Benzyltributylammonium 6,7-dihydroxynaphthalene-2-sulfonate

The title molecular salt, C19H34N+·C10H7O5S−, is a charge-control agent used for toners in electrophotography. There are two formula units in the asymmetric unit. Both anions form inversion dimers connected by pairs of O-H...O hydrogen bonds between the -OH group of one anion and a sulfonic O atom of the neighboring one. The two dimers A and B are characterized by a step between the least-squares planes of the naphthalene atoms of 0.85 and 2.30 Å. Further O-H...O bonds link the dimers into a two-dimensional network propagating in (110) such that dimer A is hydrogen-bonded to four B units and vice versa. One of the tert-butyl chains in one of the cations is disordered over two sets of sites in a 0.56:0.44 ratio.