Adonis Michaelides

Synthesis, structural characterization and in vitro cytotoxicity of organotin(IV) derivatives of heterocyclic thioamides, 2-mercaptobenzothiazole, 5-chloro-2-mercaptobenzothiazole, 3-methyl-2-mercaptobenzothiazole and 2-mercaptonicotinic acid.

Five new organotin(IV) molecules with the heterocyclic thioamides; 2-mercaptobenzothiazole (Hmbzt), 5-chloro-2-mercaptobenzothiazole (Hcmbzt), 3-methyl-2-mercaptobenzothiazole (mmbzt) and 2-mercaptonicotinic acid (H(2)mna) of formulae [(n-C(4)H(9))(2)Sn(mbzt)(2)] (1), [(C(6)H(5))(2)Sn(mbzt)(2)] (2), [(CH(3))(2)Sn(cmbzt)(2)].1.7(H(2)O)] (3), [(n-C(4)H(9))(2)SnCl(2)(mmbzt)(2).(CH(2)Cl(2))] (4) and [[(C(6)H(5))(3)Sn](2)(mna).[(CH(3))(2)CO]] (5) have been synthesized and characterized by elemental analysis, 1H-, 13C-NMR, FT-IR and Mössbauer spectroscopic techniques. Crystal structures of molecules 1, 3 and 5 have been determined by X-ray diffraction at 173(1) K (1 and 5) and 293(2) K (3). Compound 1 C(22)H(26)N(2)S(4)Sn, is monoclinic, space group C2/c, a=44.018(2), b=8.8864(5), c=12.8633(7) A, beta=104.195(5) degrees, Z=8. Compound 3 is also monoclinic, space group P2(1)/c and a=17.128(2) A, b=17.919(2) A, c=7.3580(10) A, beta=98.290(10) degrees, Z=4. In both molecules 1 and 3, two carbon atoms from aryl groups, two sulfur and two nitrogen atoms from thione ligands form a distorted octahedral geometry around tin(IV) with trans-C(2), cis-N(2), cis-S(2) configurations. Compound 5 C(45)H(39)NO(3)SSn(2) is monoclinic, space group P2(1)/n, a=9.1148(2) A, b=29.2819(6), c=15.5556(4) A, beta=106.2851(9) degrees, Z=4. Complex 5 contains two [(C(6)H(5))(3)Sn(IV)] moieties linked by a double deprotonated 2-mercaptonicotinic acid (H(2)mna). Both tin(IV) ions are five coordinated. This complex is the an example of a pentacoordinated Ph(3)SnXY system with an axial-equatorial arrangement of the phenyl groups at Sn(1) atom. Compounds 1, 3 and 5 were tested for in vitro cytotoxicity against the cancer cell line of sarcoma cells (mesenchymal tissue) from the Wistar rat, polycyclic aromatic hydrocarbons (benzo[a]pyrene) carcinogenesis. Compound 5 exhibits strong cytotoxic activity, while complexes 1 and 3 show less cytotoxic activity.

Synthesis, study and structural characterization of a new water soluble hexanuclear silver(I) cluster with the 2-mercapto-nicotinic acid with possible antiviral activity

Abstract Silver(I) chloride reacts with 2-mercapto-nicotinic acid (H2mna, C6H5NO2S) in the presence of an excess of triethylamine in DMSO to form a hexanuclear, water soluble, cluster of formula {[Ag6(μ3-Hmna)4(μ3-mna)2]2−·[(Et3NH)+]2·(DMSO)2·(H2O)} (1). The complex 1 was characterized by elemental analyses, and FT-IR, UV–Vis and 1H NMR spectroscopy. Crystal structures of complex 1 and the ligand, 2-mecapto-nicotinic acid (2), have been determined by X-ray diffraction. Compound 1, C52H68Ag6N8O15S8, is monoclinic with a space group P21/c (No. 14) and a=11.7080(10), b=16.2920(10), c=18.3010(10) A, β=91.350(10)°, Z=4. The entire molecule is ionic and consists of a double anionic hexa-nuclear cluster and two protonated triethylamine counter cations while it is solvated by two DMSO and one water molecule. The 2-mercapto-nicotinic acid (2), C6H5NO2S, is orthorhombic (space group Pna21 (No. 33), a=8.3910(10), b=13.2720(10), c=5.892 A, Z=4). An extended inter-molecular hydrogen bonding via O⋯HN contacts (O(1)⋯H(5)[N(5)]=1.8998, O(1)⋯N(5)=2.8049 A) links the molecules forming a supramolecular two-dimensional network. Complex 1, was evaluated for anti-HIV-RT activity. It was found to inhibit the human immunodeficiency viral replication reverse transcriptase (HIV-RT) with calculated inhibiting concentration (IC50) 0.01275±0.00115 mg ml−1.

Assembly of a photoreactive coordination polymer containing rectangular grids

We describe the synthesis, crystal structure and solid state reactivity of cadmium fumarate dihydrate, which is made up of planar H-bonded metal-organic layers and undergoes, upon irradiation, a topochemical [2 + 2] cycloaddition reaction.

Palladium(II) complexes of 2-acylpyridines. The crystal structure of dibromo bis(phenyl-2-pyridyl ketone)palladium(II)

Abstract Reaction of Pd(II) with 2-pyridine-carboxaldehyde (PC), methyl 2-pyridyl ketone (MPK) and phenyl 2-pyridyl ketone (PPK) in methanolic solutions gave six new complexes which have been characterized by elemental analysis, conductivity measurements, and IR and UV-Vis spectroscopic techniques. The ligands PC and PPK behave as monodentate and exhibit nitrogen coordination while MPK exhibits N, O ligation through the ring nitrogen and carbonylic oxygen atom in the production of a five membered chelate ring. The crystal structure of the Pd(II) complex of PPK has been determined by single crystal X-ray diffraction methods. Crystal data are: monoclinic space group P21/n, a=8.707(3), b=14.394(3), c=8.967(3) A, β=93.45(2)°, Dcalc=1.871 g cm−3, V=1121.8 A3, RF=0.062; Rw=0.068, GOF=2.0. The complex molecule is the trans-isomer of a square planar structure and the central Pd(II) lies on a center of symmetry and is coordinated by two bromides and two pyridine ring nitrogen atoms.

Designed self-assembly of a reactive metal–organic framework with quasi α-Po topology

A 2D layered structure composed of Cd dimers, linked by fumarate anions to form a rectangular grid network, was pillared, via metal coordination, to afford a 3D photoreactive metal–organic framework.

THE CRYSTAL STRUCTURE OF DIBROMO (PHENYL-2-PYRIDYL DIMETHYLHYDRAZONE)PALLADIUM(II)

Abstract Nitrogen-containing heterocyclic compounds play an important role in several biological processes. Furthermore, their biological activity seems often to depend upon interaction with a metal ion. Interest in the study of hydrazones and their metal complexes has been growing because of their physiological activity, coordination capability and application in analytical chemistry.1,2 Many hydrazones and their metallic derivatives show very interesting biological activity, e.g., as antitumour or anticonvulsant agents, and behave as cytotoxic compounds toward tumour cells.3 During the past few years, in addition to platinum compounds, coordination compounds of palladium(II) and (IV) seem to be promising in cancer chemotherapy.4 Due to the biological activity of heterocyclic hydrazones and in continuing our systematic investigations of the platinum group metals with hydrazones and generally with heterocyclic nitrogen donor ligands,5–10 we report here the crystal structure of dibromo(phenyl-2-pyridyldime...

The Question of Electrophilic vs Nucleophilic Addition of Cyclic β-Dicarbonyl Phenyliodonium Ylides: Electrophilic Cycloaddition of Diphenylketene

The reaction of β-dicarbonyl phenyliodonium ylides with diphenylketene at room temperature affords mixtures of lactone and aurone derivatives. The initial electrophilic attack of the iodonium ylide on the C(β) position of the diphenylketene, followed by cyclization of the zwitterionic species, and subsequent ejection of iodobenzene, affords the lactone and aurone cycloadducts. Treatment of β-dicarbonyl iodonium ylides with acyl chlorides yields α-chloroenones with good to excellent yields.

Crystallization of an unstable molecular compound using a tailor-made additive

Abstract A tailor-made additive has been used to control the crystallization process in supersaturated solutions of [Pd(HL)2]X2 (HL=2-acetylpyridine thiosemicarbazone and X=Br, Cl), a potential DNA inhibitor.

A Self-assembling Trinuclear Molecular Complex of Nickel( II ) with Benzene-1,3,5-tricarboxylic Acid

[Ni 3 (trim) 2 (H 2 O) 14 ]·4H 2 O (trim=trimesate trianion), a self-complementary molecule organised in tapes using aqua ligands as hydrogen bond donors and carboxylate groups as hydrogen bond acceptors, is synthesised and the structure confirmed by X-ray crystallography.

Habit modification of coordination compounds in the presence of additives; a study of the system Ni(β-ala)2 . 2H2O-glycine

For the understanding of the influence of organic complexing additives on crystal growth, we studied the habit modification of Ni(β-ala)2·2H2O crystals in the presence of glycine. We show that the mixed complex Ni(β-ala)(gly)·2H2O is formed on the crystal surface and causes disruption of one hydrogen bond in the 1[⦶1]0 direction, accounting for the observed habit modification.