Could X-ray analysis explain for the differing antimicrobial and antioxidant activity of two 2-arylamino-3-nitro-coumarins?

Abstract

X-Ray analyses of 4-(naphthalen-1-ylamino)- 3-nitro-chromen-2-one and 3-nitro-4-phenylamino-chromen- 2-one showed that thementioned compounds crystallize in the space groups P1- (triclinic crystal system; unit cell parameters: a = 8.087(2) Å, b = 9.241(3) Å, c = 10.911(3) Å, α = 93.77(3)°, β = 102.51(3)°, γ = 106.44(2)°, V= 756.4(4) Å 3 and Z = 2) and P2 1 2 1 2 1 (orthorhombic crystal system; unit cell parameters: a = 4.9274(9) Å, b = 14.725(3) Å, c = 17.866(4) Å, α = β = γ = 90°, V = 1296.3(5)Å 3 and Z = 4), respectively. The analyses of crystal structures and gas phase conformations, inferred from single X-ray crystallographic and molecular modeling experiments, respectively, showed that the changes in p delocalization of the farmacoactive formal 3-amino-2-nitro-acrylic acid derivatives might explain the observed significant difference of the antimicrobial and antioxidant activities and spectral properties of two 4-arylamino-3-nitro-coumarin derivatives. © Springer Science+Business Media, LLC 2010.