Tw on ew chemically stable triazine-and phenylcore-based crystalline porous polymers (CPPs) have been synthesized using as ingle-step template-free solvothermal route.U nique morphological diversities were observed for these CPPs [2,3-DhaTta (ribbon) and 2,3-DhaTab (hollow sphere)] by simply altering the linker planarity.Adetailed time-dependent study established as ignificant correlation between the molecular level structures of building blocks with the morphology of CPPs.M oreover,aDFT study was done for calculating the interlayer stacking energy,w hich revealed that the extent of stacking efficiency is responsible for governing the morphological diversity in these CPPs.Twodimensionalcrystallineporouspolymers(CPPs),including covalent organic frameworks (COFs) [1] and covalent triazine frameworks (CTFs), [2] are porous materials constructed by covalently linked light elements,such as C, N, O, H, B, and Si. These materials have triggered substantial research interest because of their extensive applications in molecular storage, [3] catalysis, [4] sensing, [5] and opto-electronics.[6] However,the overall properties of such porous materials do not rely only on their composition, structure,and porosity, but also on their nanoscale morphologies.[7] Therefore,a n explicit understanding of the morphology-modulation with respect to their constituents is required.[8] To achieve such am olecular level understanding, herein we report two CPPs that self-assemble to ribbon and hollow spherical [9] morphologies upon crystallization in as ingle step without any templating agents.Hollow spherical structures are considered to be ah ighly important morphology in polymeric materials owing to several potential applications.H owever,t heir existence is extremely rare and often require the usage of templating agents.[10] Thei ntermediates responsible for producing these above morphologies were prepared at different time intervals to understand the mechanism for the formation of the final morphology (at 72 h).TheC PPs reported here show high crystallinity as revealed from their PXRD patterns (Figure 1). Ahigh intense peak at 2.88 8 (2q)f or 2,3-DhaTta and 2,3-DhaTab (Figure 1e and 1f,r espectively) appear owing to the strong reflections from the 100 planes.2,3-DhaTta and 2,3-DhaTab show other minor peaks at 4.9, 5.7, 7.5, and 9.98 8 (2q)o wing to the reflections from the 110, 200, 120, and 220 planes,r espectively.P eaks at 268 8 (2,3-DhaTta) and 25.88 8 (2,3-DhaTab) correspond to their 001 plane reflections.T he d-spacing values between the 001 planes were used to calculate the p-p stacking distances between vertically stacked CPP layers [3.3 and 3.4 inthe respected CPPs].The high crystallinity of these CPPs is attributed to the presence of strong intramolecular OÀH···N hydrogen bonding [11] interactions between the imine nitrogen and the hydroxy functionality of the aldehyde core,w hich is influential in keeping the phenyl rings in one plane and increases stacking interactions within adjacent CPP layers.T og et an overview...