Crystal and molecular structure of 1-methyl-4-(2-(3,4-dimethoxyphenyl)vinyl) pyridinium 4-tolysulfonate dihydrate C16H18NO2+ center dot C7H7SO3- center dot 2H(2)O

The crystal structure of the title compound C16H18NO2+ . C7H7SO3- . 2H(2)O, (C23H29NSO7, M-r=463.53) has been determined by single-crystal X-ray diffr action analysis. The crystal belongs to the monoclinic system with space gr oup P2(1)/n, a=8.101(1), b=8.958(2), c-33.281(5)Angstrom, beta =94.910(1)de grees V=2406.3(7)Angstrom (3), Z=4, D-c=1.279g/cm(3), mu =0.176mm(-1), F(00 0)=984, final R=0.0409, and Rw=0.0860 for 4401 independent reflections. The result shows that in the crystal structure of the title compound the plana r cations have two configurations with equal occupation ratio and are antip arally packed throughn pi . . . pi interactions. Similar packing energies i n A and B are probably the main factor that leads to the disorder structure .