A second monoclinic polymorph for 3-amino-1-(4-meth­oxy­phen­yl)-9,10-dihydro­phenanthrene-2,4-dicarbonitrile

Acta Crystallographica Section E Structure Reports Online (Impact Factor: 0.35). 04/2012; 68(Pt 4):o1157-8. DOI: 10.1107/S1600536812011798
Source: PubMed


The title compound, C(23)H(17)N(3)O, has been previously described in a monoclinic P2(1)/c polymorph with Z = 4 [Asiri, Al-Youbi, Faidallah, Ng & Tiekink (2011). Acta Cryst. E67, o2449]. In the new monoclinic P2(1)/n form, with Z = 8, there are two independent mol-ecules, A and B, in the asymmetric unit. In both mol-ecules, the cyclo-hexa-1,3-diene ring has a screw-boat conformation, whereas it is a distorted half-chair in the original polymorph. There is a fold in each mol-ecule, as indicated by the dihedral angle between the benzene rings of the 1,2-dihydro-naphthalene and aniline residues of 33.19 (10)° (mol-ecule A) and 30.6 (10)° (mol-ecule B). The meth-oxy-benzene ring is twisted out of the plane of the aniline residue to which it is connected [dihedral angles = 49.22 (10) and 73.27 (10)°, in A and B respectively]. In the crystal, the two independent mol-ecules self-associate via N-H⋯N hydrogen bonds, generating a 12-membered {⋯HNC(3)N}(2) synthon. These are connected into a supra-molecular tape in the (-101) plane by N-H⋯O(meth-oxy) inter-actions. In the P2(1)/c polymorph, supra-molecular layers are formed by N-H⋯N and N-H⋯O inter-actions.

Download full-text


Available from: Abdullah M. Asiri, Oct 01, 2015
1 Follower
27 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the title compound, C20H13N3S, the partially saturated ring adopts a twisted half-boat conformation with the methyl­ene C atom closest to the amino­benzene ring lying 0.690 (6) Å out of the plane defined by the five remaining atoms. The dihydro­phenanthrene residue has a folded conformation [dihedral angle between the outer benzene rings = 26.27 (18)°]. The thio­phen-2-yl ring forms a dihedral angle of 63.76 (19)° with the benzene ring to which it is attached. In the crystal, inversion dimers linked by pairs of N—H⋯N hydrogen bonds generate R 2 2(12) loops. The dimers are linked into layers in the bc plane by weak C—H⋯π inter­actions. The thio­phen-2-yl ring is disordered over two essentially coplanar but opposite orientations in a 0.918 (4):0.082 (4) ratio.
    Acta Crystallographica Section E Structure Reports Online 04/2012; 68(Pt 4):o1027-8. DOI:10.1107/S1600536812010033 · 0.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The asymmetric unit of the 1:19 title co-crystal of 2-amino-4-(3,4-dimeth­oxy­phen­yl)-5,6-dihydro­benzo[h]quinoline-3-carbo­nitrile and 3-amino-1-(3,4-dimeth­oxy­phen­yl)-9,10-dihydro­phenanthrene-2,4-dicarbonitrile, 0.05C22H19N3O2·0.95C24H19N3O2, has the atoms of the fused-ring system and those of the amino, cyano and dimeth­oxy­phenyl substitutents overlapped. The fused-ring system is buckled owing to the ethyl­ene linkage in the central ring with the two flanking aromatic rings being twisted by 31.9 (1)°. The ring of the dimeth­oxy­phenyl substituent is twisted by 72.4 (1)° relative to the amino- and cyano-bearing aromatic ring. In the crystal, mol­ecules are linked by duplex amine N—H⋯O(meth­oxy) hydrogen bonds in a cyclic association [graph-set R 2 2(7)], generating a helical chain structure extending along [201].
    Acta Crystallographica Section E Structure Reports Online 11/2011; 67(Pt 11):o2873. DOI:10.1107/S1600536811040517 · 0.35 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 · 2.31 Impact Factor