161 4th International Conference, World Science Congress -2014 (WSC-2014) 16th ~ 18th December, 2014. Jadvpur University, Kolkata, India Ci 13
Xylene-bridged allylic-substituted Bis-Imidazolium Pd(II)-NHC Complex; Synthesis, structure, catalysis and DFT study G. Roymahapatraa,*, S. K. Sethb, and J. Dinda c a
Dept. of Basic Science and Humanities, Global Institute of Science and Te chnology, Haldia-721657 Department of Physics, Mugberia Gangadhar Mahavidyalaya, Purba Medinipur, West Bengal - 721425, c Dept. of Chemistry, ITM University, Turari Campus, Gwalior-474001, *Email:
[email protected] b
Earlier, various bis-NHC ligands have been reported, which are usually linked by alkenic chains be wont to form chelating complexes with metals where NHC with xylene-bridge are surprisingly rare. The allylic substituent at ‘N’ of imidazole, change the metal-organic coordination mode during reaction complex which encouraging to design Pd-complex of xylene bridge allylic substituted bisNHC ligand. 3,3'-(p-phenylenedimethylene)-bis{1-(2-methylallyl)}imidazolium bromide (L); ligand and its Palladium(II) N-hetreocyclic carbene (NHC) complex 3,3'-(p-phenylenedimethylene)bis{1-(2-methylallyl)imidazoline}palladium(II) chloride (1) of the same ligand (L) [1] has been synthesized and characterized by Ag(I)-NHC transfer method [2]. The compounds are characterized by spectroscopic techniques and micro-analytical analysis. Single crystal X-ray structure of complex 1 has been determined, shows a square planar geometry. The solid state structure of Pd(II)-NHC complex 1 is stabilized through different types of H-bond interface along with C-H-Π and Π-Π interactions, and build a supramolecular framework. Complex 1 possesses ring head to tail Π– Π stacking interactions (3.767Å) through imidazole rings. Theoretical calculation (DFT) and HOMO-LUMO orbital energy has been studied to know the stability of Pd(II) complex in syn and anti-configuration and it shows that anticonfiguration of complex 1 is energetically more stable than the syn-configuration. Complex 1 shows good catalytic activity in Suzuki–Miayura [3] coupling reactions. Referrences: [1] Samanta T, Roymahapatra G, Porto WF, Seth S, Ghorai S, Saha S, Sengupta J, Franco OL, Dinda J and Mandal SM, 2013, PLoS ONE, 8(3), e58346. [2] (a) Chiu PL, Chen CY, Zeng JY, Lu CY and Lee HM , 2005, J. Organomet. Chem., 690, 1682, (b) Lin IJB and Vasam CS, 2007, Coord. Chem. Rev., 251, 642. [3] Roymahapatra G, Giri S, Danopoulos A A, Chattaraj PK, Mahapatra A, Bertolasi V and Dinda J, 2012, Inorg. Chim. Acta., 383, 83.
