Metal‐Rich Metallaboranes: Structures and Geometries of Heterometallic µ9‐Boride Clusters. Issue 22 (30th May 2018) - Bhattacharyya, Moulika
Abstract : Treatment of a dirhodium analogue of pentaborane(9), [(Cp*Rh)2 B3 H7 ] ( nido ‐1 ; Cp* = η 5 ‐C5 Me5 ), with [Fe2 (CO)9 ] at room temperature led to the formation of [(Cp*Rh)2 Fe(CO)3 (µ‐CO)B3 H2 Cl] (2 ) and the metal‐rich metallaborane [(Cp*Rh)2 Fe(CO)3 Fe(CO)2 (µ‐CO)2 B2 H2 ] (3 ). When the same reaction was carried out at moderate temperature, two metal‐rich metallaboranes, [(Cp*Rh)3 Fe(CO)2 (µ3 ‐CO)2 B2 HX]4 (X = H) and5 (X = Cl), and a heterometallic µ9 ‐boride cluster, [(Cp*Rh)3 (RhCO)3 Fe(CO)3 (µ‐CO)3 B3 H2 ] (6 ), were obtained. Compounds4 and5 can be viewed as cubane clusters with 62 cluster valence electrons (cves) and five metal–metal bonds. In another reaction, the treatment of nido ‐1 with [Mn2 (CO)10 ] yielded the heterometallic µ9 ‐boride cluster [(Cp*Rh)3 Rh(CO)2 {Mn(CO)3 }2 B4 H3 ] (7 ). The cluster cores of both6 and7 are comprised of tricapped trigonal prisms containing a µ9 ‐B atom bonded to seven/six metals and two/three boron atoms, respectively. All the new compounds have been characterized by mass spectrometry, IR, 1 H, 11 B{ 1 H}, and 13 C{ 1 H} NMR spectroscopy, and X‐ray crystallographic analysis. Abstract : The cluster expansion reaction of a dirhodium analogue of pentaborane(9) with metal carbonyl complexes produces metal‐rich metallaboranes and µ9 ‐boride clusters.