Major Research Areas

  • Advanced functional microporous materials like Metal-organic Frameworks (MOFs), Porous organic polymers (POPs), Metal-organic polyhedras (MOPs), Composite materials (CMs), Supramolecular-organic Frameworks (SOFs), Hydrogen-bonded Organic Frameworks (HOFs) etc. 
  • Multifunctional materials, Supramolecular chemistry, Crystal engineering.
  • Chemical sensors, Ion exchange materials, pollutant capture, adsorptive separation, Fuel-cell membrane materials etc. 
  • Materials for Chemical industry, Energy and Environmental applications.
In my research group we are mainly working on development and functional studies of various advanced microporous materials like Metal-organic Frameworks (MOFs), Covalent-organic Frameworks (COFs), Supramolecular-organic Frameworks (SOFs), Hydrogen-bonded Organic Frameworks (HOFs) etc for chemical industry, energy and environmental applications.

We seek to correlate structural features with physical properties and to design synthetic strategies to prepare functional materials and to tune their structures and properties. We use synthetic methods from both inorganic and organic chemistry to prepare novel types of material and then use a wide variety of techniques to study their structure and properties. Using suitable organic ligands (predesigned by organic synthetic methods or commercially available ligands) we synthesis new self-assembled materials. Once the structure of new compound is determined by X-ray single crystal diffraction, the obtained bulk materials are characterized by different physical techniques that include powder X-ray diffraction (PXRD), thermo gravimetric analysis (TGA), elemental analysis, vibrational spectroscopy (IR), sorption, etc. The synthesized materials are used for functional studies like chemical separation, gas storage, magnetism, heterogeneous catalysis, conductivity, sensor etc.

Representative Publications and further reading:
  • Coord. Chem. Rev. 2019395, 146-192.Web Link
  • Coord. Chem. Rev. 2016307313-341 (Web Link)
  • Accounts of Chemical Research 201750, 2457-2469. (Web Link)
  • Chem. Soc. Rev. 2017, 46, 3242-3285. (Web Link)
  • Coord. Chem. Rev. 2018, 367, 82-126. (Web Link

Representative Research Areas

Water Stable and Luminescent-MOF Based Environmental Applications:

1. Luminescent-MOF Based Chemical Sensors

MOF as a chemical sensor has been employed for multiple applications like explosive detection, in vivo neurotransmitter sensing and ion recognition. Chemically stable Zr(IV) and carboxylate based porous fluorescent MOF with free Lewis basic functional groups (like amine, pyridyl ) has been developed for highly selective nitro explosive detection in aqueous phase. A bio-compatible Zr(IV) and carboxylate based MOF based turn-on probe for detection of gasotransmitter H2S in live cells has also been established in our lab. Several other fluorphore-based MOF probes are being studied for diverse sensing and detection purposes, accompanied with high selectivity and sensitivity. 

Representative Publications and further reading:
  • Chem. Eur. J. 201622, 864-868 (Web Link)
  • Chem. Eur. J. 201521, 9994-9997 (Web Link)
  • Chem. Eur. J. 201521, 965 -969 (Web Link)
  • Chem. Commun. 2015, 51, 6111-6114 (Web Link)
  • Chem. Commun. 2014, 50, 8915-8918 (Web Link)
  • Angew. Chem. Int. Ed. 2013, 52, 2881-2885 (Web Link)
  • Chem. Soc. Rev. 2017, 46, 3242-3285. (Web Link)

2. Sequestration of Environmentally Toxic Pollutants

A number of new cationic MOFs are being synthesized from N-donor based neutral linkers, which via intermediacy of anion exchange and fluorescence/IR based detection techniques, are being employed for selective anion recognition and detection phenomena. Interesting anion-responsive tunable luminescent properties have been the signature attributes for this class of compounds. These compounds have also been sought for the capture of toxic oxyanions in aqueous medium. 

Representative Publications and further reading:
  • Angew. Chem. Int. Ed.  2020, 59, 7788 (Web Link)
  • Angew. Chem. Int. Ed. 201655, 7811-7815 (Web Link)
  • Dalton Trans. 2016, 45, 4060-4072 (Web Link)
  • Inorg. Chem. 201554, 110-116 (Web Link)
  • Chem. Eur. J. 2014, 20, 12399-12404 (Web Link)
  • Inorg. Chem. 2014, 53, 12225-12227 (Web Link)
  • Angew. Chem. Int. Ed. 201352, 998-1002 (Web Link)

Industrially Relevant Hydrocarbon Separation 

Separation of hydrocarbon species holds great importance in industrial applications. From the application-perspective, the separation of liquid phase hydrocarbons, especially those having related physical properties and similar molecular sizes is highly challenging for industrial applications. Adsorption-based separation seems the best alternative against the expensive and energy-intensive azeotropic and extractive distillation methods for achieving such separation. In our lab, functional MOFs are being designed and developed for the separation of industrially vital monomers like benzene, p-xylene and styrene from the congener product streams. 

Representative Publications and further reading:
  • Scientific Reports 2014, 4, 5761 (Web Link)
  • Chem. Eur. J. 201420, 15303-15308 (Web Link)
  • Inorg. Chem. 201554, 4403-4408 (Web Link)
  • Chem. Eur. J. 201521, 7071-7076 (Web Link)
  • Chem. Commun. 201551, 15386-15389 (Web Link)
  • Chem. Commun. 201652, 8215-8218 (Web Link)
CO2 Storage and Separation

The field of developing new-generation MOF materials for COstorage and separation has tremendously evolved over the last decade as one of the frontiers to tackle energy and environmental issues concerning the green-house gas COemission. We are working in this field to synthesize porous MOFs with electron-rich pore surface for selective CO2 uptake over N2, H2, Ar, CH4 gases. We are also in the process of utilizing the dual functionalities of open metal sites and secondary functionalities (like amine, hydroxy) present in MOFs for achieving selective CO2 capture over potentially competing flue gases (Fig. b). 

Representative Publications and further reading:
  • Beilstein J. Org. Chem. 2016, 12, 1981-1986 (Web Link)
  • ChemPlusChem 2016,  81, 702-707 (Web Link)
  • Inorg. Chem. 201251, 572-576 (Web Link)

Stimulus-Responsive MOFs

The presence of flexible components makes MOFs as suitable stimuli-responsive materials. The responsive building blocks can be modulated to suit the specific demands and yet retain the porous character of the system. The external stimuli which can inflict changes to the framework or provide a secondary signal range from physical stimuli like light and heat to chemical species like pH and moisture. We are keenly interested in exploring this aspect of MOFs to develop compounds for applications of molecular recognition via luminescent/electrical signalling pathways.   

Representative Publications and further reading:
  • Chem. Asian J. 2014, 9, 2358-2376 (Web Link)

Superhydrophobic Porous Materials

Marine oil-spillage is seeking significant research attention in recent years owing to the severe hazards posed by such incidents to both aquatic and non-aquatic biota. Several methods are being sought and developed to overcome such spills in a short time and efficiently. In this regard development of hydrophobic porous materials as oil absorbents has caught the attention. The relative ease of design strategies and flexibility at the molecular level bestows porous crystalline materials an added advantage. We are currently engaged in developing hydrophobic materials which function as aqueous phase oil sorbents. 

Representative Publications and further reading:
  • Chem. Eur. J. 2016, 22 10937-10943 (Web Link)

Fuel Cell Membranes Materials

Fuel cells have shown great potential to produce energy in higher efficiencies with no environmental pollution. Hand OH-conduction properties of MOFs evolved as an outcome of some design-principle, coupled with those subsequent to post-synthetic modification (PSM) are currently being studied for intriguing revelation of high proton conductivity and chemical stability features in both anhydrous and humidified conditions. 

Representative Publications and further reading:
  • Angew. Chem. Int. Ed. 201655, 10667-10671 (Web Link)
  • Chem. Commun. 201652, 8459-8462 ( Web Link)
  • Inorg. Chem. 201554, 5366-5371 (Web Link)
  • Angew. Chem. Int. Ed. 201453, 2638-2642 (Web Link)

Magnetic Materials

Single molecule magnets (SMMs) and Single chain magnets (SCMs) have been regarded as important classes of compounds, derived from coordination chemistry-aided apposite design principles.  Stemming from chelating ligands, mostly oxygen-donors as well as, mixed (N- and O- donating) schiff base linkers, coupled with oxophilic lanthanide ions having large unquenched orbital angular momentum, an overall increase in the magnetic anisotropy values for the concerned Ln(III) homometallic/ 3d-4f heterometallic complexes are manifested. These lead to slow magnetic relaxation guided SMM behaviours of these complexes. Also we are currently pursuing the development of materials which can respond to magnetic stimulus. Such compounds exhibiting spin transitions on application of external fields are promising candidates for several important applications. 

Representative Publications and further reading:
  • Inorg. Chem. 201655, 11283−11298 (Web Link)
  • Inorg. Chem. Front. 2015, 2, 854-859 (Web Link)
  • Inorg. Chem. 2014, 53, 7554-7560 (Web Link)
  • Inorg. Chem. 2012, 51, 9159-9161 (Web Link)
  • Dalton Trans. 41, 7695-7699 (Web Link)