Cycloaddition reactions of polyenic donor-π-acceptor systems with an electron-rich alkyne: Access to new chromophores with second-order optical nonlinearities

摘要

The formal [2 + 2] cycloaddition-cycloreversion (CA-CR) between 4-ethynyl-N,N-dimethylaniline and polyenic Donor-π-Acceptor (D-π-A) systems takes place to yield compounds bearing two donors and one acceptor. Structural, linear and second-order nonlinear optical (NLO) properties of the new molecules reveal the stronger polarization of these systems when compared to analogous merocyanines lacking the dimethylaminophenyl (DMA) ring. © 2012 The Royal Society of Chemistry.