Polyhedral Ruthenaborane Chemistry Preparation, Molecular Structure, and N.M.R. Properties of the Mixed‐Ligand Eleven‐Vertex isocloso ‐Type Compound [1,1‐(PMe 3 ) (PPh 3 )‐ closo ‐1‐RuB 10 H 8 ‐2,3‐(OEt) 2 ]

Treatment of [1,1‐(PPh 3 ) 2 ‐ closo ‐1‐RuB 10 H 8 ‐2, 3‐(OEt) 2 ] 1 ) 1 with the more basic ligand PMe 3 readily results in the displacement of PPh 3 to form the hitherto unreported mixed ligand compound [1,1‐(PMe 3 ) (PPh 3 )‐ closo ‐1‐RuB 10 H 8 ‐2, 3‐(OEt) 2 ] 2 , which is characterized by singlecrystal X‐ray diffraction analysis. Crystals are monoclinic, space group P2 1 , with a = 1059.2(2), b = 1291.5(2), c = 1187.6(2) pm, β = 91.56(1)°, Z = 4; the final R factor is 0.0198 for 3303 observed reflections [I>2.0 s̀(I)]. Compound 2 is also characterized by detailed multielement, multiple resonance, and multidimensional n.m.r. spectroscopy ( 1 H, 1 H‐{ 11 B}, [ 1 H– 1 H]{ 11 B}‐COSY, 11 B, 11 B‐{ 1 H}, and 31 P).