Novel three-dimensional coordination polymer of 2-(1,3,5-tri-aza-7-phospho-niatri-cyclo-[3.3.1.13,7]decan-7-yl)ethanoic acid with silver(I) tetra-fluoro-borate.

An AgI-based coordination polymer (CP), namely, poly[[[µ3-2-(1,3,5-tri-aza-7-phospho-niatri-cyclo-[3.3.1.13,7]decan-7-yl)ethano-ate-κ4 N:N':O,O']silver(I)] tetra-fluoro-borate], {[Ag(C9H16N3O2P)]BF4} n , was synthesized in an aqueous solution of zwitterionic 2-(1,3,5-tri-aza-7-phospho-niatri-cyclo-[3.3.1.13,7]decan-7-yl)ethan-o-ate (L) and AgBF4 with exclusion of light at room temperature. The colourless and light-insensitive CP crystallized in the monoclinic space group Cc. The asymmetric unit consists of an AgI cation, the zwitterionic L ligand and a BF4 - counter-ion. Each AgI ion is coordinated by two carboxyl-ate oxygen atoms in a chelating coordination mode, as well as one of the nitro-gen atoms of two neighbouring L ligands. The crystal structure of the CP was classified as a unique three-dimensional arrangement. The CP was also characterized in aqueous solutions by multinuclear NMR and HRMS spectroscopies and elemental analysis.

Exploring Cyclic Aminopolycarboxylate Ligands for Sb(III) Complexation: PCTA and Its Derivatives as a Promising Solution.

In recent years Auger electron emitters have been suggested as promising candidates for radiotherapy with no side effects in cancer treatment. In this work we report a detailed coordination chemistry study of [Sb(PCTA)] (PCTA: 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-3,6,9-triacetic acid), a macrocyclic aminopolycarboxylate-type complex of antimony(III), whose 119Sb isotope could be a suitable low-energy electron emitter for radiotherapy. The thermodynamic stability of the chelate obtained by pH-potentiometry and UV-vis spectrophotometry is high enough (log K[Sb(PCTA)] = 23.2(1)) to prevent the hydrolysis of the metal ion near physiological pH. The formation of [Sb(PCTA)] is confirmed by NMR and electrospray ionization mass spectrometry measurements in solution; furthermore, the structure of [Sb(PCTA)]·NaCl·3H2O and [Sb(PCTA)]·HCl·3H2O is described by X-ray and density functional theory calculations. Consequently, the [Sb(PCTA)] is the first thermodynamically stable antimony(III) complex bearing polyamino-polycarboxylate macrocyclic platform. Our results demonstrate the potential of rigid (pyclen derivative) ligands as chelators for future applications of Sb(III) in a targeted radiotherapy based on the 119Sb isotope.

Crystal structure of levomepromazine maleate.

The asymmetric unit of the title salt, C19H25N2OS(+)·C4H3O4 (-) [systematic name: (S)-3-(2-meth-oxy-pheno-thia-zin-10-yl)-N,N,2-tri-methyl-propanaminium hydrogen maleate], comprises two (S)-levomepromazine cations and two hydrogen maleate anions. The conformations of the two cations are similar. The major difference relates to the orientation of the meth-oxy substituent at the pheno-thia-zine ring system. The crystal components form a three-dimensional supra-molecular network via N-H⋯O, C-H⋯O and C-H⋯π inter-actions. A comparison of the conformations of the levomepromazine cations with those of the neutral mol-ecule and similar protonated mol-ecules reveals significant conformational flexibility of the pheno-thia-zine ring system and the substituent at the pheno-thia-zine N atom.

Crystal structure of diethyl 3-(3-chloro-phen-yl)-2,2-di-cyano-cyclo-propane-1,1-di-carboxyl-ate.

In the racemic title compound, C17H15ClN2O4, which has been synthesized and the crystal structure of the solvent-free mol-ecule determined, the angle between the planes of the benzene and cyclo-propane rings is 54.29 (10)°. The mol-ecular conformation is stabilized by two weak intra-molecular C-H⋯Ocarbox-yl inter-actions. In the crystal, C-H⋯O hydrogen bonds form centrosymmetric cyclic R 2 (2)(10) dimers which are linked into chain substructures extending along c. Further C-H⋯Nnitrile hydrogen bonding, including a centrosymmetric cyclic R 2 (2)(14) association, link the chain substructures, forming a two-dimensional layered structure extending across the approximate ab plane. No significant π-π or halogen-halogen inter-molecular inter-actions are present in the crystal.

Crystal structure of diethyl 2-acet-oxy-2-[3-(4-nitro-phen-yl)-3-oxo-1-phenyl-prop-yl]malonate.

In the racemic title compound, C24H25NO9, the dihedral angle between the planes of the two benzene-ring systems is 80.16 (6)°, while the side-chain conformation is stabilized by a methyl-ene-carboxyl C-H⋯O hydrogen bond. Weak inter-molecular C-H⋯O hydrogen bonds form inversion dimers [graph set R 2 (2)(16)] which are linked into chains extending along a. Further C-H⋯O hydrogen bonding extends the structure along b through cyclic R 2 (2)(10) motifs. Although no π-π aromatic ring inter-actions are present in the structure, C-H⋯π ring inter-actions across c generate an overall three-dimensional supra-molecular structure.