Exploiting the versatility of pyridyl ligands for the preparation of diorganotin (IV) adducts: spectral, crystallographic and Hirshfeld surface analysis studies

Abstract

Diorganotin (IV) complexes SnR 2 X 2 (R = Me, Ph; X = Cl, NCS) form a series of versatile complexes when react with bidentate substituted pyridyl ligands. The reaction of dimethyltin dichloride with 5,5′-dimethyl-2,2′-bipyridine (5,5′-Me 2 bpy) resulted in the formation of [SnMe 2 Cl 2 (5,5′-Me 2 bpy)] (1). Moreover, the reaction of SnMe 2 (NSC) 2 with 4,4′-di-tert-butyl-2,2′-bipyridine (bu 2 bpy), 1,10-phenanthroline (phen) and 4,7-diphenyl-1,10-phenanthroline (bphen) affords the hexa-coordinated complexes [SnMe 2 (NCS) 2 (bu 2 bpy)] (2), [SnMe 2 (NCS) 2 (phen)] (3) and [SnMe 2 (NCS) 2 (bphen)] (4), respectively. The resulting complexes have been characterized using elemental analysis, IR, multinuclear NMR ( 1 H, 13 C, 119 Sn) and DEPT-135°NMR spectroscopy. On the other hand, the reaction of diphenyltin dichloride with 2,2′-biquinoline (biq) and 4,7-phenantroline (4,7-phen) led to the formation of polymeric complexes of [SnPh 2 Cl 2 (4,7-phen)] n (5) and [SnPh 2 Cl 2 (biq)] n (6). The NMR spectra, however, reveal the ligand lability in solution and suggest a coordination number of 5. The X-ray crystal structures of complexes [SnMe 2 Cl 2 (5,5′-Me 2 bpy)] (1), [SnMe 2 (NCS) 2 (bu 2 bpy)] (2) and [SnMe 2 (NCS) 2 (bphen)] (4) have been determined which reveal that the geometry around the tin atom is distorted octahedral with trans-[SnMe 2 ] configuration. Interestingly, the crystal structure of (H 2 biq) 2 [SnPh 2 Cl 4 ]•2CHCl 3 (7) was characterized by X-ray crystallography from a chloroform solution of [SnPh 2 Cl 2 (biq)] n (6) indicating the formation of doubly protonated [H 2 biq] + and [Ph 2 SnCl 4 ] 2− which are stabilized by a network of hydrogen bonds with a feature of trans-[SnPh 2 ]. The 3D Hirshfeld surface analysis and 2D fingerprint maps were used for quantitative mapping out of the intermolecular interactions for 1, 2, 4 and 7 which show the presence of π-π and hydrogen bonding interactions which are associated between donor and acceptor atoms (N, S, Cl) in the solid state.

Use of highly stable phosphonate coordination polymers as adsorbents for wastewater

“…Strong bands appear also in the FTIR range 700–850 cm −1 , being associated with the elongation vibration in the plane of the C–H bonds from the heterocyclic rings of phenanthroline and imidazole. [ 30,31 ]…”