Diaquabis(2,2'-dipyridylamine)M(II) Terephthalate Dihydrates, M(II) = Ni, Co: Synthesis, Crystal Structures, Thermal and Magnetic Properties.

Two new isostructural M(II) (M = Ni, Co) complexes with 2,2'-dipyridylamine (dipya) and dianion of terephthalic acid (H2tpht), [M(dipya)2(H2O)2](tpht) ∙ 2H2O, have been synthesized by ligand exchange reaction and characterized by single-crystal X-ray diffraction, FTIR spectroscopy, TG/DSC analysis and magnetic measurements. The crystal structures of [M(dipya)2(H2O)2](tpht) ∙ 2H2O consist of discrete complex units in which M(II) adopts deformed octahedral geometries. Two dipya ligands and two water molecules are coordinated to M(II) atom, tpht acts as a counter ion, while additional two water molecules remained uncoordinated. By numerous hydrogen bonds, all structural fragments are connected in three different chains which extend along [100], [010] and [001] directions, giving as a result a complex 3D network. The stabilization of 3D structure is accomplished by non-covalent face to face π-π interactions among pyridyl ring of dipya and benzene ring of tpht from adjacent chains. Towards the applied magnetic field, the both complexes exhibited almost perfect paramagnetic behavior.

Mixed-ligand MnII and CuII complexes with alternating 2,2'-bipyrimidine and terephthalate bridges.

The novel polymeric complexes catena-poly[[diaquamanganese(II)]-µ-2,2'-bipyrimidine-κ(4)N(1),N(1'):N(3),N(3')-[diaquamanganese(II)]-bis(µ-terephthalato-κ(2)O(1):O(4))], [Mn2(C8H4O4)2(C8H6N4)(H2O)4]n, (I), and catena-poly[[[aquacopper(II)]-µ-aqua-µ-hydroxido-µ-terephthalato-κ(2)O(1):O(1')-copper(II)-µ-aqua-µ-hydroxido-µ-terephthalato-κ(2)O(1):O(1')-[aquacopper(II)]-µ-2,2'-bipyrimidine-κ(4)N(1),N(1'):N(3),N(3')] tetrahydrate], {[Cu3(C8H4O4)2(OH)2(C8H6N4)(H2O)4]·4H2O}n, (II), containing bridging 2,2'-bipyrimidine (bpym) ligands coordinated as bis-chelates, have been prepared via a ligand-exchange reaction. In both cases, quite unusual coordination modes of the terephthalate (tpht(2-)) anions were found. In (I), two tpht(2-) anions acting as bis-monodentate ligands bridge the Mn(II) centres in a parallel fashion. In (II), the tpht(2-) anions act as endo-bridges and connect two Cu(II) centres in combination with additional aqua and hydroxide bridges. In this way, the binuclear [Mn2(tpht)2(bpym)(H2O)4] entity in (I) and the trinuclear [Cu3(tpht)2(OH)2(bpym)(H2O)4]·4H2O coordination entity in (II) build up one-dimensional polymeric chains along the b axis. In (I), the Mn(II) cation lies on a twofold axis, whereas the four central C atoms of the bpym ligand are located on a mirror plane. In (II), the central Cu(II) cation is also on a special position (site symmetry -1). In the crystal structures, the packing of the chains is further strengthened by a system of hydrogen bonds [in both (I) and (II)] and weak face-to-face π-π interactions [in (I)], forming three-dimensional metal-organic frameworks. The Mn(II) cation in (I) has a trigonally deformed octahedral geometry, whereas the Cu(II) cations in (II) are in distorted octahedral environments. The Cu(II) polyhedra are inclined relative to each other and share common edges.

Ionothermal synthesis and crystal structure of a new organic-inorganic hybrid compound: catena-poly[bis(1-ethyl-3-methylimidazolium) [hepta-µ-bromido-pentacuprate(I)]].

A new organic-inorganic hybrid compound, catena-poly[bis(1-ethyl-3-methylimidazolium) [µ5-bromido-tri-µ3-bromido-tri-µ2-bromido-pentacuprate(I)]], {(C6H11N2)2[Cu5Br7]}n, has been obtained under ionothermal conditions from a reaction mixture containing Ba(OH)2·8H2O, Cu(OH)2·2H2O, As2O5, 1-ethyl-3-methylimidazolium bromide and distilled water. The crystal structure consists of complex [Cu5Br7](2-) anions arranged in sinusoidal {[Cu5Br7](2-)}n chains running along the a axis, which are surrounded by 1-ethyl-3-methylimidazolium cations. Three of the five unique Br atoms and one of the three Cu(I) atoms occupy special positions with half-occupancy (a mirror plane perpendicular to the b axis, site symmetry m). The Cu(I) ions are in a distorted tetrahedral coordination environment, with four Br atoms at distances ranging from 2.3667 (10) to 2.6197 (13) Å, and an outlier at 3.0283 (12) Å, exceptionally elongated and with a small contribution to the bond-valence sum of only 6.7%. Short C-H···Br contacts build up a three-dimensional network. The Cu···Cu distances within the chain range from 2.8390 (12) to 3.0805 (17) Å, indicating the existence of weak Cu(I)···Cu(I) cuprophilic interactions.

Dirubidium hexaaquacobalt(II) tetrakis(hydrogen phthalate) tetrahydrate and coordination modes of the hydrogen phthalate anion.

The title compound, Rb2[Co(H2O)6](C8H5O4)4·4H2O, consists of nearly regular octahedral [Co(H2O)6]²âº cations with the CoII cations on the inversion centre (special position 2a), Rb⁺ cations, hydrogen phthalate (Hpht⁻) anions and disordered water molecules. The Rb⁺ cation is surrounded by nine O atoms from Hpht⁻ anions and water molecules, with a strongly deformed pentagonal-bipyramidal geometry and one apex split into three positions. The crystal packing is governed by numerous hydrogen bonds involving all water molecules and Hpht⁻) anions. In this way, layers parallel to the ab plane are formed, with the aromatic rings of the Hpht⁻ anions esentially directed along the c axis. While Hpht⁻ anions form the outer part of the layers, disordered water molecules and Rb⁺ cations alternate with [Co(H2O)6]²âº cations in the inner parts. The only interactions between the layers are van der Waals forces between the atoms of the aromatic rings. A search of the Cambridge Structural Database for coordination modes and types of hydrogen-bonding interaction of the Hpht⁻ anion showed that, when uncoordinated Hpht⁻ anions are present, compounds with intermolecular hydrogen bonds are more numerous than compounds with intramolecular hydrogen bonds. For coordinated Hpht⁻ anions, chelating and bridging anions are almost equally common, while monodentate anions are relatively scarce. The same coordination modes appear for Hpht⁻ anions with or without intramolecular hydrogen bonds, although intramolecular hydrogen bonds are less common.

Synthesis, characterization and antiproliferative activity of transition metal complexes with 3-(4,5-diphenyl-1,3-oxazol-2-yl)propanoic acid (oxaprozin).

A series of novel Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with oxaprozin (Hoxa), a non-steroidal anti-inflammatory drug, has been synthesized. The drug and complexes have been characterized by elemental and thermogravimetric (TG) analysis, Fourier transform (FT)-IR, 1H-NMR, 13C-NMR, UV-Vis spectroscopy and magnetic susceptibility measurements. The (pseudo)octahedral geometry has been proposed for all complexes based on electronic spectra and magnetic moments. With exception of the Cu(II) complex, where bridging bidentate mode of COO groups has been found, FT-IR spectra confirmed chelately coordinated COO groups in the other complexes. The general formula of the complexes is [M(H2O)2(oxa)2 ·χH2O, with χ=2 for M=Mn, Co and Ni and χ=1.5 for Zn. The binuclear Cu(II) complex, [Cu2(H2O)2(OH)(oxa)3]·2H2O, has strong Cu-Cu interactions of antiferromagnetic type. The complexes and Hoxa did not exhibit the cytotoxic effect to peritoneal macrophages. For the first time these complexes have been tested for their in vitro antiproliferative activity against human colon and breast cancer cell lines, HCT-116 and MDA-231, respectively. For all investigated compounds significant antiproliferative effects have been observed. Ni(II) complex has been shown to be a promising antiproliferative agent exerting excellent activity against HCT-116 even in nanomolar concentrations.

catena-Poly[[[(di-2-pyridylamine-κ2N2,N2')copper(II)]-µ-benzene-1,3-dicarboxylato-κ3O1,O1':O3] monohydrate], a zigzag coordination polymer with strong π-π interactions.

The novel title coordination polymer, {[Cu(C(8)H(4)O(4))(C(10)H(9)N(3))]·H(2)O}(n), synthesized by the slow-diffusion method, takes the form of one-dimensional zigzag chains built up of Cu(II) cations linked by benzene-1,3-dicarboxylate (ipht) anions. An exceptional characteristic of this structure is that it belongs to a small group of metal-organic polymers where ipht is coordinated as a bridging tridentate ligand with monodentate and chelate coordination of individual carboxylate groups. The Cu(II) cation has a highly distorted square-pyramidal geometry formed by three O atoms from two ipht anions and two N atoms from a di-2-pyridylamine (dipya) ligand. The zigzag chains, which run along the b axis, further construct a three-dimensional metal-organic framework via strong face-to-face π-π interactions and hydrogen bonds. A solvent water molecule is linked to the different carboxylate groups via hydrogen bonds. Thermogravimetric and differential scanning calorimetric analyses confirm the strong hydrogen bonding.

Substitutional and positional disorder in Sr(2.88)Cu(3.12)(PO4)4.

The title compound, a hydrothermally synthesized strontium copper(II) phosphate(V) (2.88/3.12/4), is isotypic with Sr(3)Cu(3)(PO(4))(4), obtained previously by solid-state reaction, but not with Sr(3)Cu(3)(PO(4))(4), obtained previously by the hydrothermal method. A surplus of copper was observed by both structural and chemical analysis, and the formula obtained by the structural analysis is in full agreement with results of the EDX (energy-dispersive X-ray diffraction) analysis. The structure consists of layers of Cu(3)O(12) groups which are linked via the PO(4) tetrahedra. The Cu(3)O(12) groups are formed by one Cu1O(4) and two Cu2O(5) coordination polyhedra sharing corners. The central Cu1 atom of the Cu(3)O(12) group is located at an inversion centre (special position 2a). The unique structural feature of the title compound is the presence of 12% Cu in the Sr1 site (special position 2b, site symmetry 1). Moreover, disordered Sr2 atoms were observed: a main site (Sr2a, 90%) and a less occupied site (Sr2b, 10%) are displaced by 0.48 (3) A along the b axis. Such substitutional and positional disorder was not observed previously in similar compounds.

Sodium citrate dihydrate doped with Mn3+ ions.

Sodium citrate dihydrate doped with Mn(3+) ions, namely trisodium(I) managnese(III) citrate(3-) dihydrate, [Na(3)Mn(0.011)(C(6)H(5)O(7))(H(2)O)(2)](n), was obtained during attempts to prepare some complex Mn(III) citrates from a concentrated strong alkaline solution containing Na(+), Mn(3+) and citrate ions. The compound is isostructural with the recently described Na(3)(C(6)H(5)O(7)).2H(2)O [Fischer & Palladino (2003). Acta Cryst. E59, m1080-m1082]. The essential difference between these two structures is the presence of a very small proportion (0.205 wt%) of Mn(3+) ions, which are positioned at the special 4e Wyckoff position in C2/c, where they are in a highly distorted octahedral environment of O atoms from two citrate anions.

Reinvestigation of Sr2[Cu(OH)6].

During an investigation of the SrO-CuO-P2O5-H2O system, single crystals of distrontium hexahydroxidocuprate(II), Sr2[Cu(OH)6], were obtained by the hydrothermal method. The blue prismatic crystals of Sr2[Cu(OH)6] adopt the same structure type as Ba2[Cu(OH)6], Sr2[Zn(OH)6] and Ba2[Zn(OH)6]. The Cu atoms, located at (0, 0, 1/2) (site symmetry 1), form mutually isolated and highly elongated Cu(OH)6 octahedra, which are interconnected to slightly distorted Sr(OH)6 trigonal prisms, forming a layered structure. The location of H atoms from difference Fourier maps and their refinement allowed the precise determination of a three-dimensional hydrogen-bonding network in which all hydroxide O atoms are involved. In addition, the hydrogen-bonding topologies in Sr2[Cu(OH)6] and other similar hexahydroxidometallates with the general formulae M1[M2(OH)6], M1(2)[M2(OH)6] and M1(3)[M2(OH)6] were analysed in detail.

Transition metal complexes with thiosemicarbazide-based ligands. LIII. [4-(2-Diphenylphosphino-alpha-ethoxybenzyl-kappaP)-S-methyl-1-(4-oxidopent-3-en-4-ylidene-kappaO)thiosemicarbazido-kappa(2)N(1),N(4)]nickel(II).

The title compound, [Ni(C(28)H(30)N(3)O(2)PS)], crystallizes with two independent molecules in the asymmetric unit. The Ni(II) atoms are in significantly deformed square-planar environments formed by an ONNP donor set from a thiosemicarbazide-based tetradentate ligand. The Ni(II) atom and the ONN donor atoms are nearly coplanar, while the P atom deviates from their mean planes by 0.278 (4) and 0.202 (4) Angstrom for the two independent molecules. The P-containing chelate rings are remarkably non-planar, adopting a boat conformation, which is unusual for chelate rings in transition metal complexes with thiosemicarbazide-based tetradentate ligands. The orientation of the ethoxy group bonded to this chelate ring is caused by an intramolecular C-H...pi interaction with the opposing phenyl ring. There are no hydrogen bonds; instead, numerous intermolecular C-H...pi interactions dominate in the crystal packing.

Cytotoxicity of some platinum(IV) complexes with ethylenediamine-N,N'-di-3-propionato ligand.

The cytotoxicities of two platinum(IV) complexes of formula [PtX2(eddp)].nH2O (eddp=ethylenediamine-N,N'-di-3-propionate, X=chloro [I] or bromo [II], n=1 or 1.24) are reported. The complexes have been obtained by direct reaction of potassium hexahaloplatinate(IV) with H2eddp.2HCl followed by addition of a base (LiOH). The crystal and molecular structure has confirmed that the complex with bromo ligands, similarly to the complex with chloro ligands previously reported, has trans configuration of the halogens. In both the chloro and bromo complexes there appear to be intramolecular N-H...X interactions which account for a narrowing of the corresponding X-Pt-N angles below 90degrees. The trans isomer (configuration index OC-6-13, two nitrogens and two oxygens of eddp bound in the equatorial plane) is the only one obtained in the reaction of hexahaloplatinate(IV) with the eddp ligand while a similar reaction performed with ethylenediamine-N,N'-diacetate (edda) affords exclusively the symmetrical cis-isomer (configuration index OC-6-33, equatorial nitrogen and axial oxygen atoms of edda). The longer chain of the propionato groups (as compared to the acetato ones) is responsible for such a change in preferred configuration. NMR data have revealed a very large diastereotopic splitting of the propionato methylene protons to the nitrogens (0.88 ppm). The trans disposition of the halogen ligands in the compounds with eddp leads to deactivation of platinum(IV) complexes in comparison to those with edda having cis disposition of the leaving chlorides (human ovarian cancer cell line A2780, IC50 [muM] of 92.6 +/- 12 and 30.3 +/- 7.5 for [I] and [II], respectively).

Dibromo(pyridoxal semicarbazone-kappa3N1,O3,O3')copper(II).

The title compound, dibromo(3-hydroxy-5-hydroxymethyl-2-methyl-4-pyridinecarboxaldehyde semicarbazone-kappa(3)N(1),O(3),O(3'))copper(II), [CuBr(2)(C(9)H(12)N(4)O(3))], consists of discrete complex units with the tridentate pyridoxal semicarbazone ligand as a zwitterion in an almost planar configuration. The Cu(II) ions are in a distorted square-pyramidal coordination, with the equatorial Br atom at a distance of 2.4017 (6) A and the apical Br atom at a distance of 2.6860 (6) A.

Comparison of two polymeric transition metal complexes with 1,4-benzenedicarboxylate ions as bridging ligands, [Co(C8H4O4)(C12H8N2)(H2O)] and [Cu(C8H4O4)(C10H9N3)].H2O.

The title complexes, catena-poly[[aqua(1,10-phenanthroline-kappa(2)N,N')cobalt(II)]-micro-benzene-1,4-dicarboxylato-kappa(2)O(1):O(4)], [Co(C(8)H(4)O(4))(C(12)H(8)N(2))(H(2)O)], (I), and catena-poly[[[(di-2-pyridyl-kappaN-amine)copper(II)]-micro-benzene-1,4-dicarboxylato-kappa(4)O(1),O(1'):O(4),O(4')] hydrate], [Cu(C(8)H(4)O(4))(C(10)H(9)N(3))].H(2)O, (II), take the form of zigzag chains, with the 1,4-benzenedicarboxylate ion acting as an amphimonodentate ligand in (I) and a bis-bidentate ligand in (II). The Co(II) ion in (I) is five-coordinate and has a distorted trigonal-bipyramidal geometry. The Cu(II) ion in (II) is in a very distorted octahedral 4+2 environment, with the octahedron elongated along the trans O-Cu-O bonds and with a trans O-Cu-O angle of only 137.22 (8) degrees.