2-[(5-Chloro-2-hy-droxy-benzyl-idene)amino]-3',6'-bis-(diethyl-amino)-spiro-[isoindoline-1,9'-xanthen]-3-one.

The title compound, C(35)H(35)ClN(4)O(3), resulted from a spiro-lactam ring closure of rhodamine B dye. The xanthene ring system is approximately planar [r.m.s. deviation = 0.050 (9) Šfor the xanthene ring]. The dihedral angles formed by the spiro-lactam and 5-chloro-2-hy-droxy-benzene rings with the xanthene ring system are 87.9 (7) and 79.1 (7)°, respectively.