RESUMO
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.
RESUMO
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.
Assuntos
Antimônio/química , Complexos de Coordenação/química , Teoria da Densidade Funcional , Ligantes , Modelos Moleculares , Estrutura Molecular , SoluçõesRESUMO
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-Hâ¯O, C-Hâ¯O and C-Hâ¯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.
RESUMO
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 54.29â (10)°. The mol-ecular conformation is stabilized by two weak intra-molecular C-Hâ¯Ocarbox-yl inter-actions. In the crystal, C-Hâ¯O hydrogen bonds form centrosymmetric cyclic R 2 (2)(10) dimers which are linked into chain substructures extending along c. Further C-Hâ¯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.
RESUMO
In the racemic title compound, C24H25NO9, the dihedral angle between the planes of the two benzene-ring systems is 80.16â (6)°, while the side-chain conformation is stabilized by a methyl-ene-carboxyl C-Hâ¯O hydrogen bond. Weak inter-molecular C-Hâ¯O hydrogen bonds form inversion dimers [graph set R 2 (2)(16)] which are linked into chains extending along a. Further C-Hâ¯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-Hâ¯π ring inter-actions across c generate an overall three-dimensional supra-molecular structure.