Synthesis and crystal structure determination of iridium(III) acetylacetonate and its Br- and I-substituted analogs

gamma-Halogen-substituted iridium(III) acetylacetonates of general formula Ir(acacX)(3), where acacX = CH3-CO-CX-CO-CH3, X = Br, I, were synthesized. The compounds are characterized by melting points and chemical analysis dat a for C, H, Br, and I. An X-ray diffraction analysis was performed for irid ium(III) acetylacetonate and its gamma-substituted analogs, crystal data we re obtained and crystal structures were determined. The crystals are monocl inic; the structures are molecular. Crystal data: Ir(acac)(3)IrO6C15H21, a = 13.900(2), b = 16440(3), c = 7.494(2) Angstrom, gamma = 98.63(2)degrees, V = 1693.2 Angstrom(3), space group kP2(1)/b, Z = 4, d(calc) = 1.92 g/cm(3) , sin Elf,, = 0.703, F-hkl = 2841, R = 0.044 Ir(acacBr)(3)-IrBr3O6C15H18, a = 12.794(2), b = 15.753(2), c = 9.990(2) Angstrom, beta = 105.76(2)degrees , V = 1937.6 Angstrom(3), space group P2(1)/n, Z = 4, d(calc) = 2.49 g/cm(3 ), sin theta/lambda(max) = 0.702, F-hkl = 1748, R = 0.048. Ir(acacI)(3)-IrI 3O6C15H18, a = 12.855(2), b = 10.136(2), c = 16.338(3) Angstrom, beta = 104 .6(2)degrees, V = 2059.8 Angstrom(3), space group P2(1)/n, Z = 4 d(calc) = 2.79 g/cm(3), theta(max) = 25 degrees, F-hkl = 2817, R = 0.032. The Ir...Ir distances were estimated to be >7.49 Angstrom far Ir(acac)(3) and >8.10 An gstrom for Ir(acacBr)(3) and Ir(acacI)(3). If the estimate is limited to 10 Angstrom, the intermolecular coordination number (ICN) in the structures i s 10.