Design of chela-shaped clathrate hosts, inclusion properties and its application to selective isolation of effective component from volatile oil of Chinese herb Xixin

Two new clathrate hosts characteristic of a chela-shaped molecular back bon e, trans-1,2-biphenyl-1,2-acenaphthendiol 1 and cis-1,2-bi-1'-naphthyl-1,2- acenaphthenediol 2 were designed. 1 and 2 can form coordinatoclathrate with various small organic compounds and these inclusion compounds were confirm ed by means of IR and powder XRD. The host-guest molar ratios were determin ed by H-1 NMR and the following results were found: 1.DMF(1 : 2), 1.DMSO(1 : 2), 1.THF(1 : 2), 1.1,4-dioxane (1 : 1), 1.pyridine(1 : 1), 2.DMF(1 : 1) and 2.DMSO(1 : 1). The single crystal structures of new inclusion compounds were determined by X-ray diffraction analysis. The crystal of host(1).DMF belongs to space group Pnaa, a = 0.9377(1), b = 1.4351(1), c = 4.0463(3) nm and 1.DMSO has space group Pbcn, a = 1.6278(1), b = 1.0751(1), c = 1.4980( 1) nm and host(2).DMF belongs to P2(1)/n, a = 0.9796(1), b = 1.2377(1), c = 2.2344(3) nm; beta = 93.02(1)degrees. The crystal analysis of freehost (1) showed space group P (1) over bar, and a = 1.046(1), b = 1.1213(1), c = 1. 5496(1) nm, alpha = 81.74(1)degrees, beta = 75.78(1)degrees, gamma = 89.00( 1)degrees. The effect of rigidity and flexibility of host molecules on incl usion properties were discussed. The selective isolation of the effective c omponent (1,2-dimethoxy-4-2'-propenylbenzene) from the volatile oil of Chin ese herb Xixin by host (1) was carried out.