A new oxidation-based synthetic route was developed for synthesis of Cu(I) complexes with weakly coordinatingligands, leading to the synthesis of the elusive [Cu(
dtbp)
2]
+ (
dtbp, 2,9-di-
tert-butyl-1,10-phenanthroline) complexthat may be useful as a sensor or as a dye for dye-sensitized solar cells. An acetone solution of either 1 or 2 equivof
dtbp was added to excess Cu(0) and 1 equiv of AgY (Y is O
3SCF
3-, BF
4-, SbF
6-, or B(C
6F
5)
4-) in a nitrogen-filled glove box. Following filtration and evaporation under vacuum, crystallization from CH
2Cl
2 and hexanes resultsin X-ray quality crystals of Cu(
dtbp)(O
3SCF
3) (
1), Cu(
dtbp)(BF
4) (
2), [Cu(
dtbp)(acetone)][SbF
6] (
3), [Cu(
dtbp)
2][B(C
6F
5)
4]
![](/images/entities/bull.gif)
CH
2Cl
2 (
4
CH2Cl2), [Cu(
dtbp)
2][BF
4]
![](/images/entities/bull.gif)
CH
2Cl
2 (
5
CH2Cl2), and [Cu(
dtbp)
2][SbF
6]
![](/images/entities/bull.gif)
CH
2Cl
2 (
6
CH2Cl2).Complexes
1-
6 were characterized by X-ray crystallography and NMR. The Cu atom in complexes
1-
3 exhibiteddistorted trigonal coordination geometries, reflecting the steric effect of the bulky
tert-butyl substituents. The structuresof the pseudotetrahedral complexes
4,
4
CH2Cl2,
5
CH2Cl2, and
6
CH2Cl2 revealed the longest average Cu-Ndistances (2.11 Å, 2.11 Å, 2.10 Å, and 2.11 Å, respectively) in this class of compounds-longer by more than threestandard deviations from the average.