in pyrrole is small (PKB 13.6); the hydrogen atom energy connected with nitrogen atom leaves in the form of positive ion, so pyrrole has weak acidity, and the ionization constant Ka = 10-17.5<br>