Synthesis and Crystal Structure of Two iso-closo 11-Vertex p-Bromobenzoate Ruthenoborane Clusters: [(PPh3)(p-BrC6H4CO2)2RuB10H8] and [(PPh3)2Ru(p-BrC6H4CO2)-(PPh3)RuB10H9]

The title clusters [(PPh3)(p‐BrC6H4CO2)2RuB10H8] (1) and [(PPh3)2Ru(PPh3)(p‐BrC6H4CO2)RuB10H9] (2) have been prepared and characterized by elemental analysis, FT‐IR, 1H, 13C NMR spectra and single‐crystal X‐ray diffraction analysis. The clusters crystallize in monoclinic system, space group C2/c, with a=2.569(4) nm, b=1.546(2) nm, c=1.927(3) nm, β=95.11(2)°, Z=8, V=7.622(21) nm3, Dc=1.533 Mg/m3, F(000)=3472, S=1.009, R=0.0418, wR=0.0775 and triclinic system, space group P‐1, with a=1.3142(3) nm, b=1.3761(3) nm, c=1.8503(4) nm, α=90.445(4)°, β=105.950(4)°, (=108.980(4)°, Z=2, V=3.0251(12) nm3, Dc=1.434 Mg/m3, F(000)=1316, S=1.007, R=0.0464, wR=0.1175, respectively for 1 and 2. In the structures, both of the clusters are based on a closo‐type C2v 1:2:4:2:2 RuB10 stack with the metal occupying the unique six‐connected apical position. In cluster 1, the metal center has three exo‐polyhedral ligands:one triphenylphosphine and two dative oxygen atoms of p‐bromobenzoates. The other oxygen atoms of two p‐bromobenzoate are additionally bonded to B(2) and B(3) atoms respectively, resulting in two exo‐cyclic five‐membered Ru‐O‐C‐O‐B rings and engendering a symmetrical conformation. The cluster 2 is a bimetallic species in which the second ruthenium is bound to the {RuB10} center via one Ru–Ru bond and two {RuHµB} bridges resulting in one closo distorted exo‐polyhedral Ru(1)‐ Ru(2)‐B(3)‐B(6) tetrahedron.