om300567v_si_002.cif (85.24 kB)
Copper(I) Ethylene Complexes Supported by 1,3,5-Triazapentadienyl Ligands with Electron-Withdrawing Groups
dataset
posted on 2012-11-26, 00:00 authored by Venkata
A.K. Adiraju, Jaime A. Flores, Muhammed Yousufuddin, H. V. Rasika DiasThe fluorinated 1,3,5-triazapentadienyl ligands [N{(C3F7)C(2-(NO2)C6H4)N}2]−, [N{(C3F7)C(4-(NO2)C6H4)N}2]−, [N{(C3F7)C(2-(CF3)C6H4)N}2]−, and
[N{(C3F7)C(2-F,6-(CF3)C6H3)N}2]− have been used as
supporting ligands
in copper(I) ethylene chemistry. [N{(C3F7)C(2-(NO2)C6H4)N}2]Cu(C2H4) (7), [N{(C3F7)C(4-(NO2)C6H4)N}2]Cu(C2H4) (8), [N{(C3F7)C(2-(CF3)C6H4)N}2]Cu(C2H4) (9), and [N{(C3F7)C(2-F,6-(CF3)C6H3)N}2]Cu(C2H4) (10) are easily isolable,
thermally stable solids
and display their ethylene proton and carbon resonances in the δ
3.68–3.48 and 85.2–87.6 ppm regions, respectively. X-ray
crystal structures reveal that 7–10 feature trigonal-planar copper sites and κ2-bonded,
U-shaped triazapentadienyl ligands. The Cu(I) carbonyl adducts [N{(C3F7)C(2-(NO2)C6H4)N}2]Cu(CO)(NCCH3) (16) and [N{(C3F7)C(4-(NO2)C6H4)N}2]Cu(CO)(NCCH3) (17) have also
been synthesized, and they have pseudotetrahedral copper sites. The
CO stretching frequencies of the compounds 16 and 17 and ethylene 13C NMR chemical shift data of 7–10 suggest that these molecules have
rather acidic copper sites and weakly donating triazapentadienyl ligands.
