[(2-{[3',6'-Bis(ethyl-amino)-2',7'-dimethyl-3-oxospiro-[1H-isoindole-1,9'-9H-xanthen]-2-yl}eth-yl)amino-meth-yl]phenol.

The title compound, C(35)H(38)N(4)O(3), was prepared as a spiro-lactam ring formation of rhodamine dye for comparison with a ring-opened form. The xanthene ring system is approximately planar. The dihedral angles formed by the spiro-lactam and phenol rings with the xanthene ring system are 85.7 and 109.4°, respectively. Each of the mol-ecules in the crystal structure contains one intra-molecular O-H⋯N hydrogen bond, and they form inter-molecular N-H⋯O hydrogen-bonded chains along the [100] direction. Weak inter-molecular C-H⋯O hydrogen-bonding contacts connect the infinite chains via crystallographic inversion centres to form a two-dimensional network.