The Crystal Structure of 4-Iodoacetophenone Azine


4-Iodoacetophenone azine crystallizes in the space group Pbcn with cell parameters a = 34.5187(19), b = 7.2638(4), and c = 6.3736(3) Å. The azine shows a gauche conformation with regard to the N - N bond and the phenyl rings are twisted in a way that leads to the largest possible twist between the benzene rings of each azine. This azine conformation allows for intermolecular arene-arene T-contacts between pairs of benzene rings and these double-T contacts involve only molecules within the same layer. All azines are perfectly colinear within each layer and this results in a quadrilateral kite-shaped arrangement of iodine atoms at the interface of each layer. The iodine-iodine distances within each layer are 4.5 and 5.1 Å, and the three unique angles of the kite-shaped quadrilaterals are 97.1, 76.9, and 88.8°. The iodine atoms in adjacent layers pack such that atoms of one layer fill the square interstices of the next layer. The distances between iodine atoms in adjacent layers are 4.5 and 4.1 Å. The C - I bonds are not orthogonal to the I-planes and the direction of the molecules in adjacent layers causes a deviation of about 40° from colinearity.



Keywords and Phrases

Arene-arene contacts; Azines; Intermolecular interactions; Iodine-iodine interactions; Nonlinear optics; Quadrupole interactions

International Standard Serial Number (ISSN)

1074-1542; 1572-8854

Document Type

Article - Journal

Document Version


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© 1999 Springer Verlag, All rights reserved.

Publication Date

01 Sep 1999