Platinum(IV) Complexes of the 1,3,5-Triamino Analogue of the Biomolecule Cis-Inositol Designed as Innovative Antineoplastic Drug Candidates.

Metal complexes occupy a special place in the field of treatment and diagnostics. Their main advantages stem from the possibility of fine-tuning their thermodynamic properties and kinetic behavior in the biological milieu by applying different approaches such as properly constructed inner coordination sphere, appropriate choice of ligands, metal oxidation state, redox potential, etc., which are specific to these compounds.

Crystal structure and Hirshfeld surface analysis of tris-(2,2'-bi-pyridine)-nickel(II) bis-(1,1,3,3-tetra-cyano-2-eth-oxy-propenide) dihydrate.

The title compound, [Ni(CHN)](CHNO)·2HO, crystallizes as a racemic mixture in the monoclinic space group 2/. In the crystal, the 1,1,3,3-tetracyano-2-ethoxypropenide anions and the water molecules are linked by O-H⋯N hydrogen bonds, forming chains running along the [010] direction. The bpy ligands of the cation are linked to the chain C-H⋯π(cation) inter-actions involving the CH group.

HBr or not HBr? That is the question: crystal structure of 6-hydroxy-1,4-diazepane-1,4-diium dibromide redetermined.

Liu et al. [Chin. J.

Crystal structure of -bis-[bis-(pyridin-2-yl)methan-amine]-iron(II) 1,1,3,3-tetra-cyano-2-(di-cyano-methyl-idene)propane-1,3-diide, [Fe(dipa)](tcpd).

In the title compound, [Fe(CHN)](CN), the Fe cation is coordinated by two bis(pyridin-2-yl)methanamine (dipa) ligands and has crystallographic twofold symmetry. There are deviations from ideal octa-hedral geometry due to the steric requirements of the ligands. The polynitrile 1,1,3,3-tetra-cyano-2-(di-cyano-methylid-ene)propane-1,3-diide (tcpd) dianion is disordered about an inversion center and is not coordinated to the Fe atom.

Hafnium-Based Contrast Agents for X-ray Computed Tomography.

Heavy-metal-based contrast agents (CAs) offer enhanced X-ray absorption for X-ray computed tomography (CT) compared to the currently used iodinated CAs. We report the discovery of new lanthanide and hafnium azainositol complexes and their optimization with respect to high water solubility and stability. Our efforts culminated in the synthesis of BAY-576, an uncharged hafnium complex with 3:2 stoichiometry and broken complex symmetry.

Crystal structure of -di-μ-chlorido-bis-[bis-(2,2'-bi-pyridine)-cadmium] bis-(1,1,3,3-tetra-cyano-2-ethoxy-propenide) 0.81-hydrate.

The hydrated title salt, [CdCl(CHN)](CHNO)·0.81HO, was obtained from the hydro-thermal reaction between 2,2'-bi-pyridine, cadmium(II) chloride and potassium 1,1,3,3-tetra-cyano-2-eth-oxy-propenide. The binuclear cation lies across a centre of inversion in the space group 2/, with the other components in general positions.

Characterization of a Novel Hafnium-Based X-ray Contrast Agent.

Objective: Characterization of BAY-576, a new x-ray contrast agent which is not based on iodine, but rather on the heavy metal hafnium. Compared with iodine, hafnium provides better x-ray absorption in the energy range of computed tomography (CT) and allows images of comparable quality to be acquired at a significantly reduced radiation dose.

Materials And Methods: A range of standard methods were used to explore the physicochemistry of BAY-576 as well as its tolerability in in vitro assays, its pharmacokinetics and toxicology in rats, and its performance in CT imaging in rabbits.

Hydrogen-bonding patterns in bis[2,4,6-triazaniumylcyclohexane-1,3,5-tris(olate)-κ(3)O,O',O'']germanium(IV) tetrachloride hexahydrate.

A first preliminary report on the crystal structure of a hydrated salt formulated as [Ge(taci)2]Cl4·13H2O (taci is 1,3,5-triamino-1,3,5-trideoxy-cis-inositol) appeared more than 20 years ago [Ghisletta (1994). PhD thesis, ETH Zürich. Switzerland].

Formation of lithium, sodium and potassium complexes with 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci).

Single crystals of (1,3-diamino-5-azaniumyl-1,3,5-trideoxy-cis-inositol-κ(3)O(2),O(4),O(6))(1,3,5-triamino-1,3,5-trideoxy-cis-inositol-κ(3)O(2),O(4),O(6))lithium(I) diiodide dihydrate, [Li(C6H16N3O3)(C6H15N3O3)]I2·2H2O or [Li(Htaci)(taci)]I2·2H2O (taci is 1,3,5-triamino-1,3,5-trideoxy-cis-inositol), (I), bis(1,3,5-triamino-1,3,5-trideoxy-cis-inositol-κ(3)O(2),O(4),O(6))sodium(I) iodide, [Na(C6H15N3O3)2]I or [Na(taci)2]I, (II), and bis(1,3,5-triamino-1,3,5-trideoxy-cis-inositol-κ(3)O(2),O(4),O(6))potassium(I) iodide, [K(C6H15N3O3)2]I or [K(taci)2]I, (III), were grown by diffusion of MeOH into aqueous solutions of the complexes. The structures of the Na and K complexes are isotypic. In all three complexes, the taci ligands adopt a chair conformation with axial hydroxy groups, and the metal cations exhibit exclusive O-atom coordination.

Hydrogen bonding in polyamino-polyalcohols: a monohydrated cocrystal of 1,3-diamino-5-azaniumyl-1,3,5-trideoxy-cis-inositol iodide and 1,3,5-triamino-1,3,5-trideoxy-cis-inositol.

In the title monohydrated cocrystal, namely 1,3-diamino-5-azaniumyl-1,3,5-trideoxy-cis-inositol iodide-1,3,5-triamino-1,3,5-trideoxy-cis-inositol-water (1/1/1), C6H16N3O3(+)·I(-)·C6H15N3O3·H2O, the neutral 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci) molecule and the monoprotonated 1,3-diamino-5-azaniumyl-1,3,5-trideoxy-cis-inositol cation (Htaci(+)) both adopt a chair conformation, with the three O atoms in axial and the three N atoms in equatorial positions. The cation, but not the neutral taci unit, exhibits intramolecular O-H···O hydrogen bonding. The entire structure is stabilized by a complex three-dimensional network of intermolecular hydrogen bonds.

Formation and base hydrolysis of oxidimethaneamine bridges in CoIII-amine complexes.

cis-[CoL2](3+) (1a(3+)), trans-[CoL2](3+) (2a(3+)), cis-[Co(MeL)2](3+) (1b(3+)), and trans-[Co(MeL)2](3+) (2b(3+)), L = 1,4-diazepan-6-amine (daza) and MeL = 6-methyl-1,4-diazepan-6-amine (Medaza), were allowed to react as templates in acetonitrile with paraformaldehyde and triethylamine. Several Co(III) complexes, where two adjacent amino groups of two ligand moieties are interlinked by an oxidimethaneamine bridge, were obtained. Connection of a primary with a secondary amino group (prim-sec bridging) was found to be predominant.

Formation in aqueous solution of a non-oxido V(IV) complex with VN6 coordination. Potentiometric, ESI-MS, spectroscopic and computational characterization.

The behaviour of the system formed by V(IV)O(2+) ion with all-cis-2,4,6-trimethoxycyclohexane-1,3,5-triamine (tmca) was characterized in aqueous solution through the combined application of electron paramagnetic resonance (EPR) and UV-Vis spectroscopy, electrospray ionization mass spectrometry (ESI-MS), pH-potentiometry and DFT methods. The formation of an unusual non-oxido [V(tmcaH-2)2] species with VN6 coordination, with the ligand in the bianionic form, was demonstrated. The geometry, EPR and UV-Vis spectra and electronic structure of [V(tmcaH-2)2] were simulated with Gaussian 09 and ORCA software and the results were compared with those of similar oxido and non-oxido vanadium(iv) species formed by other polyamine and polyol related ligands, such as 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci), 1,3,5-trideoxy-1,3,5-tris(dimethylamino)-cis-inositol (tdci), cis-inositol (ino) and 1,3,5-trideoxy-1,3,5-trimethoxy-cis-inositol (tmci).

Poly[[(μ4-1,3,5-triamino-1,3,5-tride-oxy-cis-inositol)sodium] bromide].

In the structure of the title compound, {[Na(C6H15N3O3)]Br} n , the sodium cation and the bromide anion are both located on threefold rotation axes. The sodium cation is bonded to the three hy-droxy groups of one 1,3,5-triamino-1,3,5-tride-oxy-cis-inositol (taci) ligand, with the taci ligand residing around the same threefold rotation axis as the sodium ion. The coordination sphere of the sodium ion is completed by three amino groups of three neighbouring taci mol-ecules.

V(IV)O versus V(IV) complex formation by tridentate (O, N(arom), O) ligands: prediction of geometry, EPR 51V hyperfine coupling constants, and UV-Vis spectra.

Systems formed using the V(IV)O(2+) ion with tridentate ligands containing a (O, N(arom), O) donor set were described. Examined ligands were 3,5-bis(2-hydroxyphenyl)-1-phenyl-1H-1,2,4-triazole (H2hyph(Ph)), 4-[3,5-bis(2-hydroxyphenyl)-1H-1,2,4-triazol-1-yl]benzoic acid (H3hyph(C)), 4-[3,5-bis(2-hydroxyphenyl)-1H-1,2,4-triazol-1-yl]benzenesulfonic acid (H3hyph(S)), and 2,6-bis(2-hydroxyphenyl)pyridine (H2bhpp), with H3hyph(C) being an orally active iron chelator that is commercially available under the name Exjade (Novartis) for treatment of chronic iron overload arising from blood transfusions. The systems were studied using EPR, UV-Vis, and IR spectroscopies, pH potentiometry, and DFT methods.

3-Hy-droxy-2-meth-oxy-benzamide.

The crystal structure of the title compound, C8H9NO3, features centrosymmetric dimers with two amide groups inter-connected by a pair of almost linear N-H⋯O hydrogen bonds. Through inter-molecular O-H⋯O inter-actions between phenolic hy-droxy groups and carbonyl O atoms, these dimers are assembled into undulating hydrogen-bonded layers parallel to the [101] plane. Additionally, the anti-H(-N) atom of the primary amide group forms an intra-molecular hydrogen bond to the O atom of the meth-oxy group.

(S)-2,2'-Dihy-droxy-N,N'-(6-hy-droxy-hexane-1,5-di-yl)dibenzamide.

In the title compound, C(20)H(24)N(2)O(5), the dihedral angle between the two roughly planar salicyl-amide fragments [r.m.s.

Tris(cis-2-hy-droxy-cyclo-hexane-1,3,5-tri-aminium) hydrogen sulfate octa-chloride dihydrate.

The 2-hy-droxy-cyclo-hexane-1,3,5-triaminium (= H(3)L(3+)) cation of the title compound, 3C(6)H(18)N(3)O(3+)·8Cl(-)·HSO(4) (-)·2H(2)O, exhibits a cyclo-hexane chair with three equatorial ammonium groups and one axial hy-droxy group in an all-cis configuration. The hydrogen sulfate anion and two water mol-ecules lie on or in proximity to a threefold axis and are disordered. The crystal structure features N-H⋯Cl and O-H⋯Cl hydrogen bonds.

1,3-Diammonio-1,2,3-tride-oxy-cis-inositol sulfate.

In the crystal structure of the title compound, C(6)H(16)N(2)O(3) (2+)·SO(4) (2-), each cation forms three O-H⋯O and five N-H⋯O hydrogen bonds to six neighbouring sulfate anions. In addition, interlinking of the cations by N-H⋯O interactions is also observed. The cyclo-hexane ring adopts a chair conformation with two axial hy-droxy groups.

Redetermination of 1,3-diammonio-1,2,3-tride-oxy-cis-inositol dichloride.

The crystal structure of the title compound, C(6)H(16)N(2)O(3) (2+)·2Cl(-), has been reported previously by Palm [Acta Cryst. (1967 ▶), 22, 209-216] from Weisenberg camera data, with R1 = 10.5%, isotropic refinement of non-H atoms and H atoms not located.

4,6-Dinitro-pyrogallol.

In the title mol-ecule, C(6)H(4)N(2)O(7), the two nitro groups are tilted with respect to the aromatic ring by 11.2 (1) and 10.9 (1)°.

1,2,3-Trimeth-oxy-4,5,6-trinitro-benzene.

In the title mol-ecule, C(9)H(9)N(3)O(9), the three neighbouring nitro groups are tilted with respect to the benzene mean plane by 75.8 (1), 27.7 (1) and 68.

Facially coordinating triamine ligands with a cyclic backbone: some structure-stability correlations.

Metal complex formation of the two cyclic triamines 6-methyl-1,4-diazepan-6-amine (MeL(a)) and all-cis-2,4,6-trimethylcyclohexane-1,3,5-triamine (Me(3)tach) was studied. The structure of the free ligands (H(x)MeL(a))(x+) and H(x)Me(3)tach(x+) (0 ≤ x ≤ 3) was investigated by pH-dependent NMR spectroscopy and X-ray diffraction experiments. The crystal structure of (H(2)Me(3)tach)(p-O(3)S-C(6)H(4)-CH(3))(2) showed a chair conformation with axial nitrogen atoms for the doubly protonated species.

Chelation versus binucleation: metal complex formation with the hexadentate all-cis-N1,N2-bis(2,4,6-trihydroxy-3,5-diaminocyclohexyl)ethane-1,2-diamine.

The hexadentate ligand all-cis-N(1),N(2)-bis(2,4,6-trihydroxy-3,5-diaminocyclohexyl)ethane-1,2-diamine (L(e)) was synthesized in five steps with an overall yield of 39% by using [Ni(taci)(2)]SO(4).4H(2)O as starting material (taci=1,3,5-triamino-1,3,5-trideoxy-cis-inositol). Crystal structures of [Na(0.

fac-{2-[Bis(2-amino-eth-yl)amino]-ethanaminium}trichloridorhodium(III) chloride hemihydrate.

The crystal structure of the title compound, [Rh(C(6)H(19)N(4))Cl(3)]Cl·0.5H(2)O, is isotypic with the previously reported Ru analogue. The structure contains two crystallographically independent [Rh(Htren)Cl(3)](+) cations with a facial tridentate coordination of the monoprotonated tren ligand [tren = tris-(2-amino-eth-yl)amine], leading to an overall distorted octahedral coordination environment around the Rh(III) atom.

Characteristic spin-orbit induced 1H(CH2) chemical shifts upon deprotonation of group 9 polyamine aqua and alcohol complexes.

The recently observed nonintuitive pH dependence of methylene (1)H chemical shifts in cobalt(III) polyamine complexes upon deprotonation of coordinated aqua or (poly)alcohol coligands (J. Am. Chem.