| aDisplay requires a Java-enabled Web browser, 3D models and 2D diagrams being invoked by clicking on any of the labelled buttons in the top navigation window. The resulting Jmol display can also be controlled by a pull down menu produced by a right-mouse click in the right hand viewing window, from which individual coordinate files can also be acquired. bComputational details: Molecular geometries were optimised at the ωB97XD density functional level (a dispersion corrected procedure to account for stacking effects, Chai, J. -D. and Head-Gordon, M., Phys. Chem. Chem. Phys., 2008, 6615-20. DOI: 10.1039/B810189B) and a 6-311G(d,p) basis set, with a self-consistent-reaction-field (SCRF) solvent correction specifying acetonitrile. Chiro-optical properties were computed for both the ωB97XD and the CAM-B3LYP functional, the latter having been shown to provide the best average description of such properties (Rivera-Fuentes, P., Alonso-Gomez, J. L., Petrovic, A. G., Seiler, P., Santoro, F., Harada, N., Berova, N., Rzepa, H. S., and Diederich, F., Chem. Euro J., 2010, DOI: 10.1002/chem.201001087). Such procedures have previously indentified a possible mis-assignment of a helical octaphyrin (Rzepa, H. S., Org. Lett., 2009, 11, 3088-3091. DOI: 10.1021/ol901172g). cOptical calculation calculated at 589nm. dElectronic circular dichroism spectrum calculated using time-depdendent DFT, specifying NStates = 50 or 30. eOAI-PMH compliant Digital repository identifier, resolved as e.g. http://dx.doi.org/10042/to-5700 fThis procedure was initially calibrated for (M,1S)-(-)-5, as reported by Starý and co (Stará, I. G.; Alexandrová, Z.; Teplý, F.; Sehnal, P.; Starý, I.; Šaman, D.; Buděšínský, M.; Cvaka, J. Org. Lett. 2005, 7, 2547-2550. DOI: 10.1021/ol047311p). The reported optical rotation of -674° compares with a calculated value of -526°. Typically, calculated rotations are under-estimated. g The sign of the optical rotation is due to the (M) helix rather than the (1S) stereocentre, as shown by a calculated positive rotation for the (P,1S) diastereomer. h Measured value in this work. iωB97XD DFT level. jCAM-B3LYP DFT level. kResults of Starý and co. lThis work. |