Organometallic Chemistry

Ligand Design and Catalysis

  • Metal catalyzed transformations can be tweaked to meet the targets by tuning the coordinated ligands. Hence the focus in our group is to develop innovative catalytic transformation by careful and rational ligand design. We strive to achieve this by investigating the structural elements that control catalyst performance. Among the various ligand classes, phosphorus based ligands play a prominent role in organometallic transformations. We design phosphorus ligands with supramolecular binding motif’s (e.g. coordinative binding, hydrogen bonding) that may induce special selectivity, which would not have been possible otherwise. These ligands are then treated with metal precursors to synthesize metal complexes. In addition to the classical steric and electron effects, we investigate the effect of ligand geometry, cone angle/bite angle and symmetry, on the catalyst performance. Single crystals of the metal complexes provide further information on the various factors that might be responsible for the outcome of the catalytic transformation.
  • We then employ the thus prepared catalysts in various organometallic transformations such as hydrophosphination, hydrogenation, hydroformylation, polymerization and oligomerization. In addition to routine techniques, various modern tools such as in-situ NMR, in-situ high pressure NMR, high pressure-IR, ESI mass-spectrometry etc are employed to study the effect of catalyst on the selectivity.


Refereces:

  • Satej S. Deshmukh, Shahaji R. Gaikwad, Nilesh R. Mote, Manod M., Samir H. Chikkali, ACS Omega 2019, 4, 9502-9511.
  • Nilesh R. Mote, Samir H. Chikkali* Chem. Asian J. 2018, 13, 3623-3646 (Cover Feature).
  • Nilesh R. Mote, Ketan Patel, Dinesh Shinde, Shahaji R. Gaikwad, Vijay S. Koshti, Rajesh G. Gonnade, Samir H. Chikkali* Inorg. Chem. 2017, 56, 12448-12456.
  • Vijay S. Koshti, Shridhar H. Thorat, Ravindra P. Gote, Samir H. Chikkali*, Rajesh G. Gonnade* CrystEngComm, 2016, 18, 7078-7094.
  • Vijay S. Koshti, Nilesh R. Mote, Rajesh G. Gonnade, Samir H. Chikkali*, Organometallics, 2015, 34, 4801-4805.
  • Vijay S. Koshti, Shahaji R. Gaikwad, Samir H. Chikkali* Coord. Chem. Rev. 2014, 265, 52-73.
  • Samir H. Chikkali*, J. I. van der Vlugt*, Reek, J. N. H.* Coord. Chem. Rev. 2014, 262, 1-15.
  • Samir Chikkali, Rosalba Bellini, Bas de Bruin, J. I. van der Vlugt, Reek, J. N. H. J. Am. Chem. Soc. 2012, 134, 6607-6616.
  • Rosalba Bellini, Samir H. Chikkali, G. Berthon, Reek J. N. H. Angew. Chem. Int. Ed. 2011, 50, 7342-7345.

 

Polymers and Materials

Functional Olefin (co)polymerization

  • Metal catalyzed polymerization of ethylene and propylene is one of the extensively investigated organometallic transformations and is employed to produce more than 60 million tons of polyolefins annually. Despite this progress, insertion (co)polymerization of electron deficient vinyl monomers has remained elusive.
  • We are working on a potentially general approach to overcome present shortcomings by supramolecular interactions between the specific additional binding sites in the catalyst and the polar olefinic monomer.


Refereces:

  • Shahaji R. Gaikwad, Satej S. Deshmukh, Vijay S. Koshti, Suparna Poddar, Rajesh G. Gonnade, Pattuparambil R. Rajamohanan, Samir H. Chikkali, Macromolecules 2017, 50, 5748-5758.
  • Shahaji R. Gaikwad, Satej S. Deshmukh, Rajesh G. Gonnade, Samir H. Chikkali, ACS Macro Lett. 2015, 4, 933.
  • Samir H. Chikkali, Shahaji R. Gaikwad, Provisional Filing No. 2587DEL2014-09-11, Provisional filing date : 10th Sept.2014
  • Shahaji R. Gaikwad, Satej S. Deshmukh, Samir H. Chikkali*, J. Polym. Sci. Part A: Polym. Chem. 2014, 52, 1-6. 

 

Green and Sustainable Chemistry

Polymers from plant oils and sugars

  • Depleting natural oils reserves and growing environmental constraints have posed a new challenge and quest to discover sustainable alternatives has already began. In this context, polymers derived from alternative renewable resources are highly desirable. Plant oil derived fatty acids and sugar based bifunctional molecules are highly desirable candidates, however these have limited direct use in polymer chemistry. The aim is to develop catalytic transformations enabling the synthesis of AA or AB type monomers from plant oil derived fatty acids or sugars.


Refereces:

  • B. Rajput, U. Chander, K. Arole, F. Stempfle, S. Menon, S. Mecking, Samir H. Chikkali*, Macromol. Chem. Phys. 2016, 217, 1396. 
  • S. Pandey, Samir H. Chikkali*, ChemCatChem. 2015, 7, 3468.
  • B. Rajput, S. Gaikwad, S. K. Menon and S. H. Chikkali*, Green Chem. 2014, 16, 3810-3818.
  • Samir H. Chikkali, B. Rajput, Provisional filing No. 1386-DEL-2-13 (2013).
  • Samir Chikkali, Florian Stempfle, Stefan Mecking, Macromol. Rapid Commun. 2012, 33, 1126-1129 (Front cover of the issue)
  • Samir Chikkali, Stefan Mecking, Angew. Chem. Int. Ed. 2012, 51, 5802-5808.