Abstract
The reduction of [MoCl
3(TRI)], where TRI=PhP(CH
2CH
2PPh
2)
2, with sodium amalgam in benzene, toluene or anisole resulted in the formation of the corresponding [Mo(
ν
6-arene)(TRI)] complex. Each complex displayed a reversible one-electron oxidation in the cyclic voltammogram at ∼−1.0 V versus the ferrocenium/ferrocene couple at 0.0 V. corresponding to the oxidation of Mo(0) to Mo(1+). A second pseudo-reversible oxidation occurred at ∼0.7 V more positive. Monoprotonation of the arene complexes with CF
3COOH in THF resulted in the isolation of [Mo(H)(
ν
6-arene)[TRI)] [CF
3COO] (δ(MoH) ∼ −6 ppm). In neat CF
3COOH or HBF
4, evidence of diprotonation of the arene complexes was observed in the
1H NMR spectra. Upon work-up, only the monoprotonated product was isolated. [Mo(TRI)(P(OMe)
3)] was formed by the reduction of [MoCl
3(TRI)] in the presence of a small excess of P(OMe)
3. Attempts to prepare [Mo(TRI)(PMe)
3)
3] by a similar method resulted in a product that readily absorbed N
2 to form
fac-[Mo(N
2)(TRI)(PMe
3)
2]. Yellow [Mo(H) (
ν
5-C
5H
5) (TRI)] was formed by (i) the reduction of [MoCl
3(TRI)] with sodium amalgam in the presence of cyclopentadiene, or (ii) heating
fac-[Mo(N
2)(TRI)(PMe
3)
2] with cyclopentadiene in heptane, or (iii) heating
trans-[Mo(N
2)
2(TRI)(PPh
3)] with cyclopentadiene in THF.