Synthesis and characterization of molecules and pi-conjugated materials containing low-coordinate phosphorus

There are many similarities between phosphaalkenes and phosphaalkynes, low-coordinate phosphorus compounds containing RP = CR2 and RC ≡ P functional groups, and olefins (R2C = CR2), their unsaturated carbon analogues. Phosphanylidene-sigma4-phosphoranes have proven to be phospha-Wittig reagents that react with aldehydes to generate phosphaalkenes. Using the phospha-Wittig reaction, phosphaalkene oligomers and polymers were synthesized and characterized and shown to exhibit bathochromic shifts in comparison with related olefins. meta-Terphenyl phosphaalkynes have also been prepared. These materials were prepared for possible synthesis of transition metal complexes of phosphaalkynes. In addition, phosphanylidene-sigma4-phosphoranes react with ortho -quinones to form 1,3,2-dioxaphospholanes or beta-phosphaenones depending on the nature of the quinone. Furthermore, meta-terphenyls containing methoxy groups were investigated which have different properties from those having alkyl substitutents. 2,6-Dimesitylphenyl difluorophosphine was synthesized and characterized and found to be relatively inert to reduction by active magnesium.