CONFORMATION OF A FLUOROCHROME FROM ANILINE BLUE

The solid-state conformation of the fluorochrome sodium is(benzene-4,1 -diy])bis(imino)-bisbenzenesulfonate has been defined by single-crysta l X-ray crystallography. Monoclinic crystals belong to the space group C 2/c with a 11.732(1), b 6.185(1), c 37.179(3) Angstrom, beta 94.40( 1)degrees and Z 8. The structure was refined to a final R 0.042 for al l 2271 unique terms. In the crystal six oxygen atoms form an octahedra l grouping around the sodium ion and these octahedra are linked into l ayers sandwiched between the layers of organic anions which adopt an e xtended conformation. The n.m.r. spectra indicate that in solution the fluorochrome is flexible and averages to an extended structure that m aintains symmetry about its longitudinal and carbonyl axes. Chemical s hifts have been measured in water, deuterium oxide and (D-6)dimethyl s ulfoxide.