Synthesis and Crystal Structure of 10-(4-nitrophenymethylidyne)-9,10-dihydrofluorene

A novel compound of 10-(4-nitrophenymethylidyne)-9,10- dihydrofluorene (C20H13NO2, Mr=299.31) was synthesized via Knoevenagel reaction in the presence of sodium hydroxide under solvent-free condition. The advantages of this procedure were mild reaction conditions, simple protocol, and high yield (93%). Its structure was determined IR, 1H NMR, MS, elemental analysis and X-ray diffraction. The crystal of the new compound is Orthorhombic, space group Pbca with a = 11.6269(10), b = 7.6792(6), c = 33.862(3) Å, = 90, = 90, = 90o, V= 3023.4(4) Å3, Z=8, Dc=1.315g/cm3, μ=0.085 mm-1, F(000)=1248, R=0.0589 and wR = 0.1284 for 2751 observed reflection with I>;2σ(I). π-π stacking interactions contribute to the stability of the structure.