Crystal structure of (Z)-1-(ferrocenylethynyl)-10-(phenylimino)anthracen-9(10H)-one from synchrotron X-ray powder diffraction

In a ferrocenyl–anthracen-9(10H)-one compound that has been designed and synthesized to explore a new electron-donor (D) and -acceptor (A) conjugated complex, the two cyclopentadienyl rings adopt an eclipsed conformation. The anthracene tricycle is distorted towards a butterfly conformation.


Chemical context
Compounds containing a mixture of electron-donor (D) and -acceptor (A) molecules have attracted much attention owing to their unique structures and various characteristic properties (Alberola et al., 2003;Ferraris et al., 1973). D-A-conjugated complexes of ferrocenylethynylanthraquinones (FcAq) demonstrate guest-molecule absorption and valence tautomerization etc. We have synthesized the title compound 1-(ferrocenylethynyl)-10-(phenylimino)anthracen-9(10H)one [1-(Fc)AqPHI] and herein we report its crystal structure, determined by synchrotron radiation (SR) X-ray powder diffraction. Fig. 1 shows the molecular structure of 1-(Fc)AqPHI, which contains two five-membered and four six-membered carbon rings. The two cyclopentadienyl rings adopt an eclipsed conformation. The anthracene tricycle is distorted towards a butterfly conformation, and the mean planes of the outer benzene rings are inclined each to other at 22.7 (3) . ISSN 1600-5368

Supramolecular features
In the crystal (Fig. 2),interactions (Table 1) between the Aq parts of the molecules pair them into inversion dimers, and weak intermolecular C-HÁ Á Á interactions (Table 2) link further these dimers into one-dimensional columns along the b axis, with the ferrocenylethynyl arms arranged between the stacks to fill the voids.

Refinement details
The size of 1-(Fc)AqPHI crystals was small, less than 1 mm. SR powder-diffraction techniques were employed for the structure determination. The powder crystallites were installed in a The molecular structure of 1-FcAqPHI, showing the atomic numbering and 50% probability displacement spheres.
Cg1 is the centroid of the C9-C14 ring. (1) 3.588 (4) 143 (1) 0.4 mm glass capillary. The X-ray powder diffraction data were measured using a large Debye-Scherrer camera with an imaging-plate (IP) as a detector installed at SPring-8 BL02B2 (Nishibori et al., 2001). The CeO 2 (NIST SRM674a) standard powder sample was used for wavelength calibration. The calibrated wavelength was 0.80200 (1) Å . The powder profile was measured at 100 K with 120 min X-ray exposure time.
Indexing was carried out using the program DICVOL04 (Boultif & Louer, 2004). The first 21 peaks of the powder pattern were completely indexed on the basis of a monoclinic cell. The figure of merit F(21) was 63.2. The space group P2 1 /n was assigned on the basis of systematic extinctions.
The lattice constants were refined by the Le Bail method using the program SP (Nishibori et al., 2007). The crystal structure was determined from powder diffraction data using a direct-space method with a genetic algorithm (Harris et al., 1998;Nishibori et al., 2008). The molecular structure model for GA was constructed using similar structures, 1,4-Fc 2 Aq, 1,5-Fc 2 Aq, and 1,8-Fc 2 Aq (Kondo et al., 2006, Murata et al., 2001. The chemically equivalent distances were equal in the model. GA analysis using the P2 1 /n space group was performed. A solution was obtained. The rigid-body Rietveld refinement was initially carried out using the program SP. Restraint Rietveld analysis was employed for the final refinement, with chemically equivalent distances being equal. Displacement parameters were refined as isotropic. Four common U iso parameters were refined for several groups of C atoms in the Aq fragment: C1-C14, phenyl ring C19-C24, and CP rings C25-C29 and C30-C34. One common U iso parameter was also refined for carbon atoms at the D-A junction (C17 and C18). U iso for H atoms connected to the Aq and Ph parts were fixed at 0.05 Å 2 . U iso for H atoms connected to the C25-C29 and C30-C34 CP rings were fixed at 0.09 Å 2 and 0.04 Å 2 , respec-    (Toraya, 1990) was used with strain broadening (Stephens, 1999). Results of the Rietveld refinements are shown in Fig. 3. Crystal data, data collection and structure refinement details are summarized in Table 3. Crystal structure of (Z)-1-(ferrocenylethynyl)-10-(phenylimino)anthracen-9(10H)-one from synchrotron X-ray powder diffraction Eiji Nishibori, Shinobu Aoyagi, Makoto Sakata, Ryota Sakamoto and Hiroshi Nishihara