The synthesis and coordination chemistry of pyrene and perylene containing ligands

A series of 1,3-, 1,6-, 1,8-, and 2,7-di-(2′-[1 ′,10′]-phenanthrolinyl)-pyrene ( 50–53) ligands were synthesized along with the tetrahydro-analogue to the 2,7-pyrene bridged isomer (49). The dinuclear Ru(II) complexes of 49–53 were prepared and analyzed by 1H NMR and X-ray crystallography, indicating that the bridging pyrene is layered between a bpy-d₈ auxiliary ligand coordinated to each metal atom. Although well situated for π-π interactions, there appears to be little such effect on the photophysical and electrochemical properties of these complexes.; A series of 3-, 5-, and 3,8-di-(1′-Ethynylpyrene)-1,10-phenanthroline (93–95) have been synthesized. The effects of the 1-ethynylpyrene group(s) on the photophysical and electrochemical properties varies with the position of substitution.; The bridged ligand 3,1′-dimethylene-2-(2 ′-pyrenyl)-1,10-phenanthroline (112H) was prepared and was found to cyclometalate at C1 of pyrene as well as affording the N5Cl complex. Both the N5C and the N5Cl complexes were analyzed by X-ray crystallography and the N5Cl species evidenced a congested environment for pyrene which is apparently stabilized by π-stacking with tpy.; The synthesis of 3-(2′-[1′,10 ′]-Phenanthrolinyl)perylene (136) and its Ru(II) complex are reported. For [Ru(136)(bpy-d ₈)₂]2+, the absorption spectra show characteristic perylene π-π* bands in the UV region shifted about 6 nm to longer wavelengths compared to 136. A series of three Ru(II) complexes of 1,12-diazaperylene (137) were prepared. The MLCT band is found at longer wavelength progressing from 552 to 576 to 588 nm with the successive complexation of additional molecules of 137.; The [Cu(112H)₂](PF₆) was prepared and its structure analyzed by 1H NMR. The aliphatic region shows four well-resolved signals corresponding to the α and α ′ methylene bridge. The minimum ligand exchange barrier is 16.3 Kcal/mol. Nickel promoted coupling was employed to synthesize the 6,6 ′-bi-phenanthridine (145). The X-ray structure of the [Cu(145)₂]+ complex showed a highly distorted coordination geometry with the phenanthridine rings involving N28 and N28′ lie almost parallel to one another.