Mixed Derivatives Based on Arylphosphino Units

Diphenylphosphino moieties have been investigated as auxiliary donor groups for the tailoring of potential second- and third-order NLO-phores, although their jr-donating ability is clearly much lower than that of diarylamino units. The P-based systems are prepared using classical synthetic transformations (e.g. Wittig 

The UV-Vis data suggest that the subchromophores in 135 and 136 are near to being electronically independent. Derivative 135 has a small dipole moment and can be considered as an almost purely octupolar system, as is also the case for 136. Compared with their tin analogs, the phosphorus derivatives 135 and 136 have higher /3 values owing to the more efficient acceptor nature of the phospho-nium moiety [73 a]. Furthermore, the NLO activity of the octupolar compound 135 is almost three times larger than that of the dipolar subchromophore 137 

4 Design of Jt-Conjugated Systems Using Organophosphorus Building Blocks 

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