Bis{4-methylbenzyl 2-[4-(propan-2-yl)benzylidene]hydrazinecarbodithioato-κ2N2,S}nickel(II): crystal structure and Hirshfeld surface analysis

The complete molecule of the title hydrazine carbodithioate complex, [Ni(C19H21N2S2)2], is generated by the application of a centre of inversion. The NiII atom is N,S-chelated by two hydrazinecarbodithioate ligands, which provide a trans-N2S2 donor set that defines a distorted square-planar geometry. The conformation of the five-membered chelate ring is an envelope with the NiII atom being the flap atom. In the crystal, p-tolyl-C—H...π(benzene-iPr), iPr-C—H...π(p-tolyl) and π–π interactions [between p-tolyl rings with inter-centroid distance = 3.8051 (12) Å] help to consolidate the three-dimensional architecture. The analysis of the Hirshfeld surface confirms the importance of H-atom contacts in establishing the packing

Synthesis, characterisation and structure determination of 3-[(1Z)-{2-[bis({[(2-methylphenyl)methyl]sulfanyl})methylidene]hydrazin-1-ylidene}methyl]benzene-1,2-diol

A light-yellow crystalline product (1), which was isolated after one week from the filtrate of the reaction between S-2-methylbenzyldithiocarbazate and 2,3-dihydroxybenzaldehyde, was characterised by single crystal X-ray diffraction, FTIR and NMR spectroscopic analyses. The experimental molecular structure of 1 has been established by X-ray crystallography and showed, to a first approximation, a planar C2N2S2 + dihydroxyphenyl region that has an almost orthogonal relationship to the rings of the pendant S-bound benzyl groups. This structure has been verified via density functional theory calculations using the B3LYP/6311G(d,p) level of theory. The molecular packing featured linear supramolecular chains along the b-axis sustained by tolyl-C–H…N(imine) and tolyl-C–H…π(tolyl) interactions; the importance of these contacts is indicated by a Hirshfeld surface analysis

Di-n-butyl[N′-(3-methoxy-2-oxidobenzylidene)-N-phenylcarbamohydrazonothioato]tin(IV): crystal structure, Hirshfeld surface analysis and computational study

The title diorganotin Schiff base derivative, [Sn(C4H9)2(C15H13N3O2S)], features a penta-coordinated tin centre defined by the N,O,S-donor atoms of the dianionic Schiff base ligand and two methylene-C atoms of the n-butyl substituents. The resultant C2NOS donor set defines a geometry intermediate between trigonal–bipyramidal and square-pyramidal. In the crystal, amine-N—HO(methoxy) hydrogen bonding is found in a helical, supramolecular chain propagating along the b-axis direction. The chains are assembled into a layer parallel to (101) with methylene-C—H(phenyl) interactions prominent; layers stack without directional interactions between them. The analysis of the calculated Hirshfeld surface showed the presence of weak methylene-C—H(phenyl) interactions and short HH contacts in the inter-layer region. Consistent with the nature of the identified contacts, the stabilization of the crystal is dominated by the dispersion energy term

o-Vanillin derived Schiff Bases and their Organotin(IV) Compounds: Synthesis, structural characterisation, in-Silico studies and cytotoxicity

Six new organotin(IV) compounds of Schiff bases derived from S-R-dithiocarbazate [R = benzyl (B), 2- or 4-methylbenzyl (2M and 4M, respectively)] condensed with 2-hydroxy-3- methoxybenzaldehyde (oVa) were synthesised and characterised by elemental analysis, various spectroscopic techniques including infrared, UV-vis, multinuclear (1H, 13C, 119Sn) NMR and mass spectrometry, and single crystal X-ray diffraction. The organotin(IV) compounds were synthesised from the reaction of Ph2SnCl2 or Me2SnCl2 with the Schiff bases (S2MoVaH/S4MoVaH/SBoVaH) to form a total of six new organotin(IV) compounds that had a general formula of [R2Sn(L)] (where L = Schiff base; R = Ph or Me). The molecular geometries of Me2Sn(S2MoVa), Me2Sn(S4MoVa) and Me2Sn(SBoVa) were established by X-ray crystallography and verified using density functional theory calculations. Interestingly, each experimental structure contained two independent but chemically similar molecules in the crystallographic asymmetric unit. The coordination geometry for each molecule was defined by thiolate-sulphur, phenoxide-oxygen and imine-nitrogen atoms derived from a dinegative, tridentate dithiocarbazate ligand with the remaining positions occupied by the methyl-carbon atoms of the organo groups. In each case, the resulting five-coordinate C2NOS geometry was almost exactly intermediate between ideal trigonal-bipyramidal and squarepyramidal geometries. The cytotoxic activities of the Schiff bases and organotin(IV) compounds were investigated against EJ-28 and RT-112 (bladder), HT29 (colon), U87 and SJ-G2 (glioblastoma), MCF-7 (breast) A2780 (ovarian), H460 (lung), A431 (skin), DU145 (prostate), BE2-C (neuroblastoma) Int. J. Mol. Sci. 2019, 20, 854 2 of 34 and MIA (pancreatic) cancer cell lines and one normal breast cell line (MCF-10A). Diphenyltin(IV) compounds exhibited greater potency than either the Schiff bases or the respective dimethyltin(IV) compounds. Mechanistic studies on the action of these compounds against bladder cancer cells revealed that they induced the production of reactive oxygen species (ROS). The bladder cancer cells were apoptotic after 24 h post-treatment with the diphenyltin(IV) compounds. The interactions of the organotin(IV) compounds with calf thymus DNA (CT-DNA) were experimentally explored using UV-vis absorption spectroscopy. This study revealed that the organotin(IV) compounds have strong DNA binding affinity, verified via molecular docking simulations, which suggests that these organotin(IV) compounds interact with DNA via groove-binding interactions

Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: synthesis, X-ray crystallography and biological activity

Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines

Homoleptic tin(IV) compounds containing tridentate ONS dithiocarbazate Schiff bases: Synthesis, X-ray crystallography, DFT and cytotoxicity studies

Six new tin(IV) compounds derived from tridentate dinegatively charged ONS dithiocarbazate Schiff bases derived from 2-hydroxy-3-methoxybenzaldehyde (H2L1, H2L2 and H2L3) and 2,3-dihydroxybenzaldehyde (H2L4, H2L5 and H2L6) (where H2Ln = di-acids of Schiff base) are reported. The compounds were characterised by elemental analysis, FT-IR and multinuclear NMR (1H, 13C and 119Sn) spectroscopy. The crystal structures of tin(IV) [S-4-methybenzyl-β-N-(2-hydroxy-3-methoxybenzylmethylene)dithiocarbazate] (2) and tin(IV) [S-benzyl-β-N-(2-hydroxy-3-methoxy benzylmethylene)dithiocarbazate] (3) were determined by X-ray single crystal diffraction analysis. X-ray crystallography showed the molecular geometries in homoleptic 2 and 3 to be quite similar in which the dinegative tridentate ligand coordinated the tin atoms via thiolate-S, phenoxide-O and imine-N atoms. The coordination geometries are based on an octahedron with like-atoms mutually trans. The experimental findings were validated by density functional theory (DFT) calculations at the B3LYP/LanL2DZ/6-311G(d,p) level of theory. All the tin(IV) compounds, except the insoluble compound 2 were screened for their in vitro cytotoxicity against a panel ten of cancer cell lines and one normal breast cell line (MCF-10 A) by MTT assay. Interestingly, the cytotoxicity of five tin(IV) compounds against HT29, MCF7 and MIA was higher than the reference drug, cisplatin

Synthesis, structural characterisation and cytotoxicity study of tin(IV) compounds containing ONS Schiff bases

There is an urgent need for substantial investigation of non-platinum drugs with higher activity and improved selectivity to address the problem associated with the use of platinum-based compounds as therapeutic agents. In light of this, diphenyltin(IV), dimethyltin(IV) and tin(IV) compounds were synthesised from the Schiff bases of three series of dithiocarbazate (S-2-methylbenzyldithiocarbazate (S1), S-4-methylbenzyl dithiocarbazate (S2), S-benzyldithiocarbazate (S3)) and two series of thiosemicarbazides (4-methyl-3-thiosemicarbazide and 4-phenyl-3- thiosemicarbazide) with aldehydes, 2-hydroxy-3-methoxybenzaldehyde (oVa) or 2,3-dihydroxybenzaldehyde (catechol). The tin(IV) compounds formed were found to have a general formula of [R2Sn(ONS)] and [Sn(ONS)2] (where R = Me and Ph). The compounds were fully characterised by physico-chemical and spectroscopic methods. The spectroscopic results supported the coordination geometry in which the Schiff bases behaved as tridentate ONS donor ligands coordinating via azomethine nitrogen, thiolo sulphur and phenoxide oxygen atoms. A total of 11 crystal structures of the expected compounds were solved in this work. In order to verify the experimental data, the compounds were optimised using the density functional theory (DFT) method with the B3LYP hybrid exchange correlation functional with LanL2DZ pseudopotential on tin and 6-311G(d,p) Pople basis set for all other atoms. Diphenyltin(IV) compounds showed the most promising cytotoxicity with IC50 values ranging between 0.016 – 4.40 μM against a panel of twelve cancer cell lines (RT-112, EJ-28 (bladder), HT29 (colon), U87, SJ-G2, SMA (glioblastoma), MCF-7 (breast), A2780 (ovarian), H460 (lung), A431 (skin), Du145 (prostate), BE2-C (neuroblastoma) and MIA (pancreatic)). The three diphenyltin(IV) compounds of the oVa series were able to induce the production of Reactive Oxygen Species (ROS) and acted as a cell apoptosis inducer. Good binding interactions for all the diphenyltin(IV) compound series were observed and supported by molecular docking analysis, where hydrogen, electrostatic and hydrophobic binding interactions were observed. This highlights the important of two phenyl groups coordinated directly to the tin ion to enhance the cytotoxicity by strong π-π stacking interactions to biomacromolecules. Diphenyltin(IV) compounds could bring hope in the field of drug development against various diseases including cancers