Vincenzo Passarelli, Ramón Macías, Luis A. Oro, Jonathan Bould
The metallathiaboranes [8,8-(dppe)-nido-8,7-NiSB9H11] [1, dppe = bis(diphenylphosphanyl)ethane], [7-Et-8,8-(dppe)-nido-8,7-NiSB9H10] (2), [9-Et-8,8-(dppe)-nido-8,7-NiSB9H10] (3) and [2,2-(dppe)-closo-2,1-NiSB8H8] (4) are isolated from the reactions between Cs[arachno-SB9H12], Li[BHEt3] and [NiCl2(dppe)] at low temperature in yields of 30, 1, 0.1 and <1 %, respectively. The arachno-nickellathiadecaborane [6,6-(dppe)-arachno-6,9-NiSB8H10] (5) is isolated from the reaction between [(N,N,N′,N′-tetramethylnaphthalene-1,8-diamine)H][SB8H11], Li[BHEt3] and [NiCl2(dppe)] at low temperature (75 % yield). Compound 1 reversibly takes up NH3 in solution, and the characterization of the resulting compound is discussed. Compound 5 shows no interactions with ammonia but does reversibly take up CO to give [6,6,6-(CO)(dppe)-arachno-6,9-NiSB8H10] (7). The CO molecule is very weakly bound and is lost readily even in the solid state. Similarly to 1, the isonido-iridathiaundecaboranes [(L)2-H-isonido-IrSB9H9] (L = PMe3 and PMe2Ph) also reversibly takes up NH3 to afford [8,8,8-(PMe3)2(NH3)-nido-8,7-IrSB9H10]·NH3 (8) and [8,8,8-(PMe2Ph)2(NH3)-nido-8,7-IrSB9H10] (9) quantitatively. The ferrathiaborane compound [1,1,3-(dppe)2-1,2-closo-FeSB9H9] (11) was isolated in trace yield when [FeCl2(dppe)] was used as the starting metal complex. When appropriate, the compounds were characterized by single-crystal X-ray diffraction studies, multielement NMR spectroscopy together with DFT gauge including atomic orbitals (GIAO) chemical-shielding calculations, IR spectroscopy and elemental analysis.The interactions of new metallathiaboranes with the small molecules NH3 and CO are investigated. The reversible uptake of the molecules can be modified by changing the metal, the thiaborane fragment or the ligand sphere. This chemistry represents the first stage in our design of new systems for the activation of small molecules using earth-abundant metals.