Crystal structure of trans-dichloro-1,3-propanediamine-bis[(2-methoxyethyl) diphenylphosphine]ruthenium(II), RuCl2(C3H10N2)(C15H17OP)2

Abstract

C 33 H 44 Cl 2 N 2 O 2 P 2 Ru, monoclinic, P12 1 /c1 (no. 14), a = 13.278 (1) Source of materialAll the reactions were performed using Schlenk-type flask under argon and standard high vacuum-line techniques. Solvents were of analytical grade and distilled under argon. The title compound was synthesized by treating RuCl 2(h 2 -Ph2PCH2CH2OCH3)2 complex with slightly excess 1.3-propanediamine ligand in dichloromethane as described previously [1]. The crystals were grown by slow diffusion of diethyl ether into a solution of the complex in dichloromethane. They were re-crystallized from these two solutions. The desired complex was characterized by NMR, IR, and FAB-mass spectroscopy in addition to the elemental analysis [1,2]. DiscussionNowadays, due to economical and environmental inciting, increasing attention is dedicated to catalysts and reagents [3,4]. An attractive strategy to consist in the homogenous catalysts by using dichloro(phosphine)diamineruthenium complexes in field of hydrogenation has been recently constructed [3][4][5][6]. The two hemilabile bidentate ether-phosphine ligands were coordinated the ruthenium(II) center atom via phosphor and oxygen atoms. The (ether) oxygen atom can easily be displaced by an incoming substrate such as diamine [1,2,7,8]. Thus, ether-phosphines are capable of making available and protecting vacant coordination sites which lead to an improvement in both stability and catalytic activity of the organometallic species [7,8]. The title complex is crystallized as free solvated trans-dichlorocis-phosphine isomers with approximate C 2 symmetry. The ruthenium atom is coordinated two chlorine species in trans form, one diamine co-ligand via the nitrogen atoms and two (2-methoxyethyl)(diphenyl)-phosphine ligands via the phosphorus atoms in cis forms. The complex exhibits mostly regular octahedron geometry around the ruthenium center atom with two RuN distances of 2.1993 Å and 2.1932 Å, two RuCl distances of 2.4177 Å and 2.4244 Å and two RuP distances equal 2.2963 Å and 2.2910 Å. The diamine and ether-phosphine ligands are practically planar. (Deviations from the least-squares planes do not exceed 0.1 Å.) The coordination angle of the diamine chelate ring results in distinctly NRuN angles of 84.71°departs from ideal value by up to approximately 5.3 Å, due to the six-membered ring chelating nature of 1,3-propanediamine ligand, while the PRuP angle is equal 91.17°. The dichloro ligands are bent away from their axial positions toward the diamine ligand forming ClRuCl angles of 165.61°, resonating to the steric effect of the phenyls in the etherphosphine ligands. In the crystal structure there is a number of RuCl···H2N contacts smaller than 3.0 Å at the same molecule, indicating the presence of unconventional intra-hydrogen bonds.