Synthesis, Characterization and Structural Determination of Ferrocene Derivatives Linked with Benzo[b]pyrans ——2-Amino-7,7-dimethyl-4-ferrocenyl-5-oxo-5,6, 7,8-tetrohydro-4H-chromene-3-carbonitrile

The title compound (C22H22N2O2Fe·CH3OH) was synthesized via a one-pot proce- dure from ferrocenylaldehyde, malononitrile and 5,5-dimethyl-1,3-cyclohexanedione using room temperature ionic liquid and pyridine as the catalysts, and characterized by elemental analysis, IR and 1H NMR. The structure was determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic system, space group P21/n, with a = 9.7085(15), b = 22.951(4), c = 9.987(2) A, β = 112.494(3)°, V = 2055.9(6) A3, Z = 4, Mr = 402.28, Dc = 1.403 g/cm3, μ = 0.759 mm-1, F(000) = 868, the final R = 0.0536 and wR = 0.1449 for 4202 observed reflections with I > 2σ(I). The supramolecular single-helix chain of the title compound is formed by linking the building units with the hydrogen bond between N1 and N2. The adjacent chains are connected to a 2D layer by the hydrogen bond between N1 and O1. The adjacent layers are further linked by van der waals’ force. The CH3OH molecule is trapped in the interlayer.