Addition of secondary and primary amines to the allenylidene ligand of [Ru(η5-C5H5)(C=C=CPh2) (CO)(PiPr3)]BF4:: Synthesis of azoniabutadienyl, aminoallenyl, and azabutadienyl derivatives of ruthenium(II)

The allenylidene complex [Ru(eta(5)-C5H5)(C=C=CPh2)(CO)((PPr3)-Pr-i)] BF4 (1) reacts with diethylamine and piperidine to give the azoniabutadienyl derivatives [Ru(eta(5)-C5H5){C(CH=CPh2)=NEt2}(CO)((PPr3)-Pr-i)]BF4 (2) and [Ru(eta(5)-C5H5) {C(CH=CPh2)=NCH2(CH2)(3)CH2}(CO)-((PPr3)-Pr-i)]BF4 (3), respectively. The molecular structure of 2 has been determined by X-ray crystallography. The geometry around the ruthenium center is close to octahedral with the cyclopentadienyl ligand occupying three sites of a face. The Ru-C-alpha bond length is 2.063(6) Angstrom, whereas the C-alpha-N distance is 1.306(7) Angstrom. Treatment of 2 and 3 with sodium methoxide produces the deprotonation of the CH=CPh2 fragment to afford the aminoallenyl derivatives Ru(eta(5)-C5H5){C(NEt2)=C=CPh2}(CO)((PPr3)-Pr-i) (4) and Ru(eta(5)-C5H5){C(NCH2(CH2)(3)CH2)=C= CPh2)(CO)((PPr)-Pr-i)(3) (5). Complex 1 also reacts with n-propylamine and aniline. In this case, the reaction products are [Ru(eta(5)-C5H5){C(CH=CPh2)=(NHPr)-Pr-n}(CO)((PPr3)-Pr-i)]BF4 (6) and [Ru(eta(5)-C5H5){C(CH=CPh2)=NHPh}(CO)((PPr3)-Pr-i) BF4 (7). Treatment of 6 and 7 with sodium methoxide produces the deprotonation of the nitrogen atom of the unsaturated yl-carbon ligand, to give the azabutadienyl compounds Ru(eta(5)-C5H5){C(CH=CPh2)=(NPr)-Pr-n}(CO)((PPr3)-Pr-i) (8) and Ru(eta(5)-C5H5){C(CH=CPh2)=NPh}(CO)((PPr3)-Pr-i) (9), respectively. The ellipticities of the Ru-C-alpha and C-alpha-N bonds of the model compounds [Ru(eta(5)-C5H5){C(CH=CH2)=NH2}(CO)- (PH3)](+) (10), Ru(eta(5)-C5H5){C(NH2)=C=CH2}(CO)(PH3) (11), and Ru(eta(5)-C5H5){C(CH=CH2)= NH}(CO)(PH3) (12) have been studied using the AIMPAC series of programs. The obtained values are 0.07 and 0.12 (10), 0.05 and 0.07 (11), and 0.07 and 0.10 (12), respectively.