Carlo Castellano

Synthesis, structural characterization, formation constants and in vitro cytotoxicity of phenanthroline and imidazolidine-2-thione copper(II) complexes

The synthesis, crystal structures, physicochemical properties and complex formation constants of [Cu(phen)(2)(L)](ClO(4))(2) complexes, where phen is 1,10-ortho-phenanthroline and L is a series of substituted imidazolidine-2-thione, have been studied. Single crystal X-ray diffraction revealed a distorted trigonal-bipyramidal geometry for all the molecules. The complex formation constants were determined in nonaqueous media by spectrophotometric measurements. Testing copper(II) complexes in mouse neuroblastoma N2a cells persistently infected with the 22L strain of the scrapie prion protein (22L-N2a) resulted in high cytotoxicity but no antiprion activity at nontoxic doses.

Dipeptide Nanotubes Containing Unnatural Fluorine-Substituted β2,3-Diarylamino Acid and l-Alanine as Candidates for Biomedical Applications

The synthesis and the structural characterization of dipeptides composed of unnatural fluorine-substituted β(2,3)-diarylamino acid and L-alanine are reported. Depending on the stereochemistry of the β amino acid, these dipeptides are able to self-assemble into proteolytic stable nanotubes. These architectures were able to enter the cell and locate in the cytoplasmic/perinuclear region and represent interesting candidates for biomedical applications.

Copper(II)-Catalyzed Alkoxyhalogenation of Alkynyl Ureas and Amides as a Route to Haloalkylidene-Substituted Heterocycles.

A highly effective synthesis of haloalkylidene-substituted heterocycles by copper(II)-catalyzed cyclization of alkynyl ureas and secondary amides has been developed. The reaction, which involves a catalytic amount of CuCl2 and a stoichiometric amount of N-halosuccinimide, occurs selectively through an alkoxyhalogenation process. Alternatively, alkoxychlorination and alkoxybromination reactions can be performed working solely with stoichiometric CuCl2 and CuBr2, respectively.

Novel copper(II) complexes as new promising antitumour agents. A crystal structure of [Cu(1,10-phenanthroline-5,6-dione)2(OH2)(OClO3)](ClO4).

The cytotoxic properties of copper(II) complexes with 1,10-phenanthroline (phen) can be modified by substitution in the phen backbone. For this purpose, Cu(II) complexes with phen, 1,10-phenanthrolin-5,6-dione (phendione) and 1,10-phenanthrolin-5,6-diol (phendiol) have been synthesised and characterised. The crystal structure of [Cu(phendione)2(OH2)(OClO3)](ClO4) is discussed. The complex formation equilibria between Cu(II) and phen or phendione were studied by potentiometric measurements at 25 and 37°C in 0.1 M ionic strength (NaCl). The antitumour activity of the compounds has been tested in vitro against a panel of tumour (DU-145, HEP-G2, SK-MES-1, CCRF-CEM, CCRF-SB) and normal (CRL-7065) human cell lines. The studied compounds generally present an antiproliferative effect greater than that of cisplatin. The phen and phendione ligands present a similar antiproliferative effect against all the tested cells. Phendiol presents an antiproliferative effect 1.3 to 18 times greater than that of phen or phendione for leukemic, lung, prostatic and fibroblast cells, while it presents less activity towards hepatic cells. Complexes with two ligands are more cytotoxic towards all the tested cell lines than complexes with one ligand and are generally more cytotoxic than the ligand alone. Complexes [Cu(phendiol)2(OH2)](ClO4)2 and [Cu(phendione)2(OH2)(OClO3)](ClO4) appear to be the most active compounds for the treatment of SK-MES-1 and HEP-G2 cells, respectively, being at least 18 times more cytotoxic than cisplatin. The studied Cu(II) complexes are characterised by a strong DNA affinity and were found to interact with DNA mainly by groove binding or electrostatic interactions. The complexes appear to act on cells with a mechanism different from that of cisplatin.

New minerals and nomenclature modifications approved in 2013 (IMA-CNMNC Newsletter 18)

P. A. WILLIAMS (Chairman, CNMNC), F. HATERT (Vice-Chairman, CNMNC), M. PASERO (Vice-Chairman, CNMNC) AND S. J. MILLS (Secretary, CNMNC) 1 School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia p.williams@uws.edu.au 2 Laboratoire de Minéralogie, Université de Liège, B-4000 Liège, Belgium fhatert@ulg.ac.be 3 Dipartimento di Scienze della Terra, Università degli Studi di Pisa, Via Santa Maria 53, I-56126 Pisa, Italy marco.pasero@unipi.it 4 Geosciences, Museum Victoria, PO Box 666, Melbourne, Victoria 3001, Australia smills@museum.vic.gov.au

Aluminopyracmonite, (NH4)3Al(SO4)3, a new ammonium aluminium sulfate from La Fossa crater, Vulcano, Aeolian Islands, Italy

Abstract The new mineral aluminopyracmonite, ideally (NH4)3Al(SO4)3, was found in a medium-temperature (~250ºC) intracrater active fumarole at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as colourless to white prismatic crystals up to 0.2 mm long, in association with adranosite, mascagnite, alunite and salammoniac. The mineral is identical to the synthetic compound (NH4)3Al(SO4)3. It is trigonal, space group: R3̅ (no. 148) with a = 15.0324(8), c = 8.8776(5) Å, V = 1737.3(2) Å3 and Z = 6. The six strongest reflections in the X-ray powder diffraction pattern are: [dobs in Å(I)(hkl)] 3.336(100)(131), 7.469(62)(1 1 0), 3.288(60)(122), 4.289(45)(2.31), 2.824(29)(3. 51) , 4.187(27)(012) . The empirical formula based on 12 anions is [(NH4)2.89K0.10] ∑2.99(Al1.18Fe0.01) ∑1.19S2.91O12, and the simplified formula (NH4,K)3Al(SO4)3. The measured density is 2.12(1) g/cm3, calculated density 2.143 g/cm3. The mineral is uniaxial(-) with ω = 1.545(3) and Ɛ = 1.532(3) (λ = 589 nm). Using single-crystal diffraction data, the structure was refined to a final R(F) = 0.0258 for 998 independent observed reflections [I > 2σ(I)]. In spite of having unit-cell parameters comparable with those of pyracmonite, the two minerals are not isostructural; the difference is related to a disordered conformation of the sulfate anions about the two independent Al3+ ions in aluminopyracmonite.

D’ansite-(Mn), IMA 2011-064. CNMNC Newsletter No. 11, December 2011

P. A. WILLIAMS (Chairman, CNMNC), F. HATERT (Vice-Chairman, CNMNC), M. PASERO (Vice-Chairman, CNMNC) AND S. J. MILLS (Secretary, CNMNC) 1 School of Natural Sciences, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia p.williams@uws.edu.au 2 Laboratoire de Minéralogie, Université de Liège, B-4000 Liège, Belgium fhatert@ulg.ac.be 3 Dipartimento di Scienze della Terra, Università degli Studi di Pisa, Via Santa Maria 53, I-56126 Pisa, Italy pasero@dst.unipi.it 4 Geosciences, Museum Victoria, GPO Box 666, Melbourne 3001, Victoria, Australia smills@museum.vic.gov.au

Cationic and anionic 1D chains based on NH+⋯N charge-assisted hydrogen bonds in bipyridyl derivatives and polyiodides

The possibility of constructing extended networks based on NH+⋯N charge-assisted hydrogen bonding and N⋯I interactions was explored. The organic modules 3,5-di-(3-pyridyl)-1,2,4-thiadiazole (L1) and 3,5-di-(4-pyridyl)-1,2,4-thiadiazole (L2) possess two pyridyl groups, allowing them to act both as hydrogen-bond acceptors and hydrogen-bond donors with H+ acting as the main linker between the molecular units. The crystal structure of the ionic compounds (HL1)I3, (HL1)I5, (HL1)IBr2, (HL2)I3, and (HL2)IBr2 are described; the position of the nitrogen atoms in the outwards pyridyl rings in L1 and L2 leads to the formation of 1D helices of interacting cations (HL1)+ and zig-zag chains of interacting cations (HL2)+. In the case of (HL1)I5, cationic helices of (HL1)+ and helices of I5− take place in a highly shape-complementary arrangement. The crystal structure of the bis-adduct L1·2I2 features the presence of intermolecular iodine–iodine long contacts to form infinite I2 chains. A comparative structural analysis carried out using the XPac procedure identifies three common molecular arrangements and confirms the importance of directional interactions and molecular shape of the target molecules in directing the packing preferences of this family of structures.

Argesite, (NH4)7Bi3Cl16, a new mineral from La Fossa Crater, Vulcano, Aeolian Islands, Italy: A first example of the [Bi2Cl10]4− anion

Abstract The new mineral argesite, ammonium bismuth chloride (NH4)7Bi3Cl16, was found in a mediumtemperature (~250 °C) active fumarole at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. The mineral occurs on a pyroclastic breccia as pale-yellow crystals up to 0.15 mm in length, in association with bismuthinite, adranosite, brontesite, demicheleite-(Br), demicheleite-(Cl), and panichiite. Argesite is trigonal, space group: R3̅c (no. 167) with Z = 18; the unit-cell parameters are (single-crystal data): a = 13.093(1), c = 102.682(1) Å, and V = 15245(2) Å3. The six strongest reflections in the X-ray powder diffraction pattern are: [dobs(Å) (I) (hkl)] 3.164 (100) (0 3 18), 3.808 (44) (2̅ 2 20), 2.742 (78) (2̅ 4 21), 6.14 (16) (1̅ 2 6), 1.906 (16) (0 0 5̅4̅), 1.686 (13) (5̅ 6 34). The mineral is uniaxial (-), with ω = 1.731(2), ε = 1.725(2) (589 nm). The IR spectrum shows absorptions at 3188(vs), 3060(s), and 1397(vs) cm-1, in agreement with the presence of the ammonium ion. Chemical analyses obtained by EDS electron microprobe gave (average wt%) Bi 42.26, Cl 32.57, Br 13.06, I 0.95, K 2.46, Tl 0.88, NH4 7.82 (by difference) total 100.00, corresponding to the empirical formula: [(NH4)6.29K0.91Tl0.06]Σ7.26Bi2.93(Cl13.33Br2.37I0.11)Σ15.81. The measured density is 2.88(1) g/cm3. The structure was refined, using single-crystal diffraction data, to a final R = 0.0345 for 1289 independent observed reflections [I > 2σ(I)]. It contains Bi2Cl4-10 and BiCl3-6 anions where the Bi atoms are octahedrally coordinated, and NH+4 cations are partially replaced by K+ and Tl+ ions.

Evidence of a correlation between magnetic and structural transitions in Y2−xZnxRu2O7 pyrochlore compounds

We report on an experimental investigation of the magnetic and structural properties of the Y2−xZnxRu2O7 pyrochlore system as a function of the Zn doping in the range 0.00 ≤ x ≤ 0.20. Magnetization and muon spin relaxation measurements show that the antiferromagnetic transition typical of the undoped compound at TN = 77 K is slightly reduced and broadened in the Zn doped sample. Extended X-ray absorption fine structure measurements show a peak in the Ru–O(1) first shell Debye–Waller factor at a temperature TDW ≈ TN, giving evidence for a strong magnetoelastic coupling detected up to x = 0.10. A local precursor order–disorder transition at T* > TN is also observed up to x = 0.10. For x > 0.10 these local structural features are hidden due to the increasing local lattice distortion induced by the Zn2+ dopant whereas the magnetic transition is still present.