Methyl 2-amino-5-chlorobenzoate

Acta Crystallographica Section E Structure Reports Online (Impact Factor: 0.35). 11/2010; 66(Pt 11):o3025. DOI: 10.1107/S1600536810042510
Source: PubMed

ABSTRACT The title compound, C(8)H(8)ClNO(2), is almost planar, with an r.m.s. deviation of 0.0410 Å from the plane through the non-hydrogen atoms. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains along the b axis. An intra-molecular N-H⋯O hydrogen bond results in the formation of a six-membered ring.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Automated structure validation was introduced in chemical crystallography about 12 years ago as a tool to assist practitioners with the exponential growth in crystal structure analyses. Validation has since evolved into an easy-to-use checkCIF/PLATON web-based IUCr service. The result of a crystal structure determination has to be supplied as a CIF-formatted computer-readable file. The checking software tests the data in the CIF for completeness, quality and consistency. In addition, the reported structure is checked for incomplete analysis, errors in the analysis and relevant issues to be verified. A validation report is generated in the form of a list of ALERTS on the issues to be corrected, checked or commented on. Structure validation has largely eliminated obvious problems with structure reports published in IUCr journals, such as refinement in a space group of too low symmetry. This paper reports on the current status of structure validation and possible future extensions.
    Acta Crystallographica Section D Biological Crystallography 03/2009; 65(Pt 2):148-55. DOI:10.1107/S090744490804362X · 7.23 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An account is given of the development of the SHELX system of computer programs from SHELX-76 to the present day. In addition to identifying useful innovations that have come into general use through their implementation in SHELX, 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. SHELXL is the most widely used program for small-molecule refinement and SHELXS and SHELXD are often employed for structure solution despite the availability of objectively superior programs. SHELXL also finds a niche for the refinement of macromolecules against high-resolution or twinned data; SHELXPRO acts as an interface for macromolecular applications. SHELXC, SHELXD and SHELXE are proving useful for the experimental phasing of macromolecules, especially because they are fast and robust and so are often employed in pipelines for high-throughput phasing. This paper could serve as a general literature citation when one or more of the open-source SHELX programs (and the Bruker AXS version SHELXTL) are employed in the course of a crystal-structure determination.
    Acta Crystallographica Section A Foundations of Crystallography 02/2008; 64(Pt 1):112-22. DOI:10.1107/S0108767307043930 · 2.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The behaviour of Rogers's η parameter for enantiomorph-polarity estimation is examined theoretically and experimentally on simulated intensity data for seven well-assorted compounds. An alternative parameter x, based on incoherent scattering from twin components related by a centre of symmetry, is also considered. It is found that both parameters are very well adapted to implementation in a least-squares program and converge well. The η parameter can give false and over-precise indications of chirality-polarity for structures which are nearly centrosymmetric, whereas the x parameter does not have this fault and converges more rapidly than η.
    Acta crystallographica. Section A, Foundations of crystallography 11/1983; 39(6):876-881. DOI:10.1107/S0108767383001762 · 2.07 Impact Factor

Preview (2 Sources)

Available from