156761-95-4Relevant academic research and scientific papers
Nine-vertex Polyhedral Iridamonocarbaborane Chemistry. Products of Thermolysis of and Emerging Alternative Cluster-geometry Patterns
Stibr, Bohumil,Kennedy, John D.,Drdakova, Eva,Thornton-Pett, Mark
, p. 229 - 236 (1994)
Thermolysis of 1 at 250 deg C resulted in isomerisation to give orange air-stable 2 and its 6-(PPh3) isomer 3 as the major products.The compounds were characterised by NMR spectroscopy and single-crystal X-ray diffraction analysis on 1 and 3.The CH2Cl2 disolvate of 1 is monoclinic, space group P21/n, with a = 1394.33(10), b = 1276.81(13), c = 2393.5(2) pm, β = 94.163(9) deg, and Z = 4, and the structure was refined to R(Rg) = 0.0351(0.0384) for 5991 reflections with I > 2.0?(I).The CH2Cl2 monosolvate of 3 is triclinic, space group P, with a = 1150.39(11), b = 1177.08(13), c = 1498.3(2) pm, α = 88.192(9), β = 89.506(8), γ = 80.720(9) deg, and Z = 2, and the structure was refined to R(Rg) = 0.0299(0.0311) for 5864 reflections with I > 2.0?(I).The nine-vertex cluster structures of 1 and 3 have quadrilateral open faces (B-B ca. 220 pm) and therefore 'isonido' geometries although of formal closo constitution.The cluster opening is briefly discussed in the context of a nine-vertex closo-isonido-isocloso structural continuum, in the context of other contemporaneously recognised structural continua in twelve-, eleven-, ten- and eight-vertex boron cluster chemistry, and thence in the context of emerging general structural patterns that interrelate the isocloso, isonido and isoarachno cluster geometries.
