Synthesis,characterization and cytotoxic activity of diorganotin complexes with Schiff base derived from salicylaldehyde and l-tyrosine

Seven diorganotin complexes with the Schiff bases derived from salicylaldehyde and l-tyrosine, R₂Sn[2-O-5-XC₆H₃CH?=?NCH(CH₂C₆ H₄OH-4)COO] (X?=?H (1), Br (2); R?=?Me (a), Et (b), Bu (c), Cy (cyclohexyl) (d)), were synthesized and characterized by elemental analysis, IR, ¹H and ¹³C NMR spectra, and the single-crystal X-ray diffraction. In methanol, the racemization of chiral center of l-tyrosinate fragment occurred and the racemic products were obtained. X-ray analyses of 1c, 1d, and 2a–2c showed that the tin atoms of the complexes exhibit distorted trigonal-bipyramidal geometries. In 1c, 1d, and 2c, the intermolecular O–H???O hydrogen bonds connected the molecules into 1-D supramolecular chain or a R₂²(20) macrocyclic dimer, and 2a and 2b formed the 2-D supramolecular network by the intermolecular Sn???O and O–H???O interactions. Bioassay results indicated that 1a, 1c, and 1d had moderate antibacterial activity against Escherichia coli and 1c, 1d, and 2c belonged to the efficient cytostatic agents against two human tumor cell lines (A549 and HeLa) and the activity tends to follow the order Cy > Bu?>?Et?>?Me for the R group attached to tin.     

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

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.     

Synthesis,structural characterization and cytotoxic activity of diorganotin(IV) complexes of N‐(5‐halosalicylidene)‐α‐amino acid

Fourteen new diorganotin(IV) complexes of N‐(5‐halosalicylidene)‐α‐amino acid, R′₂Sn(5‐X‐2‐OC₆H₃CH?NCHRCOO) (where X = Cl, Br; R = H, Me, i‐Pr; R′ = n‐Bu, Ph, Cy), were synthesized by the reactions of diorganotin halides with potassium salt of N‐(5‐halosalicylidene)‐α‐amino acid and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. The crystal structures of Bu₂Sn(5‐Cl‐2‐OC₆H₃CH?NCH(i‐Pr)COO) and Ph₂Sn(5‐Br‐2‐OC₆H₃CH?NCH(i‐Pr)COO) were determined by X‐ray single‐crystal diffraction and showed that the tin atoms are in a distorted trigonal bipyramidal geometry and form five‐ and six‐membered chelate rings with the tridentate ligand. Bioassay results of a few compounds indicated that the compounds have strong cytotoxic activity against three human tumour cell lines, i.e. HeLa, CoLo205 and MCF‐7, and the activity decreased in the order Cy>n‐Bu>Ph for the R′ group bound to tin. Copyright © 2005 John Wiley & Sons, Ltd.     

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

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, characterization and structural studies of diorganotin(IV) complexes with Schiff base ligand salicylaldehyde isonicotinylhydrazone

Eight diorganotin(IV) complexes of salicylaldehyde isonicotinylhydrazone (H₂SalN) R₂Sn(SalN) R = t-Bu 1, Ph 2, PhCH₂3, o-ClC₆H₄CH₂4, p-ClC₆H₄CH₂5,m-ClC₆H₄CH₂6,o-FPhCH₂7, p-FC₆H₄CH₂8 were prepared. All complexes 1-8 have been characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR analyses. The crystal structures of H₂SalN and complex 1 were determined by X-ray crystallography diffraction analyses. Studies show that H₂SalN is a tridentate planar ligand. For complex 1, the tin atom lies in this plane and forms a five- and six-membered chelate ring with the tridentate ligand. A comparison of the IR spectra of the ligand with those of the corresponding complexes, reveals that the disappearance of the bands assigned to carbonyl unambiguously confirms that the ligand coordinate with the tin in the enol form.     

Synthesis,structural characterization and cytotoxic activity of diorganotin(IV) complexes of N‐(5‐halosalicylidene)tryptophane

Four new diorganotin(IV) complexes of N‐(5‐halosalicylidene)tryptophane, R₂Sn[5‐X‐2‐OC₆H₃CH?NCH(CH₂Ind)COO] [Ind = 3‐indolyl; R, X = Et, Cl ( 1 ); Et, Br( 2 ); n‐Bu, Cl ( 3 ); n‐Bu, Br ( 4 )], were synthesized and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. The crystal structures of complexes 1 – 3 were determined by X‐ray single crystal diffraction and showed that the tin atoms are in a distorted trigonal bipyramidal geometry and form five‐ and six‐membered chelate rings with the tridentate ligand. Intermolecular weak interactions in 1–3 link molecules, respectively, into a two‐dimensional array, a one‐dimensional infinite chain and a one‐dimensional double‐chain supramolecular structure. Bioassay results of the compounds indicated that the dibutyltin complexes 3 and 4 have potent in vitro cytotoxic activity against two human tumor cell lines, CoLo205 and Bcap37, while the diethyltin complexes 1 and 2 display weak cytotoxic activity. Copyright © 2008 John Wiley & Sons, Ltd.     

Mononuclear diorganotin(IV) complexes with arylhydroxamates: syntheses,structures and assessment of in vitro cytotoxicity

Two series of diorganotin(IV) complexes with dihalogenobenzohydroxamate ligands (substituents = 2,4‐Cl₂, 2,4‐F₂, 3,4‐F₂, 2,5‐F₂, 2,6‐F₂), formulated as [R₂Sn(HL)₂] ( a ), and the arylhydroxamato/arylcarboxylato mixed‐ligand complexes [R₂Sn(HL)(L′)] ( b ), were prepared and characterized by FT‐IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopies, elemental analyses and melting point measurements. X‐ray diffraction analysis was also carried out for the complex [Me₂Sn{3,4‐F₂C₆H₃C(O)NHO}₂], 1a . These compounds exhibit in vitro cytotoxic activities towards human leukemic promyelocites HL‐60, BGC‐823, BEL‐7402 and KB cell lines which, in some cases, are identical to, or even higher than, that of cisplatin. The type, position and number of the X substituents in the phenyl ring play a role in the cytotoxic activity, and complex 8a , with its 2,6‐difluorobenzohydroxamato ligand, is highly active against all tumor cells. A tentative structure–activity relationship is also described. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis and characterization of diorganotin(IV) complexes of Schiff bases with ONO‐type donors and crystal structure of [N‐(2‐hydroxy‐4‐nitrophenyl)‐3‐ethoxysalicylideneiminato]diphenyltin(IV)

A series of neutral complexes, namely, [N‐(2‐hydroxy‐4‐nitrophenyl)‐3‐hydroxysalicylideneiminato]‐ diphenyltin(IV) ( Ia ), [N‐(2‐hydroxy‐4‐nitrophenyl)‐3‐methoxysalicylideneiminato]diphenyltin(IV) ( IIa ) and [N‐(2‐hydroxy‐4‐nitrophenyl)‐3‐ethoxysalicylideneiminato]diphenyltin(IV) ( IIIa ) were prepared by the reaction of diphenyltin dichloride on the corresponding Schiff bases. The Schiff bases were the reaction products of 2‐hydroxy‐4‐nitroaniline and appropriate salicylaldehydes. All the compounds were characterized by elemental analysis, ¹H‐NMR, ¹³C‐NMR, IR and mass spectroscopy. Compound IIIa was also characterized by single crystal X‐ray diffraction and shows a C₂NO₂ coordination geometry nearly half‐way between a trigonal bipyramidal and square pyramidal arrangement. In the solid state, π? π interactions exist between the aniline fragments of neighbouring molecules. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis,structure and in vitro cytotoxicity testing of some 1,3,4‐oxadiazoline derivatives from 2‐hydroxy‐5‐iodobenzoic acid

The syntheses of nine new 5‐iodosalicylic acid‐based 1,3,4‐oxadiazoline derivatives starting from methyl salicylate are described. These compounds are 2‐[4‐acetyl‐5‐methyl‐5‐(3‐nitrophenyl)‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6a ), 2‐[4‐acetyl‐5‐methyl‐5‐(4‐nitrophenyl)‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6b ), 2‐(4‐acetyl‐5‐methyl‐5‐phenyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl)‐4‐iodophenyl acetate, C₁₉H₁₇IN₂O₄ ( 6c ), 2‐[4‐acetyl‐5‐(4‐fluorophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate, C₁₉H₁₆FIN₂O₄ ( 6d ), 2‐[4‐acetyl‐5‐(4‐chlorophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate, C₁₉H₁₆ClIN₂O₄ ( 6e ), 2‐[4‐acetyl‐5‐(3‐bromophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6f ), 2‐[4‐acetyl‐5‐(4‐bromophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6g ), 2‐[4‐acetyl‐5‐methyl‐5‐(4‐methylphenyl)‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6h ) and 2‐[5‐(4‐acetamidophenyl)‐4‐acetyl‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6i ). The compounds were characterized by mass, ¹H NMR and ¹³C NMR spectroscopies. Single‐crystal X‐ray diffraction studies were also carried out for 6c , 6d and 6e . Compounds 6c and 6d are isomorphous, with the 1,3,4‐oxadiazoline ring having an envelope conformation, where the disubstituted C atom is the flap. The packing is determined by C—H…O, C—H…π and I…π interactions. For 6e , the 1,3,4‐oxadiazoline ring is almost planar. In the packing, Cl…π interactions are observed, while the I atom is not involved in short interactions. Compounds 6d , 6e , 6f and 6h show good inhibiting abilities on the human cancer cell lines KB and Hep‐G2, with IC₅₀ values of 0.9–4.5 µM.     

Synthesis,characterization and binding studies of novel diorganotin(IV) complexes of sodium 2‐mercaptoethanesulfonate

Diorganotin(IV) complexes ( 1‐4) of MESNA (sodium 2‐mercaptoethanesulfonate HSCH₂CH₂SO₃Na) and a mixed ligand complex of dibutyltin(IV), 1,10‐phenanthroline and MESNA ( 5 ) were synthesized with thermal and microwave assisted methods. All the complexes were characterized thoroughly with the help of analytical and various spectroscopic techniques viz. FTIR, NMR (¹H, ¹³C, and ¹¹⁹Sn NMR) spectroscopy and ESI‐MS spectrometery. Various spectrophotometric studies were carried out to decipher the binding mode of MESNA and its diorganotin complexes 1 ‐ 5 with calf thymus DNA (CT DNA) and thus, to calculate the binding constant (K_b). Absorption spectrophotometric study confirmed the interaction is through partial intercalation of all the complexes including MESNA, inside the DNA helix and calculated binding constant (K_b) is in the order of 10³ M^‐1. A series of emission spectrophotometric experiments support the results obtained through the absorption spectrophotometric studies. Circular dichroic (CD) spectroscopic analysis and viscosity measurement of CT DNA further complemented the fact that the partial intercalation plays a major role in the interaction of the studied complexes with CT DNA. All the studies corroborated that complex 2 bound to CT DNA with maximum affinity followed by complex 5 among all the complexes. Involvement of hydroxyl radicals as an active species in the cleavage activity of pBR322 plasmid DNA is proved by carrying out agarose gel electrophoretic technique.     

Synthesis,spectral, structural characterization and biological activity of new palladium(II) complexes containing 3‐acetyl‐8‐methoxy‐2H‐chromen‐2‐one derived Schiff bases

Four different mononuclear palladium(II) complexes of 3‐acetyl‐8‐methoxycoumarin Schiff bases were synthesized and characterized by spectrochemical techniques. Further analysis through X‐ray crystallography confirmed the structures of the complexes. Their interactive ability with Calf Thymus DNA and protein (Bovine Serum Albumin and Human Serum Albumin) were investigated by means of absorption and emission methods. The intercalative mode of binding with DNA was supported by EB displacement studies and viscosity measurements. Configurational changes that occurred in the proteins have been analysed with the help of 3D fluorescence studies. The complexes were shown to have good antimicrobial activity against the tested bacterial and fungal pathogens. In addition, antiproliferative activity of the complexes was evaluated on A549 and MCF‐7 cell lines and the complexes were comparatively more active than the standard drug cisplatin. Among the compounds, complex 3 was the most effective against MCF‐7 (IC₅₀ value of 5.20 ± 0.15 μM) and A549 (5.09 ± 0.13 μM) compared with the other complexes 1 (6.48 ± 0.17 μM; 5.98 ± 0.09 μM), 2 (5.53 ± 0.12 μM; 5.85 ± 0.11 μM), 4 (6.73 ± 0.19 μM; 6.63 ± 0.16 μM) and cisplatin (16.79 ± 0.08 μM; 15.10 ± 0.05 μM) respectively. LDH and NO release assays confirmed the cytotoxic potential of the synthesized complexes.     

Synthesis,structural characterization and catalytic activities of dicopper(II) complexes derived from tridentate pyrazole‐based N2O ligands

A group of a diverse family of dinuclear copper(II) complexes derived from pyrazole‐containing tridentate N₂O ligands, 1,3‐bis(3,5‐dimethylpyrazol‐1‐yl)propan‐2‐ol (Hdmpzpo), 1,3‐bis(3‐phenyl‐5‐methyl pyrazol‐1‐yl)propan‐2‐ol (Hpmpzpo) and 1,3‐bis(3‐cumyl‐5‐methylpyrazol‐1‐yl)propan‐2‐ol (Hcmpzpo), were synthesized and characterized by elemental analysis, IR spectroscopy and three of them also by single‐crystal X‐ray diffraction. Three complexes, [Cu₂(pmpzpo)₂](NO₃)₂·2CH₃OH ( 3 ·2CH₃OH), [Cu₂(pmpzpo)₂](ClO₄)₂ ( 4 ) and [Cu₂(cmpzpo)₂](ClO₄)₂·2DMF ( 7 ·2DMF), each exhibits a dimeric structure with a inversion center being located between the two copper atoms. The metal ion is coordinated in a distorted square planar environment by two pyrazole nitrogen atoms and two bridging alkoxo oxygen atoms. Both complexes 1 ·CH₃OH·H₂O and 3 ·2CH₃OH were investigated in anaerobic conditions for the catalytic oxidation of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to the corresponding quinone (3,5‐DTBQ), for modeling the functional properties of catechol oxidase. Copyright © 2007 John Wiley & Sons, Ltd.     

New diorganotin(IV) complexes of Schiff base derived from 4‐amino‐3‐hydrazino‐5‐mercapto‐4H‐1,2,4‐triazole: Synthesis,structural characterization,density functional theory studies,atoms‐in‐molecules analysis and antifungal activity

New diorganotin(IV) complexes of a Schiff base (HL) having general formula R₂Sn(L)Cl (where L is the monoanion of HL and R = n‐Bu or Ph) have been synthesized and characterized using elemental analysis, infrared, NMR (¹H, ¹³C, ¹¹⁹Sn) and UV–visible spectroscopies and mass spectrometry. These investigations suggest that in these 1:1 monomeric derivatives the Schiff base ligand acts in a monoanionic bidentate manner coordinating through the O_phenolic and N_azomethine, with proposed distorted trigonal bipyramidal geometry around tin with O_phenolic and two organic groups in the equatorial plane and the N_azomethine and the third organic group in axial positions. The proposed structures have been validated by density functional theory (DFT)‐based quantum chemical calculations at the B3LYP/6‐31G(d,p)/Def2‐SVP (Sn) level of theory. The simulated UV–visible spectrum was obtained with the time‐dependent DFT method in the gas phase and in the solvent field with the integral equation formalism–polarizable continuum model. A comparative analysis of the experimental vibrational frequencies and simulated harmonic frequencies indicates a good correlation between them. An insight into the intramolecular bonding and interactions among bonds in organotin(IV) complexes of HL was obtained by means of natural bond orbital analysis. The topological and energetic properties of the electron density distribution for the tin–ligand interaction in R₂Sn(L)Cl have been theoretically calculated at the bonds around the central tin atom in terms of atoms‐in‐molecules theory. The R₂Sn(L)Cl complexes were screened for their in vitro antifungal activity against chosen fungal strains.     

Synthesis,properties and crystal structural characterization of diorganotin(IV) derivatives of 2‐mercapto‐6‐nitrobenzothiazole

The diorganotin(IV) dichlorides R₂SnCl₂ (R: Ph, PhCH₂ or n‐Bu) react with 2‐mercapto‐6‐nitrobenzothiazole (MNBT) in benzene to give [Ph₂SnCl(MNBT)] ( 1 ), [(PhCH₂)₂Sn(MNBT)₂] ( 2 ) and [(n‐Bu)₂Sn(MNBT)₂] ( 3 ). The three complexes have been characterized by elemental analysis and IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopies. X‐ray studies of the crystal structures of 1 , 2 and 3 show the following. The tin environment for complex 1 is distorted cis‐trigonal bipyramid with chlorine and nitrogen atoms in apical positions. The structure of complex 2 is a distorted octahedron with two benzyl groups in the axial sites. The geometry at the tin atom of complex 3 is that of an irregular octahedron. Interestingly, intra‐molecular non‐bonded Cl…S interactions and S…S interaction were recognized in the crystallographic structures of 1 and 3 respectively. As a result, complex 1 is a polymer and complex 3 is a dimer. Copyright © 2003 John Wiley & Sons, Ltd.     

Some divalent metal(II) complexes of salicylaldehyde‐derived Schiff bases: Synthesis,spectroscopic characterization,antimicrobial and in vitro anticancer studies

Mononuclear transition metal(II) complexes of the type M(L)₂?2H₂O (where M = Co, Ni, Cu, Zn) have been synthesized from uninegative Schiff base ligands (HL₁–HL₄) designed by condensation of 4‐fluorobenzylamine with 2‐hydroxy‐1‐naphthaldehyde/3,5‐dichlorosalicylaldehyde/3,5‐dibromosalicylaldehyde/3‐bromo‐5‐chlorosalicylaldehyde. The compounds were successfully characterized using spectroscopic and physiochemical methods together with elemental analysis. Spectroscopic elucidation indicates a monobasic bidentate nature of ligands coordinated via deprotonated phenolic oxygen and azomethine nitrogen atom which suggests an octahedral geometry around the central metal ions. The complexes and ligands were screened for their in vitro antimicrobial activity against bacterial and fungal strains, the zinc(II) complexes being more active against the tested microbial strains. Further, the metal complexes were found to be more active than the uncomplexed ligands due to chelation process and, moreover, the complexes were more active against fungal strains than bacterial strains. Cytotoxic activities of all compounds were evaluated towards human alveolar adenocarcinoma epithelial cell line (A549), human breast adenocarcinoma cell line (MCF7), human prostate cancer cell line (DU145) and one normal human lung cell line (MRC‐5) using MTT colorimetric assay with doxorubicin as a standard. The zinc complexes were most active against the cancer cell lines and also found to be less toxic against MRC‐5 normal cell line than standard doxorubicin.     

Synthesis,structure and cytotoxic activity of binuclear phenyltin(IV) complexes with N,N′‐bis(2‐hydroxybenzyl)‐1,2‐ethanebis(dithiocarbamate) ligand

Two new dinuclear phenyltin(IV) complexes derived from N,N′‐bis(2‐hydroxybenzyl)‐1,2‐ethanebis(dithiocarbamate) ligand, [2‐HOC₆H₄CH₂N(CS₂SnPh₃)CH₂]₂ ( 1 ) and [2‐HOC₆H₄CH₂N(CS₂SnClPh₂)CH₂]₂ ( 2 ) have been synthesized and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. The crystal structures of complexes 1 and 2 were determined by X‐ray single crystal diffraction and show that the dithiocarbamate ligand is coordinated to the tin atom in the anisobidentate manner and the tin atom is five‐coordinated. The coordination geometry of tin atom is best described as an intermediate between trigonal bipyramidal and square pyramidal with τ‐values of 0.63 and 0.53, respectively. Intermolecular hydrogen bonds (O H···S and O H···Cl) in 1 and 2 connect neighboring molecules into a one‐dimensional supramolecular chain with the centrosymmetric cyclic motifs. Complex 1 has potent in vitro cytotoxic activity against two human tumor cell lines, CoLo205 and Bcap37, while complex 2 displays weak cytotoxic activity. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis of 8‐hydroxyquinolium chloroacetate and synthesis of complexes derived from 8‐hydroxyquinoline,and characterization,density functional theory and biological studies

8‐Hydroxyquinolium chloroacetate ( L¹ ) was synthesized and characterized. The results suggest that L¹ loses ethyl chloroacetate ion on coordination at low pH (2–5) and consequently it behaves as 8‐hydoxyquinoline ( L² ). Cu²⁺, Co²⁺, Pt⁴⁺, Pd²⁺, Au³⁺, Ag⁺ and Nd³⁺ complexes derived from L² have been synthesized and characterized using spectral, magnetic and thermal measurements. L² acts as a neutral bidentate ligand in the case of Cu²⁺, Co²⁺, Pt⁴⁺, Pd²⁺ and Nd³⁺ complexes and as a mononegative bidentate ligand in the case of Au³⁺ and Ag⁺ complexes. Octahedral geometry is proposed for Cu²⁺, Co²⁺ (grey) and Pt⁴⁺ complexes and square‐planar for Co²⁺ (green), Pd²⁺ and Au³⁺ complexes. The bond lengths, bond angles, chemical reactivities, binding energies and dipole moments for all compounds were evaluated using density functional theory and molecular electrostatic potential for L¹ . Superoxide dismutase radical scavenger‐like activity and cytotoxic activity of the complexes towards HepG2 liver cancer cells has been screened. Cytotoxicity measurements show that Ag⁺ and Pd²⁺ complexes have the highest cytotoxic activity while L¹ , Cu²⁺, Co²⁺ (grey), Co²⁺ (green), Pt⁴⁺ and Nd³⁺ complexes have no cytotoxic activity. Copyright © 2015 John Wiley & Sons, Ltd.