| Abstract
| - A series of cyclic metalloporphyrin trimers containing one Ru(II)−CO porphyrin center are synthesized. A stepwiseconvergent route is used to synthesize Ru(CO)Zn22·Py3T, where tripyridyltriazine (Py3T) templates the formationof the trimer and forces the CO group to the outside of the cavity. Three mixed-metal trimers, Ru(CO)Zn22,Ru(CO)Ni22, and Ru(CO)Mg22, are synthesized from Ru(CO)Zn22·Py3T and are characterized by NMR, UV−visible, and fluorescence spectroscopy. The Ru(CO)Zn22 trimer is found to bind Py3T very tightly (K ≈ 1012M-1), the resultant complex dissociating very slowly (kdissoc ≈ 3 × 10-7 s-1) in CDCl3 at 60 °C. During thecourse of these studies, the binding selectivity of a ruthenium porphyrin monomer, Ru(CO)3, for pyridine overTHF is estimated to be ca. 7 × 104:1.
- A series of cyclic metalloporphyrin trimers containing one Ru(II)−CO porphyrin center are synthesized. Tripyridyltriazine (Py3T) both templates the formation of the parent complex Ru(CO)Zn22·Py3T and forces the CO group to the outside of the cavity. Three mixed-metal trimers, Ru(CO)Zn22, Ru(CO)Ni22, and Ru(CO)Mg22, are synthesized from Ru(CO)Zn22·Py3T. Binding studies of these trimers and a ruthenium porphyrin monomer provide insights into the kinetics of ligand exchange and binding selectivities of ruthenium porphyrins.
|
