Crystal and molecular structure of the rutheniumcarbene-tetraborohydrate complex [Ru(BH4)(LAr)(PPh3)2]; (LAr=CN(C6H4Me-4)CH2CH2NC6H3Me-4)

The structure of the title compound has been determined by single crystal X-ray diffraction analysis:P2₁/c,M _r=889.9,a=15.940(1),b=23.357(2),c=18.767(2) Å,=132.62(1)°,V _c=5141.6 ų,Z=4,D _x=1.150 mg m^–3,F(000)=1848; finalR _f=0.074 (R _w=0.085). The BH ₄ ^– ligand in the complex is bidentate. A comparative study indicates that the lengths of the Ru-carbene carbon bond and other bonds to the Ru atom are determined by a combination of several factors, and not just by a purely - or -bonding interaction.