Solid-state self-assembly of polymeric double helicates leading to linear arrays of silver(I) ions and reversible strand/double helix interconversion in solution.
Reaction of a bent py-hyz-pym-hyz-pym 1 and of a linear py-hyz-py-hyz-pym 3 (py=pyridine; pym=pyrimidine; hyz=hydrazone) ligand strands with silver(I) tetrafluoroborate in CH(3)NO(2) generates double-helical dinuclear 2 and trinuclear 4 complexes. These complexes form polymeric, highly ordered solid-state structures, with wirelike, linear continuous or discontinuous polycationic Ag(n) (+) arrays with Ag--Ag distances of 2.78 to 4.42 A. Ligand 5, an isomer of 1, is found to yield a [2x2] grid-type complex 6. Titration experiments reveal the formation of linear rack-type dinuclear species from 1 and 5. Acid-base modulated, reversible interconversion between strand 1 and double helicate 2 may be achieved by using tren as a competing complexing agent (tren=N(CH(2)CH(2)NH(2))(3)). Progressive addition of silver(I) ions to a 1:1 mixture of 1 and 5 leads to the preferential formation of the double helicate 2 over the grid complex 6, illustrating a process of self-organisation with selection of the correct ligand.
Stadler
Adrian-Mihail
AM
Laboratoire de Chimie Supramoléculaire, ISIS, Université Louis Pasteur, 8 Allée Gaspard Monge, BP 70028, 67083 Strasbourg Cedex, France.
Kyritsakas
Nathalie
N
Vaughan
Gavin
G
Lehn
Jean-Marie
JM
D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D012996:Solutions
D002412:Cations; D008024:Ligands; D011108:Polymers; D012996:Solutions; D012834:Silver