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Treatment of a dirhodium analogue of pentaborane(9), [(Cp*Rh)2B3H7] (nido‐1; Cp* = η5‐C5Me5), with [Fe2(CO)9] at room temperature led to the formation of [(Cp*Rh)2Fe(CO)3(µ‐CO)B3H2Cl] (2) and the metal‐rich metallaborane [(Cp*Rh)2Fe(CO)3Fe(CO)2(µ‐CO)2B2H2] (3). When the same reaction was carried out at moderate temperature, two metal‐rich metallaboranes, [(Cp*Rh)3Fe(CO)2(µ3‐CO)2B2HX] 4 (X = H) and 5 (X = Cl), and a heterometallic µ9‐boride cluster, [(Cp*Rh)3(RhCO)3Fe(CO)3(µ‐CO)3B3H2] (6), were obtained. Compounds 4 and 5 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)3Rh(CO)2{Mn(CO)3}2B4H3] (7). The cluster cores of both 6 and 7 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, 1H, 11B{1H}, and 13C{1H} NMR spectroscopy, and X‐ray crystallographic analysis. [ABSTRACT FROM AUTHOR]

A combined experimental and quantum-chemical study of a series of homometallic metallaheteroboranes [(Cp*M)2-E6B2H2] (M = Rh or RuH; E = S or Se; Cp* = η5-C5Me5), which are analogues of 1,3-bishomocubane, is reported. The thermolysis of nido-[(Cp*Rh)2B3H7] (1) in the presence of S or Se powder in toluene yielded bishomocubane clusters [(Cp*Rh)2-(μ-E)2(μ3-E)4B2H2], (3: E = S; 4: E = Se). In a similar fashion, the treatment of nido-[(Cp*RuH)2B3H7] (2) with S or Se powder in p-xylene yielded [(Cp*Ru)2(μ-E)2(μ3-E)4B2H2] (5: E = S; 6: E = Se) and [(Cp*Ru)2(μ3-Se)(μ4-Se)B3H5] (7). One of the noteworthy features of 3-6 is the presence of an electronprecise trichalcogenoborato ligand. All of the compounds have been characterized by mass spectrometry; IR spectroscopy; and 1H, 11B, and 13C NMR spectroscopy. The structures of 3, 4, 6, and 7 were established unequivocally by Xray crystallographic analysis. Quantum-chemical calculations by DFT methods for 3, 4, and 6 showed reasonable agreement with the experimentally observed structural parameters. The large HOMO-LUMO gaps are consistent with the high stabilities of these complexes. [ABSTRACT FROM AUTHOR]

A combined experimental and quantum-chemical study of a series of homometallic metallaheteroboranes [(Cp*M)2E6B2H2] (M = Rh or RuH; E = S or Se; Cp* = η5-C5Me5), which are analogues of 1,3-bishomocubane, is reported. The thermolysis of nido-[(Cp*Rh)2B3H7] ( 1) in the presence of S or Se powder in toluene yielded bishomocubane clusters [(Cp*Rh)2(μ-E)2(μ3-E)4B2H2], ( 3: E = S; 4: E = Se). In a similar fashion, the treatment of nido-[(Cp*RuH)2B3H7] ( 2) with S or Se powder in p-xylene yielded [(Cp*Ru)2(μ-E)2(μ3-E)4B2H2] ( 5: E = S; 6: E = Se) and [(Cp*Ru)2(μ3-Se)(μ4-Se)B3H5] ( 7). One of the noteworthy features of 3- 6 is the presence of an electron-precise trichalcogenoborato ligand. All of the compounds have been characterized by mass spectrometry; IR spectroscopy; and 1H, 11B, and 13C NMR spectroscopy. The structures of 3, 4, 6, and 7 were established unequivocally by X-ray crystallographic analysis. Quantum-chemical calculations by DFT methods for 3, 4, and 6 showed reasonable agreement with the experimentally observed structural parameters. The large HOMO-LUMO gaps are consistent with the high stabilities of these complexes. [ABSTRACT FROM AUTHOR]