New supramolecular compounds based on porphyrin and polyoxometalate: synthesis, characterization and nonlinear optical and optical limiting properties
New supramolecular compounds based on porphyrin and polyoxometalate: synthesis, characterization and nonlinear optical and optical limiting properties
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基于卟啉和多金属氧酸盐的新型超分子化合物：合成、表征以及非线性光学和光限幅特性
DOI：
10.1039/c4ra09384d
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发表时间：
2014-01-01
期刊：
影响因子：
3.9
通讯作者：
Asif, Hafiz Muhammad
中科院分区：
文献类型：
--
作者：
Shi, Zonghai;Zhou, Yunshan;Asif, Hafiz Muhammad
三个新的超分子化合物[H2 TPP]（1.5）[SW 11 VO 40]中心点5CH（3）CN中心点4 H（2）O 1，[H2 TPP]（2）[SW 10 V2 O 40]中心点4CH（3）CN中心点3 H（2）O 2，和由[H2 TPP]（2+）阳离子和钒取代的Keggin型多氧六环酸盐（POM）阴离子[SW 12-nVnO 40]组成的[H2 TPP][SW 12 O 40]中心点4 H（2）O 3，制备并表征了（2+n）-）（n = 0-2）。利用Nd：YAG激光器，在532 nm，脉冲宽度τ = 7 ns的条件下，研究了所得杂化材料的三阶非线性光学（NLO）和光限幅（OL）特性。结果表明，所有这些超分子化合物都具有明显的非线性反饱和吸收、自散焦行为和良好的光学性能，特别是化合物1，其具有7.05 × 10（-29）（esu）的第二超极化率γ值，并表现出与最公知的OL材料如In（Pc*）相当的OL性能。Cl表明它们是潜在的优良NLO材料。值得注意的是，还观察到对应于不同起始还原电位的POM阴离子中的钒取代度影响所得化合物的NLO和OL性质：化合物2的三阶NLO和OL性质劣于化合物1的那些，并且优于化合物3的那些。观察到它们的第二超极化率γ值和OL性能与所得化合物的HOMO-LUMO间隙成反比。研究表明，在激光辐照下，超分子化合物中卟啉与POM阴离子之间的激发态电荷转移是增强非线性光学和线性光学响应的关键。
Three new supramolecular compounds [H2TPP](1.5)[SW11VO40]center dot 5CH(3)CN center dot 4H(2)O 1, [H2TPP](2)[SW10V2O40]center dot 4CH(3)CN center dot 3H(2)O 2, and [H2TPP][SW12O40]center dot 4H(2)O 3 composed of [H2TPP](2+) cation and vanadium substituted Keggin-type polyoxometalate (POM) anion [SW12-nVnO40]((2+n)-) (n = 0-2) were prepared and characterized. The third-order nonlinear optical (NLO) and optical limiting (OL) properties of resulting hybrids were studied by using an Nd:YAG laser at 532 nm with a pulse duration of tau = 7 ns. The results demonstrate that all of these supramolecular compounds have significant nonlinear reverse saturated absorption, self-defocusing behavior, and good OL performance, especially for compound 1, which has a second hyperpolarizability gamma value of 7.05 x 10(-29) (esu) and exhibits a comparable OL performance with the most well-known OL materials such as In(Pc*)Cl indicating that they are potentially excellent NLO materials. Remarkably, it was also observed that the degree of vanadium substitution in POM anions corresponding to different onset of reduction potential influences the NLO and OL properties of the resulting compounds: third-order NLO and OL properties of compound 2 are inferior to those of compound 1, and are better than those of compound 3. Both their second hyperpolarizability gamma values and the OL performance were observed to be inversely proportional to the HOMO-LUMO gaps of the resulting compounds. The excited charge transfer from porphyrin to POM anions in the supramolecular compounds when exposed to laser irradiation is thought to play key role in the enhancement of NLO and OL response.