In the title compound, C25H29FO4, each cyclo-hexenone ring has an envelope conformation with the dimethyl-substituted atom as the flap. The hy-droxy and carbonyl groups form two intra-molecular O-H⋯O hydrogen bonds, as is typical for xanthene derivatives. In the crystal, very weak C-H⋯O hydrogen bonds link mol-ecules into dimers.

In the title compound, C(21)H(21)NO(6), each of the cyclo-hexenone rings adopts a half-chair conformation. Each of the pairs of hy-droxy and carbonyl O atoms are oriented to allow for the formation of intra-molecular O-H⋯O hydrogen bonds, which are typical of xanthene derivatives.

In the title compound, C(28)H(32)N(4)O(3), the dihedral angle between the planes of the xanthene ring system and the spiro-lactam ring is 85.99 (3)°. Mol-ecules are linked by inter-molecular O-H⋯O and N-H⋯O hydrogen-bonding inter-actions.

The title compound, C(12)H(12)N(4), was synthesized by the reaction of hydrazine hydrate and 9-methyl-3,4,6,7-tetra-hydro-2H-xanthene-1,8(5H,9H)-dione in ethanol. In the crystal, the mol-ecule lies across an inversion centre. The pyridazine rings are coplanar and the C(6) rings adopt envelope conformations.

A simple and efficient procedure for the synthesis of 14-aryl-14H-dibenzo[a,j ]xanthene derivatives through one-pot condensation of 2-naphthol with aryl aldehydes in the presence of niobium pentachloride is described. The reactions were carried out using 25 mole % of NbCl5, at ambient temperature, and in acceptable reaction times, affording excellent yields of the products. c © 2014 Institute o...

In the title compound, C(38)H(42)N(4)O(4)·C(2)H(6)O, prepared via a spiro-lactam ring-formation reaction in a rhodamine dye, the xanthene ring system is approximately planar (r.m.s. deviation = 0.0014Å) and subtends dihedral angles of 88.10 (3) and 86.92 (4)° with the spiro-lactam (r.m.s. deviations = 0.0012 Å) and benzene rings, respectively. The crystal structure consists of chains parallel t...

In the title compound, C(21)H(18)O(3), the xanthene system and the meth-oxy-phenyl ring are practically orthogonal with a dihedral angle between their mean planes of 89.27 (3)°. The meth-oxy group attached to the phenyl ring makes a C-O-C-C torsion angle of 11.56 (18)°. In the crystal, mol-ecules are linked by C-H⋯O inter-actions into chains along [010]. Weak C-H⋯π inter-actions also occur.

In the title compound, C(22)H(24)O(5), each of the cyclo-hexenone rings adopts a half-chair conformation. The hy-droxy and carbonyl O atoms face each other and are orientated to allow for the formation of the two intra-molecular O-H⋯O hydrogen bonds which are typical of xanthene derivatives. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules into layers parallel to the ab...

An efficient route is reported to 5- and 6-carboxy-X-rhodamines (compounds 1 and 2) that contain multiple n-propylene or gamma,gamma-dimethylpropylene groups bridging terminal nitrogen atoms and the central xanthene core. Gram quantities of these dyes are synthesized from inexpensive starting materials. The isolated products are activated by selective transformation of the carboxylic acid group...

Synthesis, characterization and reactivity studies of a hetero-dicopper complex, particularly towards oxygen reduction are presented. A bischlorido copper(II) trishistidine-type coordination unit is positioned directly above copper porphyrin unit. The close distance between the two fragments secured by rigid xanthene backbone. Surprisingly, dinuclear complex not active unlike earlier published ...