Synthesis and reactivity of Ru(II) complexes containing the phosphino-amine Ph2PCH2CH2NMe2

Article abstract of DOI:10.1016/S0020-1693(97)05721-6

RuCl₃ · 3H₂O reacts with 2 equiv. of Ph₂PCH₂CH₂NMe₂ in the presence of Zn to the neutral complex Ru(κ²(P,N)-Ph₂PCH₂CH₂NMe ₂)₂Cl₂ (1). Alternatively, 1 is also obtained by the reaction of RuCl₂(PPh₃)₃ with 2 equiv. of Ph₂PCH₂CH₂NMe₂. Compound 1 crystallizes in the space group P2₁ (No. 4) with a = 11.009(3), b = 11.007(4), c = 16.999(4) A, β = 106.22(2)° and Z = 2. The hemilabile nature of the Ph₂PCH₂CH₂NMe₂ ligand in 1 is revealed by the reaction with CO and HC ≡ CPh affording complexes Ru(κ²(P,N)-Ph₂PCH₂CH₂NMe ₂)-(κ¹(P)-Ph₂PCH₂CH ₂NMe₂)(Cl)₂(CO) (2) and Ru(κ²(P,N)-Ph₂PCH₂CH₂NMe ₂) (κ¹(P)-Ph₂PCH₂CH₂NMe ₂)(Cl)₂(=C=CHPh) (3). Halide abstraction from 1 with NaBPh₄ affords the five-coordinate cationic complex [Ru(κ²(P,N)-Ph₂PCH₂CH₂NMe ₂)₂Cl]⁺ [BPh₄]^- (4) which crystallizes in the space group Pbca (No. 61) with a = 21.806(4), b = 19.683(4), c = 26.405(5) A, and Z = 8. Compound 4 reacts readily with CH₃CN, CO and HC ≡ CR (R = Ph, SiMe₃, n-Bu) to give the cationic complexes [Ru(κ²(P,N)-Ph₂PCH₂CH₂NMe ₂)₂(Cl)-(CH₃CN)]⁺ (5), [Ru(κ₂(P,N)-Ph₂PCH₂CH₂NMe ₂)₂(Cl)(CO)]⁺ (6), and [Ru(κ²(P,N)-Ph₂PCH₂CH₂NMe ₂)₂(Cl)(=C=CHR)]⁺ (7-9). Compound [Ru(κ²(P,N)-Ph₂PCH₂CH₂NMe ₂)₂(Cl)(CO)]⁺ [BPh₄]^- (6a) one of the two stereoisomers 6a and 6b crystallizes in the space group P1 (No. 2) with a = 11.637(3), b = 15.012(3), c = 15.306(3) A, α = 96.34(1), β = 98.32(1), γ = 98.73(1)° and Z = 2 and the isomeric compound 6b crystallizes in the space group P2₁/c (No. 14) with a = 20.445(2), b = 14.198(2), c = 19.717(2) A, β = 94.66(1)° and Z = 4. 1 catalyzes the dimerization of HC ≡ CPh to Z- and E-butenynes.