Complexation of 6-(4 '-(toluidinyl)naphthalene-2-sulfonate by beta-cyclodextrin and linked beta-cyclodextrin dimers

The complexation of 6-(4'-(toluidinyl)naphthalene-2-sulfonate, TNS-, by beta-cyclodextrin (beta CD) and. five linked beta CD-dimers is characterized by UV-Vis,. fluorescence and H-1 NMR spectroscopy. In aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm(-3) and 298.2 K, TNS- forms host - guest complexes with bCD of stoichiometry beta CD.TNS (-) {K-1 = [bCD.TNS-]/([ bCD][ TNS-]) = 3300 dm(3) mol(-1)} and beta CD2,TNS-{K2 = [beta CD2.TNS-]/([beta CD][beta CD.TNS-]) = 11 dm(3) mol(-1)} as shown by. uorescence studies. For N,N-bis((2(A)dextrin)- S,3(A)S)- 3(A)- deoxy-3(A)- bcyclodextrin) succinamide, 33 beta CD(2)su, N-((2(A)S,3(A)S)-3(A)-deoxy-3(A)-beta-cyclodextrin) N0-(6(A)-deoxy-6(A)-beta-cyclodextrin) urea, 36 beta CD(2)su, N,N-bis(6(A)-deoxy-6(A)-beta-cyclodextrin) succinamide, 66 beta CD(2)su, N-((2(A)S,3(A)S)-3(A)-deoxy-3(A)-beta-cyclodextrin)- N'-(6(A)-deoxy-6(A)-beta-cyclodextrin) urea, 36 beta CD(2)ur, and N, N- bis( 6(A)-deoxy- 6(A)-beta-cyclodextrin) urea, 66 beta CD(2)ur, the analogous K1 = 9600, 8700, 12 500, 9800, and 38 000 dm(3)mol(-1), respectively. H-1 NMR ROESY studies provide evidence for variation of the mode of complexation of the TNS- guest as the host is changed. The factors a. ecting complexation are discussed and the synthesis of the new linked beta CD-dimer 36 beta CD(2)su is reported.