In the title compound C14H14BrNO3, the coumarin ring system is almost planar (r.m.s. deviation = 0.008 Å) and an intra-molecular C - H⋯O inter-action generates an S(6) ring. In the crystal, mol-ecules are linked by N - H⋯O hydrogen bonds, with the C=O unit of the coumarin ring system acting as the acceptor group, generating [010] C(8) chains. The chain connectivity is reinforced by two C - H⋯O inter-actions.

R. Dhamodharan

Department Of Chemistry

Venkatachalam Ramkumar

Fulltext

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IIT Madras

2-Bromo-2-methyl-N-(4-methyl-2-oxo-2H-chromen-7-yl)propanamide.

Acta Crystallographica Section E: Structure Reports Online

The mol-ecular structure of the title compound, C 14H 18Br 2N 2O 2, has one half-mol-ecule in the asymmetric unit. The mol-ecule has a crystallographic inversion centre in the middle of the benzene ring. The C - C - N - C torsion angle between the benzene ring and the bromo-amide group is 149.2 (7)°. The crystal is stabilized by a strong inter-molecular N - H⋯O bond and weak C - H⋯O inter-actions. These contacts give rise to a three-dimensional network.

N,N′-(1,4-Phenylene)bis(2-bromo-2-methylpropanamide)

In the title compound, C14H10BrF3O 4, the coumarin ring system is almost plannar (r.m.s. deviation = 0.025 Å) and a short C-H⋯F contact occurs. The propanoate fragment is orientated almost perpendicular to the ring [dihedral angle = 71.80 (12)°]. In the crystal, molecules are linked by C-H⋯O hydrogen bonds, generating [100] chains.

2-Oxo-4-trifluoromethyl-2H-chromen-7-yl 2-bromo-2-methylpropanoate

Macromolecules

Synthesis, Characterization, and Properties Evaluation of Methylcoumarin End-Functionalized Poly(methyl methacrylate) for Photoinduced Drug Release

<jats:p>An account is given of the development of the<jats:italic>SHELX</jats:italic>system of computer programs from<jats:italic>SHELX</jats:italic>-76 to the present day. In addition to identifying useful innovations that have come into general use through their implementation in<jats:italic>SHELX</jats:italic>, a critical analysis is presented of the less-successful features, missed opportunities and desirable improvements for future releases of the software. An attempt is made to understand how a program originally designed for photographic intensity data, punched cards and computers over 10000 times slower than an average modern personal computer has managed to survive for so long.<jats:italic>SHELXL</jats:italic>is the most widely used program for small-molecule refinement and<jats:italic>SHELXS</jats:italic>and<jats:italic>SHELXD</jats:italic>are often employed for structure solution despite the availability of objectively superior programs.<jats:italic>SHELXL</jats:italic>also finds a niche for the refinement of macromolecules against high-resolution or twinned data;<jats:italic>SHELXPRO</jats:italic>acts as an interface for macromolecular applications.<jats:italic>SHELXC</jats:italic>,<jats:italic>SHELXD</jats:italic>and<jats:italic>SHELXE</jats:italic>are proving useful for the experimental phasing of macromolecules, especially because they are fast and robust and so are often employed in pipelines for<jats:italic>high-throughput</jats:italic>phasing. This paper could serve as a general literature citation when one or more of the open-source<jats:italic>SHELX</jats:italic>programs (and the Bruker AXS version<jats:italic>SHELXTL</jats:italic>) are employed in the course of a crystal-structure determination.</jats:p>

Journal	Acta Crystallographica Section E: Structure Reports Online
ISSN	16005368
Open Access	Yes