3000
N.P. Rath et al. / Inorganica Chimica Acta 360 (2007) 2997–3001
4. Conclusion
To summarize, two concomitant polymorphs of 1 have
been structurally characterized by low temperature single
crystal X-ray diffraction studies. In both polymorphic
modifications, weak hydrogen bonding mediates distinct
supramolecular pillared-layer structures and hexagonal
networks. In addition to being an example of concomitant
polymorphism, the organometallic compound 1 also exhib-
its conformational polymorphism and supramolecular
isomerism. The chemical basis for the simultaneous occur-
rence of concomitant polymorphism and conformational
polymorphism is most likely due to the comparable energy
scale for these two phenomena.
Fig. 4. Hexagonal pattern observed in form B.
Acknowledgement
Funding from the National Science Foundation for pur-
chase of the X-ray diffractometer is acknowledged.
Appendix A. Supplementary material
CCDC 632382 and 632381 contain the supplementary
graphic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK; fax: (+44) 1223-336-033; or e-mail: depos-
it@ccdc.cam.ac.uk. Supplementary data associated with
Fig. 5. The 3D structure in form B.
atom forms bifurcated hydrogen bonds. Each molecule in
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