Nitrogen containing microporous polymers, DMP-I and DMP-II, were synthesized by a condensation reaction using N,N′-(1,4-phenylenebis(methanylylidene)) bis(benzene-1,4-diamine) for the selective CO2 capture. These polymers have moderate surface area and pore size distribution. The prepared polymers are suitable for CO2 capture because of the higher number of Lewis basic sites. The interactions between the polarized groups and gas molecule increase the CO2 uptake of 8.7 wt.% at one bar, irrespective of surface area. Furthermore, these polymers exhibit high stability and resistant toward many solvents including water. The breakthrough experiments were carried out to investigate the selectivity potential of the polymers. In addition, the adsorbate-adsorbent interactions are highly reversible and hence these polymers are anticipated to be good sorbent.