Synthesis and Characterization of Some Triphenyltin(IV) Complexes from Sterically Crowded [((E)-1-{2-Hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]acetate Ligands and Crystal Structure Analysis of a Tetrameric Triphenyltin(IV) Compound

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Five new organotin(IV) complexes of composition [Bz 2 SnL 1 ] n (1), [Bz 3 SnL 1 HÁH 2 O] (2), [Me 2 SnL 2 ÁH 2 O] (3), [Me 2 SnL 3 ] (4) and [Bz 3 SnL 3 H] n (5) (where L 1 = (2S)-2-{[(E)-(4-hydroxypentan-2-ylidene)]amino}-4-methylpentanoate, L 2 = (rac)-2-{[(E)-1-(2hydroxyphenyl)methylidene]amino}-4-methylpentanoate and L 3 = (2S)-or (rac)-2-{[(E)-1-(2-hydroxyphenyl)ethylidene]amino}-4methylpentanoate) were synthesized and characterized using 1 H NMR, 13 C NMR, 119 Sn NMR and infrared spectroscopic techniques. The crystal structure of 2 reveals a distorted trigonal-bipyramidal geometry around the tin atom where the oxygen atoms of the carboxylate ligand and a water ligand occupy the axial positions, while the three benzyl ligands are located at the equatorial positions. On the other hand, the analogous derivative of enantiopure L 3 H (5) consists of polymeric chains, in which the ligandbridged tin atoms adopt the same trans-Bz 3 SnO 2 trigonal-bipyramidal configuration and are now coordinated to a phenolic oxygen atom instead of H 2 O. In 2, the OH hydrogen of the ketoimine substituent has moved to the nearby nitrogen atom while in the salicylidene derivative 5, the OH is located almost midway between the phenolic oxygen atom and the nitrogen atom of the C¼N group. For the dibenzyltin derivative 1, a polymeric chain structure is observed as a result of a long intermolecular SnÁÁÁO bond involving the exocyclic carbonyl oxygen atom from the tridentate ligand of a neighbouring tin-complex unit. The tin atom in this complex has distorted octahedral coordination geometry. In contrast, the racemic dimethyltin(IV) complexes 3 and 4 display discrete monomeric structures with a distorted octahedral-and trigonal-bipyramidal geometry, respectively. The structures show that the coordination mode of the Schiff base ligand depends primarily on the number of bulky benzyl ligands (R) at the tin atom, as indeed found in the structures of related complexes where R = phenyl. With three bulky R groups, the tridentate chelating O,N, O coordination mode is preferred, whereas with fewer or less bulky R ligands, only the carboxylate and hydroxy groups are involved, which leads to polymers. Larvicidal efficacies of two of the new tribenzyltin(IV) complexes (2 and 5) were assessed on the second larval instar of Anopheles stephensi mosquito larvae and compared with two triphenyltin(IV) analogues, [Ph 3 SnL 1 H] n and [Ph 3 SnL 3 H] n . The results demonstrate that the compounds containing Sn-Ph ligands are more effective than those with Sn-Bz ligands.

Section: Introductionmentioning

confidence: 99%

Organotin(IV) complexes derived from proteinogenic amino acid: synthesis, structure and evaluation of larvicidal efficacy on Anopheles stephensi mosquito larvae

Baul

Kehie

Höpfl

et al. 2016

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“…In the structure, there are intramolecular hydrogen bonds, N─H···O and O─H···O, involving the imino N(1)─H(1) and phenolic O(3) atom, and phenolic O(4)─H(4) and carboxylate O(1) atom (Table ). A analogous triphenyltin tetrameric macrocycle has been found in triphenyltin [(2‐hydroxy‐5‐[( E )‐2‐phenyl‐1‐diazenyl]phenylmethylidene)amino]acetate . In this example, the Schiff base carboxylate ligand bridges adjacent tin atoms via a carboxylate O atom and a phenoxide O atom to form a 36‐membered ring in the macrocyclic tetramer.…”

Section: Resultsmentioning

confidence: 89%

“…Complexes 1a – 1c and 2a – 2c were prepared from the one‐pot reaction of triorganotin hydroxide, 5‐aminosalicylic acid and salicylaldehyde (or 3‐methoxysalicylaldehyde) in a 1:1:1 molar ratio in benzene–ethanol (3:1, v/v) mixed solvent with yields of 80–93% (Scheme ). Compared with the two‐step method in which the Schiff base carboxylic acid ligand needs to be first prepared, this preparation process is simpler and highly efficient. These products obtained from the reaction are orange crystalline solids, and are stable in air and soluble in common organic solvents such as chloroform, methanol and acetone.…”

Section: Resultsmentioning

confidence: 99%

“…In the solid state, four basic motifs have been observed for (RCOO)SnR 3 : discrete with four‐ or five‐coordinate tin atom, one‐dimensional chain with five‐coordinate tin atom, and macrocycle with five‐coordinate tin atom . With a carboxylate ligand containing an additional heteroatom (N or O), the triorganotin carboxylates usually generate chain or cyclic structures in the form of bridging two adjacent tin centers by the heteroatom and the carboxylate oxygen atom …”

Section: Introductionmentioning

confidence: 99%

“…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 …”

Section: Introductionmentioning

confidence: 99%

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

Liu

Lin

Liu

et al. 2019

Six new triorganotin complexes (1a–1c and 2a–2c) of 5‐(salicylideneamino)salicylic acid, [5‐(3‐X‐2‐HOC6H3CH═N)‐2‐HOC6H3COO]SnR3 (X = H, 1; CH3O, 2; R = Ph, a; Cy, b; CH2C(CH3)2Ph, c), have been synthesized by one‐pot reaction of 5‐aminosalicylic acid, salicylaldehyde and triorganotin hydroxide and characterized using elemental analysis and infrared and NMR (1H, 13C and 119Sn) spectra. The crystal structures of 1a, 1b, 2a·CH3OH, 2b·CH3OH and 2c·CHCl3 have been determined using single‐crystal X‐ray diffraction. In non‐coordinated solvent CDCl3, the tin atoms in the complexes are all four‐coordinated. In the crystalline state, these compounds adopt a four‐ or five‐coordination mode. Complex 1a exhibits a 44‐membered macrocyclic tetrameric structure with trigonal bipyramidal geometry around the tin atoms in which the axial positions are occupied by the oxygen atom of carboxylate group of the ligand and the phenolic oxygen atom from the adjacent ligand. The coordination geometry of tin atom in 1b and 2c·CHCl3 is a distorted tetrahedron shaped by three carbon atoms of alkyl groups and a carboxylate oxygen atom of the ligand. In 2a·CH3OH and 2b·CH3OH, the tin atom has a distorted trans‐C3SnO2 trigonal bipyramidal geometry formed by three alkyl groups, a monodentate carboxylate group and a coordinated methanol molecule. The molecules of 2a·CH3OH and 2b·CH3OH are linked via O─H···O hydrogen bonds into a one‐dimensional supramolecular chain and a centrosymmetric R44(22) macrocycle, respectively. Bioassay results against two human tumor cell types (A549 and HeLa) show the complexes are efficient cytostatic agents and may be explored as potential antitumor drugs.

Synthesis, structural characterization, and properties of triorganotin complexes of Schiff base derived from 3‐aminobenzoic acid and salicylaldehyde or 2,4‐pentanedione

Chen

Wang

Qiu

et al. 2020

Six new triorganotin 3‐(salicylideneamino)benzoates (1a–1c) and 3‐(4‐oxo‐2‐penten‐2‐ylamino)benzoates (2a–2c), 3‐(2‐HOC6H4CH=N)C6H4COOSnR3, and 3‐(CH3COCH=C(CH3)NH)C6H4COOSnR3 (R = Ph, a; Cy, b; Bu, c) have been synthesized by one‐pot reaction of 3‐aminobenzoic acid, salicylaldehyde (or 2,4‐pentanedione), and triorganotin hydroxide and characterized by elemental analysis, infrared, and nuclear magnetic resonance (1H, 13C, and 119Sn) spectra. The crystal structures of 1a, 1b, and 2a–2c have been determined by the single crystal X‐ray diffraction. Complexes 1a and 2a exhibit a 44‐membered macrocyclic tetramer and a polymeric zigzag chain, respectively, in which tin atoms show trans‐[C3SnO2] trigonal bipyramidal geometry with the axial positions being occupied by the carboxylate oxygen atom and the phenolic (or ketone) oxygen atom from another ligand. Complex 1b adopts a distorted tetrahedral geometry at tin, and there are two molecules differing in the relative orientation of the carboxylate toward the imino group. Compounds 2a⋅CH3OH, 2b⋅H2O, and 2c⋅H2O are five‐coordinated mononuclear adducts with one coordinated solvent molecule and display different supramolecular organizations in which there are the centrosymmetric R22(16), R42(22), and R64(34) macrocycle motifs formed by the O–H⋅⋅⋅O, N–H⋅⋅⋅O, and C–H⋅⋅⋅O hydrogen bonds. The fluorescence spectrum indicates that the complexes may be explored for potential blue luminescent materials. Compared to cisplatin, these compounds exhibit enhanced cytotoxic efficacy and can be considered as anticancer agents for further study.