Rare intermolecular M⋯H–C anagostic interactions in homoleptic Ni(ii)–Pd(ii) dithiocarbamate complexes. (20th May 2015)

• Record Type: Journal Article
• Authors: Yadav, Manoj Kumar; Rajput, Gunjan; Prasad, Lal Bahadur; Drew, Michael G. B.; Singh, Nanhai
• Is Part Of: New journal of chemistry. Volume 39:Number 7(2015:Jul.)
• Page Start: 5493
• Page End: 5499
• Publication Date: 2015-05-20
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c5nj00452g
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : New Ni(ii )–Pd(ii ) dithiocarbamates have been fully characterized;1 exhibits rare C–H⋯Ni intermolecular anagostic interactions, whereas2 shows C–H⋯Pd hydrogen bonding–anagostic interactions. Abstract : New functionalized homoleptic dithiocarbamates of the form [M(L)2 ] (M = Ni(ii ), L = L1, N -(3-methoxybenzyl)- N -(methylbenzyl)dithiocarbamate (1 ), L3, N -(3, 4, 5-trimethoxybenzyl)- N -(3-methylpyridyl)dithiocarbamate (3 ), L4, N -(4-methoxybenzyl)- N -benzyldithiocarbamate (4 ); Pd(ii ), L2, N -( N ′-methyl-2-pyrrole)- N -benzyldithiocarbamate (2 )) have been synthesized and characterized by microanalysis and their structures have been investigated using X-ray crystallography. All the four structures are centrosymmetric with the metal located in a square plane with minor distortions, Pd(ii ) greater than Ni(ii ). The crystal structures of1 and2 revealed the existence of unique intermolecular C–H⋯M (Ni, Pd) anagostic interactions between the methylene hydrogen atom on the ligand substituents and the metal centres and these enable the formation of 1-D polymeric chains. Particularly, geometric parameters (Pd⋯H–C = 2.61 Å; ∠Pd⋯H–C = 173°) for the C–H⋯Pd interactions in2 are at the border of anagostic and hydrogen bonding. By contrast, 4 shows interactions between the methylene hydrogen atom and the CS2 Ni ring rather than the metal alone, while the interaction in3 is intermediate between the two aforementioned types. These interactions are not shown in solution as revealed by their 1 H NMR studies. DFT calculations have been performed to analyse these rare interactions.1, 3 and4 are weakly conducting, σ rt = 10 −10 –10 −12 S cm −1, and show semiconductor behaviour in the 313–373 K range.