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Cancer has become a leading cause of death worldwide, which is responsible for 7.6 million cancer deaths according to GLOBOCAN survey conducted in 2008. The exploration of cis -platin analogues (carboplatin, lobaplatin, nedaplatin, oxaliplatin) and their incorporation to the treatment of cancer patients has further led interest in exploring metal-based anticancer drugs. The current study describes the synthesis of two new tetra-coordinated mono- and tetranuclear organotin(IV) carboxylate complexes and their in vitro anticancer studies. Each one of the complexes ( 1–2 ) has been characterized by analytical (micro- and gravimetric analysis) and spectroscopic (FTIR, 1 H, 13 C, 119 Sn-NMR) techniques. Furthermore, molecular structures of 1 and 2 were elucidated using X-ray crystallography. The characterization data showed that the coordination took place via oxygen atoms from the carboxylate anions to generate 1 as an organodistannoxane dimer and 2 as a mononuclear complex. Exceptionally, the NMR spectroscopic and X-ray crystallographic study showed that acetone molecules also took part in crystallizing 2 . Both complexes were tested against three cancerous (colon cancer HCT 116, breast cancer MCF 7, leukemia K562) and one non-cancerous (3T3-L1) cell lines. Both complexes showed same IC 50 value (0.2 μM) against HCT 116, whereas for the other two cancer cell lines (MCF 7 and K562) and a normal cell line (3T3-L 1 ), 2 showed results better than 1 . Importantly, the complexes showed exceptional activity against MCF 7 and K562 cell lines and the IC 50 values were calculated in nanomoles (MCF 7, IC 50s = 86.5 and 53.4 nM; K 562, IC 50s = 22.9 and 49.6 nM for 1 and 2 , respectively). Both, 1 and 2 , showed IC 50 values many times better than the standard drugs (5-FU, Tamoxifen, betulinic acid and cis -platin) used. Compared to cancerous cell lines, the complexes showed mild toxicity against normal cells (3T3-L1). Overall, two remained relatively effective.

New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (k(b)=5.03-33.00×10(5) M(-1)) for L1-L3 and L5 and (6.14-9.47×10(4) M(-1)) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency.

Six new platinum(II) complexes of a thiosemicarbazone Schiff base with isatin moiety [PtL1 to Pt(L6)2] were synthesized by the reaction of platinum(II) with the following: (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide [L1H], (Z)-2-(5-methyl-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide [L2H], (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide [L3H], (Z)-N-methyl-2-(5-nitro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide [L4H], (Z)-N-methyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide [L5H], and (Z)-N-ethyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide [L6H]. The structures of these complexes were characterized by elemental analysis, IR, UV–Vis, 1H NMR, and mass spectrometry analyses. The structure of Pt(L6)2 was further characterized by single-crystal XRD. The interaction of these complexes with calf thymus (CT) DNA exhibited a high intrinsic binding constant (Kb = 3.5 × 104 to 3.29 × 106 M−1), which reflected the intercalative activity of these complexes toward CT DNA. This result was also confirmed by viscosity data. Data obtained from the in vitro anti-proliferative study clearly established the anticancer potency of PtL1, PtL2, PtL3, PtL5, and Pt(L6)2 against the human colorectal carcinoma cell line HCT 116.

Six new Cu(II) complexes of thiosemicarbazone Schiff base with isatin moiety were synthesized through the reaction of Cu(II) with (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (CuL1), (Z)-2-(5-methyl-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (CuL2), (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (CuL3), (Z)-N-methyl-2-(5-nitro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (CuL4), (Z)-N-methyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (CuL5), and (Z)-N-ethyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (CuL6). The structures of the Schiff bases and their copper complexes were characterized based on the elemental analysis, and on the infrared, UV–Vis, 1H and 13C NMR and ESI-mass spectral data. The structures of the CuL2 and CuL3 complexes were further characterized by single-crystal X-ray diffraction. The interaction of these complexes with calf thymus (CT)-DNA exhibited high intrinsic binding constant (Kb = 1.6 × 105–14.6 × 105 M−1), which reflected intercalative activity of these complexes toward CT-DNA. This result was also confirmed by the viscosity data. Electrophoresis studies revealed that the CuL1 and CuL2 complexes were able to cleave the DNA via oxidative pathway, whereas CuL3, CuL4, CuL5, and CuL6 induced DNA cleavage via oxidative and hydrolytic pathways. The in vitro anti-proliferative study establishes the anticancer potency of these compounds against the human colorectal carcinoma cell line.

In the title compound, C10H9FN4OS, which is approximately planar with a maximum deviation of 0.0881 (10) Å from the mean plane of the non-H atoms, an intramolecular N—H...O hydrogen bond generates anS(6) ring. In the crystal, molecules are linkedviaN—H...O hydrogen bonds, forming a helical chain along theaaxis. The chains are linked by N—H...S, C—H...S and C—H...F hydrogen bonds and C—H... π interactions into a three-dimensional network.

A series of Zn(II) ferrocenylthiosemicarbazones complexes derived from thiosemicarbazide and 4-methyl-, 4-ethyl-, and 4-phenyl-3-thiosemicarbazide were evaluated for their DNA binding propensity and chemical nuclease activity. The equilibrium binding constants, K b, of the complexes for binding with calf thymus DNA (CT DNA) were in the range of 0.68 × 103 to 2.8 × 104 M−1. The complexes do not intercalate into the nucleobases of CT DNA, as evident from viscosity measurements. They exhibit efficient nuclease activity in the absence of an activating agent and cleave supercoiled DNA into nicked and linear circular forms of DNA at very low concentrations.

Lycopene extraction was carried out via the ultrasonic assisted extraction (UAE) with response surface methodology (RSM). Sonication enhanced the efficiency of relative lycopene yield (enhancement of 26% extraction yield of lycopene in 6 replications at 40.0 min, 40.0 °C and 70.0% v/w in the presence of ultrasound), lowered the extraction temperature and shortened the total extraction time. The extraction was applied with the addition of oxygen-free nitrogen flow and change of water route during water bath sonication. The highest relative yield of lycopene obtained was 100% at 45.0 °C with total extraction time of 50.0 min (30:10:10) and ratio of solvent to freeze-dried tomato sample (v/w) of 80.0:1. Optimisation of the lycopene extraction had been performed, giving the average relative lycopene yield of 99% at 45.6 min, 47.6 °C and ratio of solvent to freeze-dried tomato sample (v/w) of 74.4:1. From the optimised model, the average yield of all-trans lycopene obtained was 5.11 ± 0.27 mg/g dry weight. The all-trans lycopene obtained from the high-performance liquid chromatography (HPLC) chromatograms was 96.81 ± 0.81% with 3.19 ± 0.81% of cis-lycopenes. The purity of total-lycopene obtained was 98.27 ± 0.52% with β-carotene constituted 1.73 ± 0.52% of the extract. The current improved, UAE of lycopene from tomatoes with the aid of RSM also enhanced the extraction yield of trans-lycopene by 75.93% compared to optimised conventional method of extraction. Hence, the current, improved UAE of lycopene promotes the extraction yield of lycopene and at the same time, minimises the degradation and isomerisation of lycopene.

Problem statement: Tremendous studies have been carried out on organotin(IV) complexes derivatives of carboxylate anions. However, the synthesis and characterization as well as the in vitro antibacterial screening activity of organotin(IV) carboxylate derived of 2-amino-5-nitrobenzoic acid have not been carried out. Approach: Organotin(IV) carboxylate complexes derivative of 2-amino-5-nitrobenzoic acid, 2-NH2-5-NO2-C6H3COOH have been successfully synthesized. The acid and complexes obtained were characterized quantitatively using C, H, N and Sn elemental analysis as well as spectroscopic methods such as infrared (FTIR) and nuclear magnetic resonance (1H, 13C, 1H-13C HMQC and 119Sn NMR). Moreover, the complexes obtained were screened for their in vitro antibacterial screening activity. Results: Monomeric R2Sn (2-NH2-5-NO2-C6H3COO)2 (R = methyl 1, butyl 2) and dimeric {[(Bu2Sn(2-NH2-5-NO2-C6H3COO)]2O}2 3 as well as Ph3Sn(2-NH2-5-NO2-C6H3COO) 4 are obtained in solid state. Results of the infrared spectroscopy on the acid and complexes showed that the coordination took place via oxygen atoms from the carboxylate anions. Based on the 119Sn NMR solution study, the tin atom of both complexes 1 and 2 exhibit six-coordination respectively and complex 3 exhibits five- and six-coordination whereas the tin atom of complex 4 exhibits five-coordination. Conclusion: Pure complexes derived of 2-amino-5-nitrobenzoic acid have been successfully obtained. Triphenyltin(IV) are found to possess better in vitro antibacterial screening activity on two gram-positive bacterial compared to the parent acid.

Problem statement: Many studies have been carried out on organotin(IV) complexes derivative of carboxylate anions. However, the synthesis and characterization as well as the cytotoxic assay of organotin(IV) carboxylate derived of 3-(dimethylamino)benzoic acid have not been studied. Approach: Organotin(IV) carboxylate complexes derivative of 3-(dimethylamino)benzoic acid, 3-[N(CH3)2]C6H4COOH have been successfully synthesized. Two types of diorganotin(IV) complexes, [{3-[N(CH3)2]C6H4COO(R)2Sn}2O]2 dimer (R = methyl 1, butyl 3) and {3-[N(CH3)2]C6H4COO}2(C4H9)2Sn, 2 (monomer) as well as 3-[N(CH3)2]C6H4COO(C6H5)3Sn, 4 were successfully synthesized and obtained in solid state. The acid and complexes 1-4 obtained were characterized quantitatively using C, H, N and Sn elemental analysis as well as spectroscopic methods such as infrared (FTIR) and nuclear magnetic resonance (1H, 13C, 1H-13C HMQC and 119Sn NMR). In addition, complexes 1-4 obtained were screened for their cytotoxicity activity against HepG2 cells line. Results: Infrared spectroscopy showed that the coordination took place via oxygen atoms from the carboxylate anions. This indicated that the carboxylate anion acts as monodentate ligand in complexes 2 and 4. However, for distannoxane dimer (complexes 1 and 3), the carboxylate anions are found to exhibit monodentate and bidentate manner. In 119Sn NMR solution study, the tin atoms of complexes 1-3 were five-coordinated and four-coordinated in complex 4. From the 119Sn NMR, the tin atom of complex 2 was five-coordinated, this might be upon dilution, the crystal lattice were broken up resulting the carboxylate anions assembly self-arrangement. Hence, one of the carboxylate anions was located close to the tin atoms and exhibited bidentate chelation while the other carboxylate anion exhibited monodentate chelation in complex 2. Conclusion: Pure complexes 1-4 have been successfully obtained and complex 4 possessed promising biological screening activity compared to the parent acid and complexes 1-3.

Three water soluble dicopper(II) complexes, tetrakis(μ-4-chloro-2-nitrobenzoato-κ2O,O′) bis[aquacopper(II)] (1), tetrakis(μ-2-chloro-6-fluorobenzoato-κ2O,O′)bis[aquacopper(II)] (2) and tetrakis(μ-2-chlorobenzoato-κ2O,O′)bis[aquacopper(II)] (3), have been synthesized. Complex 1 crystallizes in monoclinic system, space group C2/c with a = 28.813(3), b = 7.2368(6), c = 17.0053(14) A, β = 105.395° and Z = 4, while 2 crystallizes in triclinic system, space group P 1 ¯ with a = 7.5638(2), b = 13.0494(4), c = 16.7079(5) A, α = 106.003°, β = 90.388°, γ = 91.855° and Z = 2. In addition, all the complexes have been characterized by their elemental analysis, FT-IR, UV–Vis spectroscopy and cyclic voltammetry. All complexes have been found to be redox active displaying two quasi-reversible redox couples corresponding to CuIICuII to CuIICuI and CuIICuI to CuICuI redox processes, respectively. The results from the gel electrophoresis experiment of 1–3 on pBR322 DNA, have demonstrated the occurrence of oxidative cleavage in the presence of hydrogen peroxide. The hydroxyl radical has been found to be the reactive oxygen species that is responsible for the cleavage reaction. In the antiproliferation tests against MCF-7, DU 145, HeLa and HepG2 cancer cell lines, all complexes show significant preference against HepG2 cell lines. All complexes also show significant preference against HepG2 cancer cells line over Chang human normal liver cells which means 1–3 are more potent against cancer cells than normal cells. In antibacterial tests against nine pathogenic bacterial species, all complexes show a very selective trend whereby they exhibit antibacterial activity against the Gram negative bacteria Enterobacter aerogenes.

The Mannich aminomethylation of bis( l -alaninato)copper(II), Cu( l -ala)2, with formaldehyde and acetamide yields the bis[N-(N′-methylacetamido)- l -alaninato]copper(II) (1) and bis[N,N-di-(N′-methylacetamido)- l -alaninato]copper(II) (2) complexes. The crystal structure of 2 shows the amide N–H of the uncoordinated N-methylacetamido substituents and that of the coordinated N-methylacetamido substituents forming intra- and inter-molecular hydrogen bonding. Both complexes have been characterized by elemental analysis, UV–Vis spectroscopy, magnetic susceptibility measurements and EI mass spectroscopy. A gel electrophoresis experiment on the soluble complex 1 in Tris–NaCl buffer at pH 8.3, from which 2 is formed, shows oxidative cleavage of DNA by 1 in the presence of hydrogen peroxide. The cleavage efficiency of 1 is greater than that of its precursor, Cu( l -ala)2.

The crystal structure of a centrosymmetric dinuclear nickel(II) complex, formed from the reaction of bis(L-alaninato)nickel(II) with formaldehyde and methylamine, shows two bridging 2,4,8,10-tetramethyl-5-oxido-5′-carboxylato-2λ5,4,8,10-tetraazaspiro[5.5]undec-2-en(234-del)-ylium ligands, L, and two formato ligands; each nickel atom exists in a trans-N2O4 octahedral geometry with an average (μ-O)–Ni distance of 2.033(1) A and Ni···Nii distance of 2.894(1) A. Formation of L implicates an unprecedented deamination step involving activation of both the α-carbon and the α-methyl hydrogen atoms of the L-alaninato moiety.

In its crystal structure, mer-tris(β-alaninato)cobalt(III), mer-[Co(β-ala)3], assumes a half-chair conformation. The complex has been additionally characterized by UV–Vis spectroscopy on its buffered solutions, electrospray ionization-mass spectroscopy (ESI-MS) and cyclic voltammetry. Its larger λmax value (visible region) compared to cobalt(III) complexes of α-amino acids suggests that β-alaninate is a weaker field ligand. Compared to CoIII hexamine complexes with six nitrogen-ligating atoms, mer-[Co(β-ala)3], with a N3O3 coordination sphere, is more easily reduced. The complex alone does not cleave DNA but can do so in the presence of ascorbic acid in TBE buffer pH 8.3. DNA cleavage can be attributed to ascorbate free radicals generated by one-electron transfer from ascorbate ions to mer-[Co(β-ala)3]. This represents the first report of DNA cleavage by a cobalt chelated amino acid complex.

The synthesized cobalt(II) and nickel(II) complexes {[M(hmt)2(H2O)4][M(H2O)6]}(SO4)2·6H2O [M = Co(II) (1) and Ni(II) (2), hmt = hexamethylenetetraamine] share the same general formula and chemical name {[bis(hexamethylenetetraamine)tetraaquametal(II)][hexaaquametal(II)]} disulfate hexahydrate. Complexes 1 and 2 have been characterized by elemental analysis, infrared spectroscopy, thermal analysis and magnetic moment determination. Each complex has two different cationic complexes co-crystallizing with the sulfate anions. The crystal structure of 1has been determined. Both complex cations in 1 have distorted octahedral geometry and they are linked to the sulfate anions through the coordinated and lattice water molecules. Each sulfate anion is hydrogen bonded to ten water molecules; two of its oxygen atoms have two hydrogen bonds each while the other two oxygen atoms have three hydrogen bonds each. The three uncoordinated nitrogen atoms of hmt in each [Co(hmt)2(H2O)4]2+ cation are hydrogen bonded to water m...

The reactions of a series of bis(α-substituted glycinato)copper(II) complexes, Cu(aa) 2 , with formaldehyde and acetamide have been carried out. For Cu(aa) 2 with an activating α-alkyl or reactive α-hydroxyalkyl substituent, they undergo both aldol-type condensation and Mannich aminomethylation to yield complexes with an oxazolidine-ring and one methylacetamido pendant. The crystal structure of one of these complexes is reported. The Cu(aa) 2 with a non-activating α-alkyl substituent is diacetamidomethylated. A proposed mechanism to account for the above differences and an analysis of thermal decomposition data of the two types of complexes are further described.

The (N,N'-ethylenediglycinato)metal(II) complexes, M(edg) (M = Cu, Zn, Ni, Co) undergo N-hydroxymethylation with formaldehyde in the pH range similar to3.5-9.5 to yield the respective [N,N'-ethylenedi(N-hydroxymethyl-glycinato)]metal(II), ML x H2O (L = N,N'-ethylenedi(N-hydroxymethylglycinate); x = 4, 4.5). The crystal and molecular structures of the Ni(edg) 3H(2)O and ML 4H(2)O (M = Ni, Cu, Co) complexes have been determined; all the complexes have distorted octahedral geometries and their tetradentate ligands have oc-cis configuration. Analysis of these structures also shows that the N-hydroxymethylated ligands are stereospecifically coordinated. However, M(edg) do not undergo Mannich ammomethylation with formaldehyde and ammonia. In the reactions studied, the alpha-carbon of M(edg) is unaffected by formaldehyde attack. No further condensation of the N-hydroxymethyl substituents and their potential reactivity are also explained. (C) 2002 Elsevier Science B.V. All rights reserved.

In the reactions of bis(α-amino acidato)copper(II) with formaldehyde and benzamide, competing processes occur and the preferred pathway depends on the nature and number of the α-carbon substituents of the chelated amino acid, and the pH of the reaction medium. Aldol-type condensation yields complexes with oxazolidine ring(s) while Mannich aminomethylation results in the formation of complexes with N-methylbenzamido pendant arm(s). The crystal structure determination of bis(3-methylbenzamido-5-methyloxazolidine-4-carboxylato)copper(II) dihydrate establishes its formation from a combination of both processes, in which aldol condensation occurs first. The chemistry of these reactions is rationalized with a proposed reaction scheme. The synthesized compounds are characterized by infrared spectroscopy and microanalysis.

Reaction of di- n -butyltin oxide with 3,5-dichloro-4-hydroxybenzoic acid yields the title compound which crystallizes as the usual dicarboxylatotetraorganodistannoxane dimer. A crystal structure determination of the compound reveals the presence of a centrosymmetric planar Sn2O2 unit connected to exocyclic Sn atom via two bidentate bridging carboxylate ligands. The remaining two carboxylate ligands are coordinated to the exocyclic Sn atom in the monodentate mode.

Six novel palladium(II) complexes of a thiosemicarbazone Schiff base with isatin moiety (PdL1 to PdL6) were synthesized by the reaction of palladium(II) with the following: (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L1H), (Z)-2-(5-methyl-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L2H), (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L3H), (Z)-N-methyl-2-(5-nitro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L4H), (Z)-N-methyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L5H) and (Z)-N-ethyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L6H). The structures of these complexes were characterized using elemental analysis and infrared, UV–visible, 1H NMR and mass spectroscopies. The structure of PdL5 was further characterized using single-crystal X-ray diffraction. The interaction of these complexes with calf thymus DNA was characterized with a high intrinsic binding constant (Kb = 5.78 × 104 to 1.79 × 106 M−1), which reflected the intercalative activity of these complexes towards calf thymus DNA. This result was also confirmed from viscosity data. Electrophoresis studies revealed that complexes PdL1 to PdL6 could cleave DNA via an oxidative pathway in the presence of an external agent. Data obtained from an in vitro anti-proliferative study clearly established the anticancer potency of these compounds against the human colorectal carcinoma cell line HCT 116.

The reaction of 6-methylpyridine-2-carboxaldehyde phenylhydrazone (L) with Ph2SnCl2 has resulted in the formation of a complex salt [LH+]2[Ph2SnCl4]2-. X-ray diffraction studies on the salt reveal the structure of the [Ph2SnCl4] dianion to be centrosymmetric with the tin atom in a distorted octahedral trans-C2Cl4 environment; Sn-Cl(1) 2.598(2), Sn-Cl(2) 2.5875(7) and Sn-C(1) 2.146(3) A. Associated with the dianion are two [PhN(H)NC(H)C5H3(Me)N(H)] cations via two hydrogen bonding contacts apiece, unusually involving a true Sn-Cl bond.

A series of complexes derived from the reactions of tricyclohexyltin(IV) chloride, (C6H11)SnCl with various carboxylic acids have been synthesized and characterized respectively by using microanalytical, IR, 1 H, 13C and 119Sn NMR spectroscopic methods. (C6H11)3SnCl reacts with picolinic, nicotinic and 5-bromonicotinic acids leading to the formation of complexes with general formula (C6H11)3Sn(H2O) · L and (C6H11) 3SnCl · L (where L = deprotonated carboxylic acid) wherein the carboxylic acid coordinates to the Sn atom via one of the O atoms from the COOH group.

Thiophene-2-carboxaldehyde thiosemicarbazone, C4H3S–CHN–NH–C(S)NH2 (tctscH) obtained by the condensation reaction of thiophene-2-carboxaldehyde with thiosemicarbazide forms SnPh2Cl(tctsc), 1 and SnCl2(tctsc)2, 2 with SnPh2Cl2 and SnPhCl3 in 1:1 and 1:2 tin:ligand molar ratios, respectively. The crystal structure determination shows that in both 1 and 2, tctscH is deprotonated and functions as an anionic bidentate ligand, co-ordinating to the tin atom through its azomethine-N and thiol-S atoms. The geometry about the tin atom for complex 1 is distorted trigonal bipyramidal whereas for complex 2 is distorted octahedral. Note that dephenylation occurs during the formation of complex 2. Fungitoxicity and cytotoxicity of the two tin complexes and tctscH have been evaluated and the biological activity is more remarkable in complex 1 in comparison to the other.

In the title compound, [CuCl2(C20H14N4)], the coordination around the Cu atom is approximately square-planar. The dihedral angle between the pyridine and triazine rings is 5.26 (5)°. The crystal structure is stabilized by C—H⋯Cl inter­actions.

The title complex, [Cu2(C7H3F2O2)4(H2O)2], has a centrosymmetric dinuclear structure in which two symmetry-related CuII centers are bridged by four carboxyl­ate groups of distinct 2,6-difluoro­benzoate ligands, the Cu⋯Cu separation being 2.6139 (2) A. Each CuII center is five-coordinated by four O atoms of carboxyl­ate groups in the basal plane and the O atom of a water mol­ecule in the apical position.

In the title compound, [Sn(C4H9)2(C7H3N2O6)2]·C7H8, the SnIV atom is in a distorted tetrahedral environment. The nitro groups are twisted slightly away from the planes of the attached benzene rings. The molecules are linked by intermolecular C—H...O interactions and short O...N contacts, forming sheet-like structures paralled to the ab plane, and are cross-linked by π–π interactions.

The molecule of the title compound, [Sn(C4H9)2(C9H10NO2)2], has twofold rotation symmetry. The geometry of the Sn atom is distorted tetrahedral. The dimethylamine substituent is twisted slightly from the benzene ring. The molecules are stabilized by weak intermolecular C—H...π interactions.

In the title compound, [Sn(C6H5)3(C7H5N2O4)], the nitro and amino groups are coplanar with the attached benzene ring. The mol­ecules are linked by inter­molecular N—H⋯O inter­actions, forming one-dimensional chains along [010]. In addition, the crystal structure is further stabilized by inter­molecular C—H⋯π and π–π inter­actions.

The folded mol­ecular conformation of the title compound, C30H24N2O2, is described by the dihedral angles between the benzimidazole ring system and the naphthalene ring systems of 68.2 (1) and 78.4 (1)°. The crystal structure reveals π–π and C—H⋯π inter­actions.

The Sn atom in the title compound, [Sn(C6H5)3(C11H14NO2)], shows tetra­hedral coordination. The asymmetric unit has two independent mol­ecules; the crystal structure is stabilized by C—H⋯O and C—H⋯π inter­actions.

A crystal structure determination of the title compound reveals that it has a one‐dimensional polymeric structure co‐crystallized with molecules of the crystallization solvent, toluene, in 1:1 ratio in the crystal lattice. Each of the Sn atoms exists in a distorted trigonal bipyramidal geometry with the axial positions occupied by the O atom of the carboxylate group and the N atom of the pyridyl ring of the neighbouring molecule. The axial N′[sbnd]Sn[sbnd]O connection makes an angle approaching linearity (175.5(1)°).

The asymmetric unit of the title compound, C14H12N2O2, contains four crystallographically independent mol­ecules. The crystal packing is stabilized by π–π, N—H⋯O and C—H⋯π inter­actions.

The title compound, C28H40N2O2·0.5CH3OH, crystallizes with two mol­ecules of 1-{2-[(2-hydr­oxy-1-naphth­yl)methyl­eneamino]phenyl­iminiometh­yl}-2-naphtholate and one methanol solvent mol­ecule in the asymmetric unit. All bond lengths and angles are normal. The crystal structure is stabilized by π–π, O—H⋯O and C—H⋯π inter­actions.

Cancer cases are alarmingly increasing worldwide, and newer chemotherapeutic agents are needed. Recent analogs of cisplatin (carboplatin, lobaplatin, nedaplatin and oxaliplatin) and their marketing as advanced chemotherapeutic drugs have furthered the interest in metal-based anti-cancer drugs. In the current study, two new polymeric organotin(IV) carboxylate complexes (1 and 2) have been synthesized and characterized. Spectroscopic studies showed that coordination took place via carboxylates. Furthermore, X-ray crystallographic study on 1 indicated that it possesses a monomeric structure and exists in polymeric formation due to additional Sn–N coordination, assigning seven coordinations to each metal ion. Both the complexes were tested against three cancerous (human colon cancer, HCT 116; breast cancer, MCF-7; and leukemia, K562) and one non-cancerous (3T3-L1) cell lines. Complex 1 showed exceptional cytotoxicity against cancerous cell lines (IC50 = 1.0 μM for HCT 116; 258.7 nM for MCF-7; and 46.7 nM K562) and remained comparatively non-toxic against normal cells (IC50 = 37.0 μM). This shows that both complexes have selective cytotoxicity against cancer cells.

Six new nickel(II) complexes of thiosemicarbazone Schiff base with isatin moiety [Ni(L1)2 to Ni(L6)2] were synthesized through reaction of Ni(II) with (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L1H), (Z)-2-(5-methyl-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L2H), (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L3H), (Z)-N-methyl-2-(5-nitro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L4H), (Z)-N-methyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L5H), and (Z)-N-ethyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L6H). The structures of the Ni complexes were characterized through elemental analysis, infrared, and mass spectral data. The structure of the NiL2 complex was further characterized through single-crystal X-ray diffraction. The interaction of these complexes with calf thymus (CT-DNA) exhibited high intrinsic binding constants (Kb = 1.4 × 105 M-1 to 2.4 × 106 M-1), which reflected their intercalative activity toward CT-DNA. This result was also confirmed by viscosity data. Electrophoresis studies revealed that these complexes could cleave the DNA through the oxidative pathway. This in vitro anti-proliferative study establishes the anticancer potency of these compounds against human colorectal carcinoma cell line.

The crystal structure determination of the title compound reveals that it appears to be entirely novel. It does not contain a stannoxane ring, but both Sn atoms are held together by hydroxide and acetate bridges, forming a six-membered ring. Both Sn atoms occupy distorted trigonal bipyramidal environments with one bidentate bridging trichloroacetate group and one monodentate trichloroacetate group in axial positions, whilst the butyl groups and the bridging OH group lie in the equatorial plane.

From the reactions of SnCl4 with organotin(IV) chlorides (RSnCl3, R2SnCl2 and R3SnCl, where R = Bu, Me and Ph) with N-(2-hydroxybenzaldehyde)-1-amino-2-phenyleneimine, N-(2-hydroxyl-1-naphthaldehyde)-1-amino-2-phenyleneimine, N,N′-bis(2-hydroxybenzaldehyde)-1,2-phenylenediimine and N,N′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine a series of complexes have been synthesized and characterized, respectively, by microanalytical, IR, and 1H NMR spectroscopic methods. The Ph2SnCl2 reacted with N-(2-hydroxy-1-naphthaldehyde)-1-amino-2-phenyleneimine giving Ph2Sn(NAPPDI) [where NAPPDI = deprotonated N,N′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine], wherein the former Schiff base exhibit a facile intramolecular CN bond cleavage and intermolecular CN bond formation.

The reaction between diphenyltin(IV) dichloride and thiosemicarbazide using acetone–ethanol as solvent resulted in the formation of bis(acetone thiosemicarbazone-S)dichlorodiphenyltin(IV), SnPh 2 Cl 2 (atsc) 2 . The crystal structure determination of the compound revealed it to be a monomeric six-co-ordinated organotin(IV) complex. Each of the two atsc functions as a monodentate ligand, co-ordinating to the tin atom through the sulfur atom and conferring a distorted-octahedral geometry upon the tin. The Sn–S bond length is 2.712(1) A. The antifungal activity of the complex, atsc and SnPh 2 Cl 2 against four plant pathogens has been evaluated. The complex displays marked fungitoxicity against these fungi and is more fungitoxic than free atsc and SnPh 2 Cl 2 . It has also shown significant cytotoxicity against human colon adenocarcinoma, breast adenocarcinoma, hepatocellular carcinoma and acute lymphoblastic leukaemia.

Reaction of di-n-butyltin oxide with 2-amino-5-chlorobenzoic acid in 1:2 stoichiometry yields the title compound which crystallizes as the six-coordinate diorganotin dicarboxylate monomer. The crystal structure of the compound reveals the tin atom situated on a crystallographic two-fold axis in a skew-trapezoidal bipyramid geometry. The trapezoidal plane is defined by two asymmetrically chelating carboxylate groups; Sn-O bonds are 2.123(4) and 2.484(5) Angstrom and the C-Sn-C angle is 141.7(6)degrees: The nitrogen atom of the amino group of the carboxylate ligand does not participate in any significant interactions with the tin atom.

A series of neutral complexes derived from the reactions of Sn(NCS) 4 , PhSn(NCS) 3 and R 2 Sn(NCS) 2 (R = Me and Ph) with [1-[(4-methylphenylimino)methyl]-2-phenol] have been synthesized. An X-ray crystal structural study of the diisothiocyanatodimethyltin(IV) derivative has been performed and all synthesized compounds were characterized by IR, 1 H and 13 C NMR spectroscopies. All the complexes exhibit octahedral geometry with tin-oxygen (Sn-O) coordination.