π-conjugated soluble nickel–polyyne copolymer: Synthesis and third-order optical nonlinearity

✍ Scribed by Mujie Yang; Lingjun Zhang; Ziqiang Lei; Peixian Ye; Jinhai Si; Qiguang Yang; Yougui Wang

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 204 KB
• Volume: 70
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19981107)70:6<1165::aid-app14>3.0.co;2-z

✦ Synopsis

By means of homogeneous stepwise condensation method, both the Nipolyyne copolymers with PPh 3 and PBu 3 ligands, and modified -conjugated nickelcontaining copolymers have been synthesized and confirmed by infrared (IR) analysis. The Ni-polyyne copolymers obtained are yellow powder having a M w of about 1 ϳ 2 ϫ 10 4 and a molecular weight distribution (MWD) of less than 3, and they are soluble in tetrahydrofuran (THF), CHCl 3 , and toluene. Their third-order nonlinear optical properties have been investigated by a degenerate four-wave mixing (DFWM) technique. The effect of the nature of the ligands attached to the nickel atoms, the structure, and the length of -conjugation between the 2 metal centers in the main chain on the hyperpolarizability ␥ of the Ni-polyyne polymers have been discussed. The maximum susceptibility (3) and hyperpolarizability ␥ of the Ni-polyyne polymers reach 5.17 ϫ 10 Ϫ12 and 2.30 ϫ 10 Ϫ30 esu, respectively.