A new zwitterionic salt for non-linear optics: {4′-[methyl(diphenyl)phosphonio]biphenyl-4-yl}triphenylborate
Abstract
The synthesis of {4′-[methyl(diphenyl)phosphonio]biphenyl-4-yl}triphenylborate (PBB) and 4′-(diphenylphosphino)biphenyl-4-yl(methyl)diphenylphosphonium hexafluorophosphate (PBP) is described. The properties of PBP and PBB are investigated by absorption and fluorescence spectroscopy. Diphenylphosphine is found to be a weaker donor group than the triphenylborate anion. The variation of dipole moment between excited and ground states as well as the hyperpolarisability coefficient, determined for PBB by solvatochromic methods, shows that this compound is promising for second-harmonic generation.