234767-72-7Relevant academic research and scientific papers
Effects of sterics and electronic delocalization on the photophysical, structural, and electrochemical properties of 2,9-disubstituted 1,10-phenanthroline copper(I) complexes
Miller, Mark T.
, p. 3414 - 3422 (2008/10/08)
The syntheses, crystal structures, electronic absorption spectra, electrochemical properties, and photophysical properties of a series of copper(I) bis(phenanthroline) complexes are reported. The phenanthroline ligands that have been prepared and investigated are the following: dop (2,9-di-(2-methylphenyl)-1,10-phenanthroline), xop (2-(2-methylphenyl)-9-(2,6-dimethylphenyl)-1,10-phenanthroline), dpep(2,9-diphenylethynyl-1,10-phenanthroline), and dmesp (2,9-dimesityl-1,10-phenanthroline). The complex [Cu(dop)2](PF6)·Et2O crystallizes in space group P1with a = 11.854(3) A, b = 14.705(3) A, c = 15.866(4) A, α = 107.81(2)°, β= 106.72(2)°, γ = 97.56(2)°, V = 2447.6(10) A3, and Z = 2. For 5739 unique data with F > 4.0σ(F), R = 7.52%. The complex [Cu(xop)2](PF6)·3/2CH3OH crystallizes in space group C2/c with a = 23.096(6) A, b = 23.387(6) A, c = 17.873(7) A, β = 100.08(3)°, V = 9505(5) A3, and Z = 8. For 5631 unique data with F > 4.0σ(F), R = 6.02%. The complex [Cu(dpep)2](PF6) crystallizes in space group P1 with a = 13.327(7) A, b = 14.114(7) A, c = 15.175(5) A, α = 87.23(4)°, β= 66.48(3)°, γ = 61.84(4)°, V = 2273(2) A3, and Z = 2. For 4851 unique data with F > 4.0σ(F) R = 5.47%. The complex [Cu(dmesp)(dpep)](PF6) crystallizes in space group Pbca with a = 14.547(6) A, b = 22.868(6) A, c = 30.659(10) A, V = 10199(6) A3, and Z = 8. For 2281 unique data with F > 4.0σ(F), R = 9.43%. The electrochemical, spectral, and structural properties of [Cu(dop)2]+ and [Cu(xop)2]+ demonstrate that the copper coordination environment is more sterically encumbered and more rigid in these two complexes than the coordination environment in the comparison molecule [Cu(dpp)2]+ (dpp = 2,9-diphenyl-1,10-phenanlhroline). A larger energy gap is predicted for [Cu(dop)2]+ and [Cu(xop)2]+ based on these data, and consequently, a blue-shifted emission is observed relative to [Cu(dpp)2]+. The room-temperature excited-state lifetimes in dichloromethane and methanol of the dop and xop complexes are shown to be shorter than the dpp complex, and these results are interpreted as due to a reduction in ligand π-electron delocalization in the former two complexes. The complexes [Cu(dpep)2]+ and [Cu(dmesp)(dpep)]+ are shown to have increased ligand π-electron delocalization relative to [Cu(dpp)2]+; however, neither complex displays room-temperature steady-state emission in dichloromethane.
