Refinement of the crystal structure of 1,10-phenanthrolinium tetrachloro- (1,10-phenanthroline)ferrate(III), (C12H9N2)[FeCl4(C12H8N2)

Abstract

C24H17Cl4FeN4, triclinic, P1 (no. 2), a = 8.694(3) A, b = 11.306(4) A, c = 12.802(4) A, 4 = 111.08(2)°, 3 = 96.22(2)°, 2 = 93.68(3)°, V = 1160.0 A, Z = 2, Rgt(F) = 0.027, wRref(F) = 0.070, T = 293 K. Source of material A solution of iron(III) chloride hexahydrate (0.273 g, 1 mmol) in hot water (20 ml) was filtered and an aqueous solution (2 ml) of 1,10-phenanthrolinium chloride monohydrate (0.474 g, 2 mmol) was added. The mixture was stirred at 333 K for 3 h. The deep orange solutionwas filtered and the filtratewas dried under reduced pressure. The deep orange powder was dissolved in a small amount of acetonitrile and left at room temperature for several days to yield orange single crystals (yield 0.44 g, 78.6 %, m.p. 541-543 K). Discussion Metal complexes of ligands containing diimine structures such as 1,10-phenanthroline and their derivatives have gained importance because of their versatile roles as building blocks for the synthesis ofmetallo-dendrimers,molecular scaffolding for supramolecular assemblies, analytical chemistry, catalysis, electrochemical and ring-opening metathesis polymerization and biochemistry [1-4]. The crystal structure of the title compound has been determined previously [5] with a reliability factorRgt(F) = 0.077. The present redetermination converges with lower reliability factors and confirms the previous study [5]. In addition, phenanthrolinium tetrachloro-phenanthroline-iron(III) sesquihydrate has also been subject to single-crystal X-ray diffraction [6]. We report here the X-ray crystal structure analysis of the title compound using more accurate intensity data. Bond lengths and angles can be regarded as normal (Cambridge Structural Database, version November 2005 [7]). The asymmetric unit consists of one crystallographically independent anionic hexacoordinated complex [Fe(phen)Cl4] and one protonated 1,10-phenanthroline counter ion. In the anionic part, the iron atom has a distorted octahedral environment by two nitrogen atoms from a phenanthroline ligand and four chlorine atoms. The different Fe—Cl bond distances are 2.3123(7) A and 2.3266(10) A for the equatorial sites and 2.3578(8)A and 2.4069(8)A for the axial positions. The longer of the Fe—Cl equatorial bond distances are balanced by slightly shorter Fe—N bonds, 2.195(1) A and 2.207(2) A on the opposite sides.Within the plane, each [Fe(phen)Cl4] anion binds to three organic donors through the close N(phen)···Cl and C(phen)···Cl contacts (N3···Cl1 of 3.296(2) A and C13···Cl1 of 3.387(2) A, where the N···Cl and C···Cl van der Waals distances are 3.30A and 3.45A, respectively andN(phen)–H···Cl (H3A···Cl4 of 2.608(3)A, N3···Cl3 of 3.247(2)A andN3–H3A···Cl3 angle of 138.15(3)°) and C(phen)–H···Cl hydrogen bonds. Z. Kristallogr. NCS 223 (2008) 41-42 / DOI 10.1524/ncrs.2008.0020 41 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: orange prism, size 0.20 × 0.35 × 0.40 mm Wavelength: Mo K4 radiation (0.71073 A) *: 11.32 cm−1 Diffractometer, scan mode: Stoe IPDS II, ./6 2%max: 55.92° N(hkl)measured, N(hkl)unique: 8633, 5583 Criterion for Iobs, N(hkl)gt: Iobs > 2 #(Iobs), 4582 N(param)refined: 366 Programs: SHELXS-97 [8], SHELXL-97 [9], X-STEP32 [10] Table 1. Data collection and handling.