There are three compounds: 1.) fulvene 2.) calicene 3.) I don't know the name of the third compound. It looks like calicene except that there is not a double bond inside of the three-membered ring. Anyways, it turns out that fulvene and calicene have unusually large dipole moments, but not the third compound. One answer choice was only calicene, another was both calicene and fulvene. There was no answer choice for all three. I knew that calicene definitely has a very large dipole moment, because the resonance structure formed when the pi electrons joining the two rings moves to the carbon of the pentadiene acheives two aromatic compounds. As for fulvene and the third compound, only one ring acheives aromaticity. The resonance structure for fulvene has a primary carbocation substituent, and the one for the third compound has a tertiary carbocation substituent, and angle strain. I thought that if fulvene had an unusually large dipole moment, so must the third compound. The resonance structure for compound 3 has angle strain, but I thought the overall stability would be similar to the stability of a primary carbocation. I could not choose all three, and I believed the third compound would have an equal or greater dipole moment than fulvene, so I went with just calicene. But I'm wrong. Could someone help me understand why fulvene would have a larger dipole moment than the third compound?