New paper published in Nature Communication. This highly collaborative work (spearheaded by Dr. Gündoğ Yücesan) presents polyphosphonate covalent organic frameworks (COFs) constructed via P-O-P linkages, synthesized through a one-step condensation reaction. This process involves heating a hydrogen-bonded precursor made from phenylphosphonic acid and porphyrin, without chemical reagents. At temperatures above 210 °C, the COF transforms into an amorphous microporous structure due to P-O-P bond oligomerization, confirmed by ³¹P NMR. The COF shows excellent stability in water, water vapor, and in 0.5 M Na₂SO₄ electrolyte, filling a gap in COF literature for stable, microporous materials. Additionally, its narrow pores effectively capture CO₂, with a sustainable synthesis route.