Synthesis and Optical Characterization of Polydiacetylenes Containing Carboxylic Acid, Carbamate, Phosphonium, and Quaternary Ammonium Functionalities

Abstract

Symmetrically substituted 1,3-diynes, X(CH 2 ) n C⋮C C⋮C(CH 2 ) n X (X = Et 2 N; n = 4, 9; 1d,e ) have been prepared from the appropriate bis-tosylates (X = OSO 2 C 6 H 4 Me- p; 1b,c ) and diethylamine, and one such derivative has been converted into a bis-quaternary ammonium salt (X = N + Et 2 MeI -; n = 4; 1f ) and an ammonium sulfonate inner salt (X = N + Et 2 (CH 2 ) 3 SO 3 -; n = 4; 1g ), respectively. Three bis-phosphonium salts, X(CH 2 ) n C⋮C C⋮C(CH 2 ) n X (X = P + Ph 3 Br -; n = 4, 9, 3; 1h − j ), were synthesized from 1,4-bis(bromoalkyl)-1,3-diynes and the appropriate phosphine derivative. The new diyne derivatives did not polymerize on exposure to γ-irradiation or electron beam irradiation in a Van der Graff linear accelerator. The tosylated polydiacetylene (PDA) derivative (2 a, “PTS-12”) derived from 1b was treated with diethylamine to yield a tertiary amine-functionalized PDA derivative ( 2b ), and the latter was allowed to react (separately) with methyl iodide and 1,3-propanesultone to give ionomeric PDAs 2c and 2d, respectively. The phosphinated PDA ( 2e ) was synthesized from PTS-12 ( 2a ) and diphenylphosphinyllithium or -potassium, and this material was used to prepare the PDA phosphonium salt 2f . The nonlinear optical properties of selected new PDAs ( 2c,d,f ), as well as some known PDAs, were evaluated by means of the z -scan technique. The magnitudes of two-photon absorption coefficients (β) were determined and are discussed.