https://libjncir.jncasr.ac.in/xmlui/handle/10572/1463 2026-04-04T05:31:24Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2428 Amide Functionalized Microporous Organic Polymer (Am-MOP) for Selective CO2 Sorption and Catalysis Suresh, Venkata M.; Bonakala, Satyanarayana; Atreya, Hanudatta S.; Balasubramanian, Sundaram; Maji, Tapas Kumar We report the design and synthesis of an amide functionalized microporous organic polymer (Am-MOP) prepared from trimesic acid and p-phenylenediamine using thionyl chloride as a reagent. Polar amide (CONH) functional groups act as a linking unit between the node and spacer and constitute the pore wall of the continuous polymeric network. The strong covalent bonds between the building blocks (trimesic acid and p-phenylenediamine) through amide bond linkages provide high thermal and chemical stability to Am-MOP. The presence of a highly polar pore surface allows selective CO2 uptake at 195 K over other gases such as N-2, Ar, and O-2. The CO2 molecule interacts with amide functional groups via Lewis acid base type interactions as demonstrated through DFT calculations. Furthermore, for the first time Am-MOP with basic functional groups has been exploited for the Knoevenagel condensation reaction between aldehydes and active methylene compounds. Availability of a large number of catalytic sites per volume and confined microporosity gives enhanced catalytic efficiency and high selectivity for small substrate molecules. Restricted Access 2014-01-01T00:00:00Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2429 Flexible and Rigid Amine-Functionalized Microporous Frameworks Based on Different Secondary Building Units: Supramolecular Isomerism, Selective CO2 Capture, and Catalysis Haldar, Ritesh; Reddy, Sandeep K.; Suresh, Venkata M.; Mohapatra, Sudip; Balasubramanian, Sundaram; Maji, Tapas Kumar We report the synthesis, structural characterization, and porous properties of two isomeric supramolecular complexes of ([Cd(NH(2)bdc)(bphz)(0.5)]DMFH2O}(n) (NH(2)bdc=2-aminobenzenedicarboxylic acid, bphz=1,2-bis(4-pyridylmethylene)hydrazine) composed of a mixed-ligand system. The first isomer, with a paddle-wheel-type Cd-2(COO)(4) secondary building unit (SBU), is flexible in nature, whereas the other isomer has a rigid framework based on a -oxo-bridged Cd-2(-OCO)(2) SBU. Both frameworks are two-fold interpenetrated and the pore surface is decorated with pendant -NH2 and NN functional groups. Both the frameworks are nonporous to N-2, revealed by the typeII adsorption profiles. However, at 195K, the first isomer shows an unusual double-step hysteretic CO2 adsorption profile, whereas the second isomer shows a typical typeI CO2 profile. Moreover, at 195K, both frameworks show excellent selectivity for CO2 among other gases (N-2, O-2, H-2, and Ar), which has been correlated to the specific interaction of CO2 with the -NH2 and NN functionalized pore surface. DFT calculations for the oxo-bridged isomer unveiled that the -NH2 group is the primary binding site for CO2. The high heat of CO2 adsorption (H-ads=37.7kJmol(-1)) in the oxo-bridged isomer is realized by NH2CO2/aromatic CO2 and cooperative CO2CO2 interactions. Further, postsynthetic modification of the -NH2 group into -NHCOCH3 in the second isomer leads to a reduced CO2 uptake with lower binding energy, which establishes the critical role of the -NH2 group for CO2 capture. The presence of basic -NH2 sites in the oxo-bridged isomer was further exploited for efficient catalytic activity in a Knoevenagel condensation reaction. Restricted Access 2014-01-01T00:00:00Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2423 Synthesis, Characterization, and Modeling of a Functional Conjugated Microporous Polymer: CO2 Storage and Light Harvesting Suresh, Venkata M.; Bonakala, Satyanarayana; Roy, Syamantak; Balasubramanian, Sundaram; Maji, Tapas Kumar A Rationalization of structure and properties of amorphous porous solids at the microscopic level is essential in developing advanced materials. We delineate the structural modeling of a designed tetraphenylethene-based amorphous conjugated microporous polymer TPE-CMP (1) and its gas storage and photophysical properties. The polymer 1 exhibits high specific surface area of 854 m(2)/g. 1 showed appreciable CO2 (32.4 wt %) uptake at 195 K up to 1 atm and 31.6 wt % at 273 K up to 35 bar. The structural model of 1 obtained through computational methods is quantitatively consistent with experimental observations. The microporous structural model of 1 was further validated by a calculation of CO2 adsorption isotherm obtained through GCMC simulations. Quantum chemical calculations were employed to understand the nature of interactions of CO2 with the constituents of the framework 1. pp interaction with strength of 19 kJ/mol was observed between CO2 and the phenyl rings of TPE. 1 shows strong turn-on greenish-yellow emission due to the restriction of phenyl ring rotation of TPE node. This framework induced emission (FIE) of microporous polymer 1 is further exploited for light-harvesting applications by noncovalent encapsulation of a suitable acceptor dye, rhodamine B (RhB), in the framework. Restricted Access 2014-01-01T00:00:00Z https://libjncir.jncasr.ac.in/xmlui/handle/10572/2424 Two 3D metal-organic frameworks of Cd(II): modulation of structures and porous properties based on linker functionalities Haldar, Ritesh; Bonakala, Satyanarayana; Kanoo, Prakash; Balasubramanian, Sundaram; Maji, Tapas Kumar Two new Cd(II) based metal-organic frameworks (MOFs), {[ Cd(NH2-bdc)(bpe)] center dot 0.5EtOH}(n) (1) and {[ Cd(NO2-bdc)(azbpy)] center dot 4H(2)O} n (2) (NH2-bdc = 2-amino terephthalic acid, bpe = 1,2-bis(4-pyridyl) ethane, NO2-bdc = 2-nitro terephthalic acid, azbpy = 4,4'-azobipyridine), have been synthesized by a solvent diffusion technique and structurally characterized. Both the frameworks are constructed based on exo-bidentate pyridyl type linkers of similar length but different functionalities. Compound 1 has a 3D structure in which the -NH2 functional group of NH2-bdc is coordinated to Cd(II) and a 1D ultra-micropore accommodates ethanol guest molecules. The desolvated framework of 1 (1') is rigid as realized from the PXRD patterns and shows a type-I CO2 uptake profile with a reasonably high isosteric heat of adsorption value. Density functional theory (DFT) calculation shows that aromatic p electrons interact strongly with CO2 and the binding energy is 33.4 kJ mol(-1). Compound 2 has a two-fold interpenetrated 3D porous framework structure where pendent -NO2 groups of NO2-bdc are aligned on the pore surface. The desolvated framework (2') exhibits structural transformation and is nonporous to N-2. Smaller and gradual CO2 uptake in 2' can be attributed to the structural contraction. The solvent (H2O, MeOH and EtOH) vapour adsorption studies suggest that the pore surface of 2' is hydrophobic in nature. Restricted Access 2014-01-01T00:00:00Z