Accurate Crystal Structures of CHCN, CH(CN), and CHCN Valence Isomers Using Nonspherical Atomic Scattering Factors.

Fourteen crystal structures, mostly from good-quality datasets but including some marginal and twinned exemplars, from a series of novel polycyclic benzo- and naphtho-fused organic nitriles are presented and accurately described, including some related structures of a bromo-substituted and partially hydrogenated analogues. These structures represent a considerable increase in the number of published structures within their archetypes. This work highlights the significant advancement in structural refinement software proffered by NoSpherA2, which enables Hirshfeld Atom Refinement (HAR) of the structures within Olex2 v1.

(5Z,7Z,9Z)-5,10-Di-bromo-benzo[8]annulene.

In the structure of the title compound, C12H8Br2, the two bromine substituents are oriented exo to the boat-shaped cyclo-octa-tetra-ene at the two ring sites that are β to the ring fusion positions. The average Br-C bond distance is 1.919 (2) Å, the average distance for C=C double bonds that are Br substituted is 1.

A tetrabromo-1,4-ethanonaphthalene and related dibromo-1,4-ethenonaphthalene.

(1RS,3RS,4RS,10SR)-2,2,3,10-Tetrabromo-1,2,3,4-tetrahydro-1,4-ethanonaphthalene, C12H10Br4, (I), is the first structure to be reported with four Br atoms bound to a 1,4-ethanonaphthalene framework and also the first which possesses three Br atoms in exo positions. Interactions between the Br atoms [three short intramolecular Br..

Dimethyl 7-meth-oxy-tetra-cyclo-[6.4.0.0(2,4).0(3,7)]dodeca-1(12),5,8,10-tetra-ene-3,4-dicarboxyl-ate.

The title compound, C(17)H(16)O(5), is a previously unreported substituted semibulvalene cage compound (that is, a tricyclic hydro-carbon formed from one cyclo-propane and two cyclo-pentene rings which also has one double bond fused to a benzene ring). It has one meth-oxy substituent attached to the bridgehead C atom that links only the two cyclo-pentene rings and two methyl carboxyl-ate groups located on the C atom shared by all three non-benzene rings and that shared only between the cyclo-propane and the cyclo-pentene rings. The stereochemistry of the two enanti-omers (racemate) that assemble in each unit cell is RRRS and SSSR.

exo-10,11-Dibromo-tricyclo-[6.3.1.0]dodeca-2,4,6,9-tetra-ene.

The title compound, C(12)H(10)Br(2), is a bridged ring system based on a homobenzonorbornadiene framework. The exo configuration of one of the Br atoms was previously assigned via NMR correlations and has now been confirmed by the geometry of the solid-state structure. The compound features a Br-C-C-Br torsion angle of 66.