Abstract: Two Novel 3-diferrocenyl dihydropyrazole derivatives were synthesized from corresponding α,β-unsaturated ketones. The structures of these compounds were characterized by IR, 1H NMR spectra and X-ray single crystal diffraction. The crystal structure of compound 3a belongs to the orthorhombic,space group P2(1)2(1)2(1) with the lattice parameters a = 0.59466(12) nm，b = 1.9402(8) nm，c = 3.1274(6) nm，α = 90.00°，β = 90.00°，γ = 90.00°，Z = 4，F(000) = 1280，DC = 1.442 g/cm3，μ = 0.817 nm-1. Its crystal structure showed that chain-like one-dimentional structure was formed along a axis by the intermolecular hydrogen bonds.The compound 3b belongs to the monoclinic, space group P2(1)/c,and its lattice parameters are as follows: a = 1.3087(3) nm，b = 0.9844(2) nm，c = 1.7752(4) nm，α = 90.00°，β = 99.42(3)°，γ = 90.00°，Z ＝ 4，F(000) = 1112.0，DC = 1.617 g/cm3，μ = 2.558 nm-1. The intermolecular hydrogen bonds between the sulfonyl oxygen and nonsubstituted cyclopentadienyl (Cp) hydrogen and bromobenzene hydrogen led to the formation of stable supermolecular structure of one 3b with three otherwise 3b molecules.

Key words: Ferrocenyl derivatives, Dihydropyrazole, Intermolecular hydrogen bond, Molecular assembly