Bis{2-[(E)-(5-tert-butyl-2-hy­droxy­phen­yl)diazen­yl]benzoato}dimethyl­tin(IV)

In the title diorganotin dicarboxyl­ate, [Sn(CH3)2(C17H17N2O3)2], the tin(IV) atom is six-coordinated by four O atoms derived from asymmetrically coordinating carboxyl­ate ligands, and two methyl-C atoms. The resulting C2O4 donor set defines a skew-trapezoidal bipyramid with the Sn—C bonds disposed over the weaker Sn—O bonds. Within each carboxyl­ate ligand, the hydroxyl-H atom forms bifurcated O—H⋯(O,N) hydrogen bonds with carboxyl­ate-O and azo-N atoms. The dihedral angles between the benzene rings in the two ligands are 10.44 (11) and 34.24 (11)°. In the crystal, centrosymmetric dimers are formed through pairs of Sn⋯O inter­actions [2.8802 (16) Å], and the dimers are linked into supra­molecular layers in the ac plane by C—H⋯π inter­actions

4-[(E)-(5-tert-Butyl-2-hydroxy­phen­yl)diazen­yl]benzoic acid benzene hemisolvate

The title benzene hemisolvate, C17H18N2O3·0.5C6H6, features an essentially planar (the r.m.s. deviation of the non-H atoms, excluding methyl-C, is 0.071 Å) diazo mol­ecule with an E conformation about the N=N bond, and a half-mol­ecule of benzene disposed about a centre of inversion. The dihedral angle formed between the benzene rings of the diazo mol­ecule is 7.69 (12)°. In the crystal, centrosymmetrically related dimers associate via the eight-membered carboxylic acid dimer synthon, {⋯HOC(=O)}2, and these are connected into a supra­molecular chain along the b axis via C—H⋯O contacts

Amino acetate functionalized Schiff base organotin(IV) complexes as anticancer drugs: synthesis, structural characterization, and in vitro cytotoxicity studies

Potassium 2-{[(2Z)-(3-hydroxy-1-methyl 2-butenylidene)]amino}-4-methyl-pentanoate (L1HK) and potassium 2-{[(E)-1-(2-hydroxyphenyl)alkylidene]amino}-4-methyl-pentanoates (L2HK-L3HK) underwent reactions with PhnSnCl4-n (n = 2 and 3) to give the amino acetate functionalized Schiff base organotin(IV) complexes [Ph3SnLH]n (1-3) and [Ph2SnL] (4), respectively. These complexes have been characterized by 1H, 13C, 119Sn NMR, IR spectroscopic techniques in combination with elemental analyses. The crystal structures of 1 and 3 were determined. The crystal structures reveal that the complexes exist as polymeric chains in which the L-bridged Sn-atoms adopt a trans-R3SnO2 trigonal bipyramidal configuration with the Ph groups in the equatorial positions and the axial locations occupied by a carboxylate oxygen atom from one carboxylate ligand and the alcoholic or phenolic oxygen atom of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic/phenolic proton moved to the nearby nitrogen atom. The solution structures were predicted by 119Sn NMR spectroscopy. When these organotin(IV) complexes were tested against A498, EVSA-T, H226, IGROV, M19 MEL, MCF7 and WIDR human tumor cell lines, the average ID50 values obtained were 55, 80 and 35 ng/ml for triphenyltin(IV) compounds 1-3, respectively. The most cytotoxic triphenyltin(IV) compound in the present report (3) with an average ID50 value of around 35 ng/ml is found to be morer cytotoxic for all the cell lines studied than doxorubicin, cisplatin, 5-fluorouracil and etoposide

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

Four new triphenyltin(IV) complexes containing [((E)-1-{2-hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene) amino]acetate ligands (L) have been synthesized with formulations of Ph3SnLH. They have been studied by multinuclear (1H, 13C, 119Sn) NMR, 119Sn Mössbauer and IR spectroscopy. A full characterization of one complex, Ph3SnL1H (1), was accomplished by single crystal X-ray crystallography, which revealed the compound to be a macrocyclic tetramer. In the tetramer, the five coordinate tin atoms have distorted trigonal bipyramidal geometries with the three phenyl groups occupying equatorial positions, while an oxygen atom of the carboxylate group of one L ligand and the oxide O-atom (formerly the hydroxy group) of a second L ligand in an apical positions. The carboxylate ligands bridge adjacent tin atoms and coordinate in the zwitterionic form with the phenolic proton moved to the nearby nitrogen atom. 119Sn NMR results indicate that the tetrameric structures of the complexes in the solid state, in which the tin atoms are five-coordinated, dissociate in solution to yield four coordinate monomeric species

Mono- and di-anionic coordination modes of arylazosalicylates in their bis(η5-cyclopentadienyl)titanium(IV) complexes: Syntheses and crystal structures

The bis(η5-cyclopentadienyl)titanium(IV) complexes of 5-[(E)-2-(aryl)-1-diazenyl]-2-hydroxybenzoic acids (H2LXASA) where the aryl group is an X-substituted phenyl ring such that X = CH, COEt, CMe, CF, CCl, CBr and N have been synthesised. Two types of titanium(IV) compounds viz. (i) [Ti(η5-C5H5)2(O2CC6H3(OH-2)(NNC6H4(H-4)-5))2] (3) and [Ti(η5-C5H5)2(O2CC6H3(OH-2)(NNC6H4(OC2H5-4)-5))2] (4), and (ii) [Ti(η5-C5H5)2(O2CC6H3(O-2)(NNC6H4(CH3-4)-5))] (5), [Ti(η5-C5H5)2(O2CC6H3(O-2)(NNC6H4(F-4)-5))] (6), [Ti(η5-C5H5)2(O2CC6H3(O-2)(NNC6H4(Cl-4)-5))] (7), [Ti(η5-C5H5)2(O2CC6H3(O-2)(NNC6H4(Br-4)-5))] (8) and [Ti(η5-C5H5)2(O2CC6H3(O-2)(NNC5H4(N-4)-5))] (9) were isolated and characterised by IR, 1H and 13C NMR spectroscopic techniques. The crystal and molecular structures of 3–9 have been determined by single crystal X-ray crystallography. Compounds 3 and 4 conform to the formula Cp2Ti(HLXASA-κO)2 with a monodentate carboxylate ligand while those of 5–9 conform to Cp2Ti(LXASA-κ2O1,O2) with the dianions chelating the titanium atoms via carboxylate-O and hydroxy-O atoms. The common feature of the molecular structures is the adoption of distorted tetrahedral geometries based (Cp)2O2 donor sets. HydroxylOH…O(carbonyl) bonding leads to supramolecular chains in the crystal of 4 but, these are absent in 3. Persistent CpCH…O(carbonyl) interactions, with the carbonyl atoms accepting two or three such interactions, lead to supramolecular chains with helical (5, 7 and 8) or linear (6 and 9) topologies; C–X…π interactions also play an important role in the packing of 6–8

3-[(2-Hydroxybenzyl)azaniumyl]propanoate monohydrate

The title compound, C10H13NO3·H2O, is a zwitterion hydrate with the zwitterion comprising a central ammonium group and a carboxyl­ate residue. In the zwitterion, the hy­droxy­benzene and carboxyl­ate groups are directed to the same side of the mol­ecule and each orientated to place an O atom in a position to form an intra­molecular ammonium-N-H...O hydrogen bond, each closing an S(6) loop. The three-dimensional architecture is stabilized by hy­droxy-O-H...O(carboxyl­ate), water-O-H...O(carboxyl­ate) and ammonium-N-H...O(water) hydrogen bonds

Synthesis and Structures of Two Triorganotin(IV) Polymers R3Sn{O2CC6H4[N=C(H)}{C(CH3)CH(CH3)-3-OH]-p}n (R = Me and Ph) Containing a 4-[(2Z)-(3-Hydroxy-1-methyl-2-butenylidene)amino] benzoic Acid Framework

Two new polymeric triorganotin(IV) complexes R3Sn{O2CC6H4[N=C(H)}{C(CH3)CH(CH3)-3-OH]-p}n ([Me3Sn(LH)]n: 1) and([Ph3Sn(LH)]n: 2) containing a 4-[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)amino]benzoate (LH) framework were prepared.Both compounds have been characterized by 1H, 13C, 119Sn NMR, IR and 119Sn Mossbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of complexes 1 and 2 reveal that they exist as polymeric zig-zag chains in which the LH-bridged Sn-atoms adopt a trans-R3SnO2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the alcoholic oxygen atom of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic proton moved to the nearby nitrogen atom

An ortho­rhom­bic polymorph of 5-[(4-methyl­phen­yl)diazen­yl]salicylaldehyde

The title compound, C14H12N2O2, is an ortho­rhom­bic polymorph of the previously reported monoclinic form [Bakir et al. (2005 ▶). Acta Cryst. E61, o1611–o1613]. The dihedral angle between the aromatic rings is 4.32 (13)°. The mol­ecular structures of the two polymorphs, including short intra­molecular O—H⋯O hydrogen bonds between the the hydr­oxy and keto groups, are quite similar but their crystal packings are distinct. Unlike the monoclinic form, in which centrosymmetrically related hydr­oxy and keto groups form {⋯H⋯O}2 synthons via weak O—H⋯O contacts, leading to dimeric aggregates, in the ortho­rhom­bic form, the hydrogen bonding between these groups leads to the formation of supra­molecular chains orientated along the a axis

Crystalline bis(η5-cyclopentadienyl)bis(benzoato/carboxylato)titanium(IV) precursordirected route to functional titanium dioxide nanomaterials

Five titanocene(IV) carboxylates of the general formula Cp2Ti(O2CR)2 viz., [Ti(η5-C5H5)2(O2CC6H5-4-CH3)2] (1), [Ti(η5 -C5H5)2(O2CC4H3-2-O)2] (2), [Ti(η5-C5H5)2(O2CC4H3-3-O)2] (3), [Ti(η5-C5H5)2(O2CC(CH3)3)2] (4) and [Ti(η5-C5H5)2(O2C(CH)C(CH3)3)2] (5) have been synthesized. All the titanocene(IV) carboxylates have been characterized by IR, 1H and 13C NMR spectroscopic techniques, and the crystal and molecular structures of 1-5 have been determined by single crystal X-ray crystallography. The structures present similar features with monodentate carboxylate ligands and tetrahedral Ti centres, assuming the each Cp ring occupies one position only. The differences in the structures relate primarily to the relative orientations of the carboxylate ligands. In the molecular packing, non-conventional Cp-C–H …O(carbonyl) hydrogen bonds are observed in each case and lead to supramolecular chains in each of 1, 4 and 5. In 2, the 2-furyl-O atoms also participate in C–H …O interactions leading to a two-dimensional array. Finally, in 3, a two-dimensional array arises as a result of Cp-C–H …O(carbonyl) and 3-furyl-C–H …O(carbonyl) interactions. As representative example, compound 3 was used as starting material for the synthesis of TiO2 nanoparticles

Targeting Mitochondrial Cell Death Pathway to Overcome Drug Resistance with a Newly Developed Iron Chelate

Background: Multi drug resistance (MDR) or cross-resistance to multiple classes of chemotherapeutic agents is a major obstacle to successful application of chemotherapy and a basic problem in cancer biology. The multidrug resistance gene, MDR1, and its gene product P-glycoprotein (P-gp) are an important determinant of MDR. Therefore, there is an urgent need for development of novel compounds that are not substrates of P-glycoprotein and are effective against drug-resistant cancer. Methodology/Principal Findings: In this present study, we have synthesized a novel, redox active Fe (II) complex (chelate), iron N- (2-hydroxy acetophenone) glycinate (FeNG). The structure of the complex has been determined by spectroscopic means. To evaluate the cytotoxic effect of FeNG we used doxorubicin resistant and/or sensitive T lymphoblastic leukemia cells and show that FeNG kills both the cell types irrespective of their MDR phenotype. Moreover, FeNG induces apoptosis in doxorubicin resistance T lymphoblastic leukemia cell through mitochondrial pathway via generation reactive oxygen species (ROS). This is substantiated by the fact that the antioxidant N-acetyle-cysteine (NAC) could completely block ROS generation and, subsequently, abrogated FeNG induced apoptosis. Therefore, FeNG induces the doxorubicin resistant T lymphoblastic leukemia cells to undergo apoptosis and thus overcome MDR. Conclusion/Significance: Our study provides evidence that FeNG, a redox active metal chelate may be a promising ne