Addition of Secondary and Primary Amines to the Allenylidene Ligand of [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4: Synthesis of Azoniabutadienyl, Aminoallenyl, and Azabutadienyl Derivatives of Ruthenium(II)

The allenylidene complex [Ru(η 5 -C 5 H 5 )(C C CPh 2 )(CO)(P i Pr 3 )]BF 4 ( 1 ) reacts with diethylamine and piperidine to give the azoniabutadienyl derivatives [Ru(η 5 -C 5 H 5 ){C(CH CPh 2 ) NEt 2 }(CO)(P i Pr 3 )]BF 4 ( 2 ) and ( 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 α bond length is 2.063(6) Å, whereas the C α −N distance is 1.306(7) Å. Treatment of 2 and 3 with sodium methoxide produces the deprotonation of the CH CPh 2 fragment to afford the aminoallenyl derivatives Ru(η 5 -C 5 H 5 ){C(NEt 2 ) C CPh 2 }(CO)(P i Pr 3 ) ( 4 ) and ( 5 ). Complex 1 also reacts with n -propylamine and aniline. In this case, the reaction products are [Ru(η 5 -C 5 H 5 ){C(CH CPh 2 ) NH n Pr}(CO)(P i Pr 3 )]BF 4 ( 6 ) and [Ru(η 5 -C 5 H 5 ){C(CH CPh 2 ) NHPh}(CO)(P i Pr 3 )]BF 4 ( 7 ). Treatment of 6 and 7 with sodium methoxide produces the deprotonation of the nitrogen atom of the unsaturated η 1 -carbon ligand, to give the azabutadienyl compounds Ru(η 5 -C 5 H 5 ){C(CH CPh 2 ) N n Pr}(CO)(P i Pr 3 ) ( 8 ) and Ru(η 5 -C 5 H 5 ){C(CH CPh 2 ) NPh}(CO)(P i Pr 3 ) ( 9 ), respectively. The ellipticities of the Ru−C α and C α −N bonds of the model compounds [Ru(η 5 -C 5 H 5 ){C(CH CH 2 ) NH 2 }(CO)(PH 3 )] + ( 10 ), Ru(η 5 -C 5 H 5 ){C(NH 2 ) C CH 2 }(CO)(PH 3 ) ( 11 ), and Ru(η 5 -C 5 H 5 ){C(CH CH 2 ) NH}(CO)(PH 3 ) ( 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.