نتایج جستجو برای: xanthene
تعداد نتایج: 531 فیلتر نتایج به سال:
The β-lactam ring of the title compound, C(35)H(23)NO(2), is nearly planar with a maximum deviation of 0.003 (3) Å from the mean plane. It makes dihedral angles of 17.4 (2), 85.22 (17) and 65.39 (16)°, respectively, with the phenyl, xanthene and anthracene ring systems. In the crystal structure, there are intra-molecular C-H⋯O and C-H⋯N contacts and mol-ecules are also linked by C-H⋯π inter-act...
THE TITLE COMPOUND (SYSTEMATIC NAME 3,6-dimethyl-10-p-tolyl-9-oxa-10-phosphaanthracene), C(21)H(19)OP, is a precursor for the preparation of a bidentate xanthene-based ligand, in which the dihedral angle between the toluene ring and the phenoxaphosphine ring system is 83.26 (3)°. The geometry at the P atom is pyramidal, resulting in a longer C-P bond length as compared to the two ring C-P bonds.
In the title compound, C19H16BrClO4, both the fused xanthene rings and one of the cyclo-hexane rings adopt envelope conformations, while the other cyclo-hexane ring is in a chair conformation. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming infinite chains running along [10-1] incorporating R 2 (2)(16) ring motifs. In addition, C-H⋯π inter-actions and weak π-π stacking in...
A simple and efficient method for the synthesis of spiro[indoline-3,9'-xanthene]trione derivatives by means of condensation between isatins and 1,3-cyclohexanedione in the presence of a catalytic amount of magnesium perchlorate at 80 °C in 50% aqueous ethanol medium has been described. Notably, the present method offers desirable advantages of good yields, simplicity of workup procedure, easy p...
cellulose bonded n-propyl diethylene tetra sulfamic acid (cbpdetsa) was successfully applied as a green and recyclable acidic catalyst for the synthesis of tetrahydrobenzo [a] xanthene-11-one as an important class of potentially bioactive compounds. the products are obtained by the coupling of 2-naphtol , cyclohexadione and aldehyde derivatives in good to high yields (70- 92%) under solvent-fre...
Halogenation of organic compounds plays diverse roles in biochemistry, including selective chemical modification of proteins and improved oral absorption/blood-brain barrier permeability of drug candidates. Moreover, halogenation of aromatic molecules greatly affects aromatic interaction-mediated self-assembly processes, including amyloid fibril formation. Perturbation of the aromatic interacti...
We individuate a photoinduced electron transfer (PeT) as a quenching mechanism affecting rhodamine B photophysics in solvent. The PeT involves an electron transfer from the carboxylate group to the xanthene ring of rhodamine B. This is finely modulated by the subtle balance of coulombic and non-classical interactions between the carboxyphenyl and xanthene rings, also mediated by the solvent. We...
Some new mono-and bis-polycyclic aromatic spiro-beta-lactams and bis-non spiro-polycyclic aromatic beta-lactams have been synthesized from imines derived from anthracene-9-carbaldehyde, 2-naphtaldehyde and a ketene derived from 9H-xanthene-9-carboxylic acid and phenoxyacetic acid by a [2+2] cycloaddition reaction. The cycloadducts were characterized by spectral data, including 1H-NMR, 13C-NMR, ...
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...
In the title compound, C(33)H(38)N(4)O(3), the mean planes of the 9H-xanthene unit and spiro-lactam (nine-atom) core are almost mutually perpendicular at 87.26 (6)°. Intra-molecular N-H⋯O and C-H⋯N inter-actions influence the 4-oxo-pent-2-en-2-yl-amino conformation. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into chains along [001].
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