0000000000033465
AUTHOR
Manuel Querol
Outer and inner coordination sphere chemistry of polyazacyclophane platinum(II) complexes. Crystal structure of [PtBr4]2(H4L1) · H2O (L1 = 2,6,9,13-tetraaza[14]paracyclophane)
Abstract The interaction of PtCl42− with the new azaparacyclophane 2,5,8,11-tetraaza[12]paracyclophane (L2) has been studied by 1H, 13C and 195Pt NMR spectroscopy. Three different complexes are detected as a function of pH, all of them presenting cis-arrangement of nitrogen donors and chloride anions. In the first one, formed at acidic pH, the central nitrogen atoms of the macrocyclic are coordinating to Pt(II) while the benzylic nitrogens remain protonated. Deprotonation of these nitrogens brings about a reorganisation of the complex, and the platinum is then coordinated by one benzylic nitrogen and the consecutive nitrogen in the macrocycle. This process can be monitored by NMR. Finally, …
Thermodynamics of sulfate anion binding by macrocyclic polyammonium receptors
The interaction of SO42− with polyammonium cations derived from fourteen polyamines (5 polyazacycloalkanes, 2 polyazacyclophanes, 3 phenanthrolinacyclophanes, 2 dibenzenacyclophanes and 2 acyclic polyamines) in aqueous solution has been studied by means of potentiometric and microcalorimetric techniques. Only 1 : 1 receptor–anion complexes have been found in solution. Complexed species of considerable stability are formed, although the two acyclic polyamines (dimethylpentaethylenehexaamine and dimethylhexaethyleneheptaamine) and the smallest phenanthrolinacyclophane do not interact with the anion. The complexation reactions are endothermic, or almost athermic, and promoted by invariably fav…
One-pot synthesis of polyaza[n]naphthalenophanes and polyaza[n]anthracenophanes
Abstract Pernosylated polyaza[n]cyclophanes 13–20 were prepared by a Richman-Atkins modified methodology. Deprotection under mild conditions gave polyaza[n]cyclophanes 21–28 . This methodology allows for the preparation of cyclophanes containing labile C-N bonds.
A polyazacyclophane containing two biphenyl subunits as a versatile cation and anion receptor
Abstract The synthesis, protonation behaviour and coordination capabilities towards Cu 2+ , Zn 2+ and towards the nucleotides ATP and ADP of a cyclophane ditopic receptor 2,6,10,23,27,31-hexaaza[11,11](2,2′)biphenylophane containing two 2,2′-biphenylene spacers linked to the ends of 1,5,9-triazanonane chains are presented.