In the title mol-ecule, C(35)H(22)BrNO(2), the four-membered ring of the β-lactam unit is nearly planar [maximum deviation = 0.003 (3) Å] and makes dihedral angles of 87.07 (15), 59.80 (16) and 20.81 (19)°, respectively, with the xanthene system, the anthracene system and the bromo-substituted benzene ring. The mol-ecular conformation is stabilized by weak intra-molecular C-H⋯O and C-H⋯N hydrog...

An enhanced fluorescent emission of the dye Rhodamine 800 in the Near-IR is observed in the presence of other xanthene dye molecules (RhX) when they are hosted in different matrices due to the formation of a new type of fluorescent J-heteroaggregates. This enhanced emission of the acceptor occurs despite the low spectral overlapping and the low quantum yield of Rh800.

In the title mol-ecule, C(30)H(36)N(4)O(3), the dihedral angle between the planes of the xanthene and spiro-lactam rings systems is 88.69 (4)°. Both C atoms of one of the ethyl groups are disordered over two sites with occupancies 0.72 (2)/0.28 (2). The conformation of the mol-ecule may be influenced by two intra-molecular hydrogen bonds.

Novel representatives of the important group of biologically active dibenzosuberone derivatives were prepared: 3,7-dibromo-5-(dimethylaminoethyl- oxyimino)-10,11-dihydro-5H-dibenzo[a,d]cyclohepta-1,4-diene (1), 3,7-dibromo-5-(3- dimethylaminopropylidene)-10,11-dihydro-5H-dibenzo[a,d]cycloheptene (2) and 1,7- dibromo-5-(3-dimethylaminopropylidene)-10,11-dihydro-5H-dibenzo-[a,d]-cycloheptene (3)....

The title compound, C(35)H(36)N(4)O(4), was prepared as a spiro-lactam ring formation of rhodamine B dye for comparison with a ring-opened form. The xanthene ring system is approximately planar. The r.m.s. deviation from planarity is 0.064 (6) Å for the xanthene ring. The dihedral angles formed by the spiro-lactam and 2,4-dihydroxy-benzene rings with the xanthene ring system are 86.6 (9) and 88...

In the mol-ecule of the title compound, C(24)H(28)O(4), the three six-membered rings of the xanthene system are not planar, having envelope, boat and envelope conformations. In the crystal structure, C-H⋯O hydrogen bonds link the mol-ecules, generating centrosymmetric R(2) (2)(12), R(4) (4)(28) and R(2) (2)(16) ring motifs and forming a three-dimensional network.

A series of dibenzo[b,e]ox(thi)epin-11(6H)-one O-benzoyloximes has been synthesized and structurally elucidated by means of IR, (1)H-NMR, (13)C-NMR, MS, and elemental analysis. The newly developed compounds were screened at concentrations of 200-25 μg/mL for their antibacterial activity against Gram+ve organisms such as Methicillin-Resistant Staphylococcus Aureus (MRSA), Gram-ve organisms such ...

In the title compound, C(14)H(10)O(4)·H(2)O, isolated from the roots of Calophyllum membranaceum, the xanthene ring system is almost planar (r.m.s. deviation = 0.008 Å). In the crystal structure, inter-molecular O-H⋯O and O-H⋯(O,O) hydrogen bonds connect the mol-ecules.

In the title mol-ecule, C(39)H(45)NO(6), the two tetra-methyl-octa-hydroxanthen-1,8-dione substituents are arranged approximately parallel to each other and approximately perpendicular to the plane of the pyridine ring. The six-membered xanthene rings adopt flattened boat conformations with the O and methine C atoms deviating from the plane of the other four atoms.