Vibrational properties of [3₃](1,3,5)-cyclophane and bridged-hexaprismane

Full geometry optimization yielded unexpected bond length alternations of [3₃](1,3,5)-cyclophane as well as bridged hexaprismane. According to NICS calculations, aromaticity of [3₃](1,3,5)-cyclophane is slightly reduced but it is still quite aromatic. The peaks at 1456 and 1439 cm^-1 turned out to be the conformation indicators. On the basis of these peaks, it is concluded that the inter-molecular forces in the condensed phase determine the conformational distributions. The peaks at 1215, 1200, 1171 and 1114 cm^-1 of the bridged hexaprismane were found to be the characteristic peaks of prismane.