Synthesis, structure and property of diorganotin N‐[(3‐methoxy‐2‐oxyphenyl)methylene]tyrosinates

Abstract

Five new diorganotin N‐[(3‐methoxy‐2‐oxyphenyl)methylene] tyrosinates, R2Sn[2‐O‐3‐MeOC6H3CH=NCH (CH2C6H4OH‐4)COO] (R = Me, 1; Et, 2; Bu, 3; Cy, 4; Ph, 5), have been synthesized and characterized by elemental analysis, IR, NMR (1H, 13C and 119Sn) spectra, and the X‐ray single crystal diffraction. In non‐coordinated solvent, complexes 1–5 have penta‐coordinated tin atom. In the solid state, 1–3 are centrosymmetric dimmers in which each tin atom is seven‐coordinated in a distorted pentagonal bipyramid, and 4 displays discrete molecular structure with distorted trigonal bipyramidal geometry, and the tin atom of 5 is hexa‐coordinated and possess the distorted octahedral geometry with a coordinational methanol molecule. The intermolecular O‐H⋅⋅⋅O hydrogen bonds in 1–4 link molecules into the different one‐dimensional supramolecular chain with R22 (30) or R22 (20) macrocycles, and the molecules of 5 are joined into a two‐dimensional supramolecular network containing R44 (24) and R44 (28) two macrocycles. Bioassay results against human tumour cell HeLa indicated that 3‐5 belonged to the efficient cytostatic agents and the activity decreased in the order 4>3>5>2>1. The fluorescence determinations show the complexes may be explored for potential luminescent materials.

Synthesis, structural characterization and cytotoxic activity of triorganotin 5‐(salicylideneamino)salicylates

“…The signal assigned to azomethine proton CH═N lies in the range 8.62–8.66 ppm. The absence of spin–spin coupling between the azomethine proton and the tin nucleus, 3 J ( 119 Sn– 1 H), confirms the azomethine nitrogen atom is not coordinated to tin atom in any of the complexes . The proton signals of phenyl groups display the usual complex pattern in the region 6.88–7.93 ppm.…”

“…We have recently focused on the synthesis and cytotoxic testing of organotin complexes of carboxylate ligand‐containing Schiff bases . Schiff bases are easily prepared from condensation reaction of salicylaldehyde derivatives with primary amines.…”

“…Variation of both the starting salicylaldehyde and the primary amine provides a synthetic strategy that readily allows for fine‐tuning of the physicochemical properties of the Schiff base ligand and hence the corresponding organotin complexes. N ‐Salicylidene‐α‐amino acid, a Schiff base derived from α‐amino acid and salicylaldehyde, displays different modes of coordination to tin atoms . The triorganotin complexes of the ligand showed significant cytotoxic activity against some cancer cells …”

“…To our knowledge, the organotin complexes of this Schiff base carboxylate ligand have not been reported in the literature. In order to expand on our previous work and to explore the effect of alkyl bound to tin and the ligand on the molecular structure and cytotoxic activity of such organotin complexes, we synthesized some new triorganotin 5‐(salicylideneamino)salicylates ( 1a – 1c and 2a – 2c ), namely [5‐(3‐X‐2‐HOC 6 H 3 CH═N)‐2‐HOC 6 H 3 COO]SnR 3 (X = H, 1 ; CH 3 O, 2 ; R = Ph, a ; Cy, b ; CH 2 C(CH 3 ) 2 Ph, c ), and determined their crystal structures and in vitro cytotoxicity.…”