From Simplicity to Complexity in Grafting Dawson-Type Polyoxometalates on Porphyrin, Leading to the Formation of New Organic-Inorganic Hybrids for the Investigation of Third-Order Optical Nonlinearities.
From Simplicity to Complexity in Grafting Dawson-Type Polyoxometalates on Porphyrin, Leading to the Formation of New Organic-Inorganic Hybrids for the Investigation of Third-Order Optical Nonlinearities.
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DOI：
10.1021/acs.inorgchem.9b01163
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发表时间：
2019-06
影响因子：
4.6
通讯作者：
Arshad Iqbal;H. M. Asif;Yunshan Zhou;Lijuan Zhang;Ting Wang;Farooq Khurum Shehzad;Xiaoyu Ren
中科院分区：
文献类型：
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作者：
Arshad Iqbal;H. M. Asif;Yunshan Zhou;Lijuan Zhang;Ting Wang;Farooq Khurum Shehzad;Xiaoyu Ren
四种新型有机-无机杂化物，[N(C4H9)4]5H[{HNC2O(CH2O)3P2V3W15O59}C44N4H29O3] (TPPOH-1POM)、[N(C4H9)4]10H2[{HNC2O(CH2O)3P2V3W15O59}2C44N4H28O2] (TPPOH-2POM 反式)、[N(C4H9)4]10H2[{HNC2O(CH2O)3P2V3W15O59}2C44N4H28O2] (TPPOH-2POM 顺式)，和[N(C4H9)4]15H3[{HNC2O(CH2O)3P2W15V3O59}3C44N4H27O] (TPPOH-3POM)，通过将 Dawson 型多金属氧酸盐 (POM) [N(C4H9)4]5[H4P2W15V3O62] 共价接枝到新的卟啉上合成N-[1,3-二羟基-2-（羟甲基）丙-2-基]-4-[10,15,20-三（4-羟苯基）卟啉-5-基]苯甲酰胺（TPPOH-1Tris），4,4'-[5,15-双（4-羟苯基）卟啉-10,20-二基]双[ N-[1,3-二羟基-2-(羟甲基)丙-2-基]苯甲酰胺](TPPOH-2Tris反式)，4,4'-[10,15-双(4-羟基苯基)卟啉-5,20-二基]双[N-[1,3-二羟基-2-(羟甲基)丙-2-基]苯甲酰胺](TPPOH-2Tris顺式)。和4,4',4"-[20-(4-羟苯基)卟啉-5,10,15-三基]三[N-[1,3-二羟基-2-(羟甲基)丙-2-基]苯甲酰胺](TPPOH-3Tris)，分别在氮气下的N,N-二甲基乙酰胺中。通过元素分析、FT-IR、NMR（1H、2D NOESY、31P 和 51V）、ESI-MS、MALDI-TOF-MS、UV-vis 和荧光光谱对杂化化合物进行了彻底表征。所有卟啉及其相应的杂化物在激光照射下均表现出显着的三阶非线性光学响应，焦点E0处的光强为4.2 μJ，波长为532 nm，脉冲持续时间τ = 6 ns，重复频率为10 Hz。杂化物（TPPOH-1POM，TPPOH-2POM反式，TPPOH-2POM顺式，TPPOH-3POM）的分子第二超极化（γ）值计算为8.48×10-28 esu，8.94×10-28 esu，10.16×10-28 esu和8.93×10-28 esu，而相应的卟啉前体（TPPOH-1Tris、TPPOH-2Tris trans、TPPOH-2Tris cis 和 TPPOH-3Tris）的分子第二超极化率（γ）分别为 7.19 × 10-28 esu、8.09 × 10-28 esu、9.07 × 10-28 esu 和 7.24 × 10-28分别是esu。发现顺式形式的 γ 值优于所有其他化合物，这表明与其他化合物相比，顺式形式的较大偶极矩和较低的对称性发挥了重要作用。研究还发现，杂化物TPPOH-1POM、TPPOH-2POM trans、TPPOH-2POM cis和TPPOH-3POM的荧光强度相对于其相应的前体分别降低了81.52%、90.37%、93.93%和84.62%，这表明Dawson型POM是一种强猝灭剂。这种猝灭现象不仅再次明确地表明了杂化化合物的形成，而且还可能意味着从卟啉部分到道森型 POM 部分有利于光诱导电子/能量转移过程。
Four new organic-inorganic hybrids, [N(C4H9)4]5H[{HNC2O(CH2O)3P2V3W15O59}C44N4H29O3] (TPPOH-1POM), [N(C4H9)4]10H2[{HNC2O(CH2O)3P2V3W15O59}2C44N4H28O2] (TPPOH-2POM trans), [N(C4H9)4]10H2[{HNC2O(CH2O)3P2V3W15O59}2C44N4H28O2] (TPPOH-2POM cis), and [N(C4H9)4]15H3[{HNC2O(CH2O)3P2W15V3O59}3C44N4H27O] (TPPOH-3POM), have been synthesized by covalently grafting the Dawson-type polyoxometalate (POM) [N(C4H9)4]5[H4P2W15V3O62] onto new porphyrins N-[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]-4-[10,15,20-tris(4-hydroxyphenyl)porphyrin-5-yl]benzamide (TPPOH-1Tris), 4,4'-[5,15-bis(4-hydroxyphenyl)porphyrin-10,20-diyl]bis[ N-[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]benzamide] (TPPOH-2Tris trans), 4,4'-[10,15-bis(4-hydroxyphenyl)porphyrin-5,20-diyl]bis[ N-[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]benzamide] (TPPOH-2Tris cis). and 4,4',4″-[20-(4-hydroxyphenyl)porphyrin-5,10,15-triyl]tris[ N-[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]benzamide] (TPPOH-3Tris), respectively, in N, N-dimethylacetamide under nitrogen. The hybrid compounds were thoroughly characterized by elemental analysis, FT-IR, NMR (1H, 2D NOESY, 31P, and 51V), ESI-MS, MALDI-TOF-MS, UV-vis, and fluorescence spectroscopy. All porphyrins and their corresponding hybrids exhibited remarkable third-order nonlinear-optical responses under laser irradiation, with the intensity of light at focus E0 being 4.2 μJ at wavelength 532 nm, pulse duration τ = 6 ns, and repetition rate 10 Hz. The molecular second hyperpolarizability (γ) values of the hybrids (TPPOH-1POM, TPPOH-2POM trans, TPPOH-2POM cis, TPPOH-3POM) were calculated to be 8.48 × 10-28 esu, 8.94 × 10-28 esu, 10.16 × 10-28 esu, and 8.93 × 10-28 esu, while the molecular second hyperpolarizability (γ) of their corresponding porphyrin precursors (TPPOH-1Tris, TPPOH-2Tris trans, TPPOH-2Tris cis, and TPPOH-3Tris) were 7.19 × 10-28 esu, 8.09 × 10-28 esu, 9.07 × 10-28 esu, and 7.24 × 10-28 esu, respectively. The γ values of the cis forms were found to be superior to those of all other compounds, indicating the significant role of the greater dipole moment and low symmetry of the cis form compared to other compounds. It was also found that the fluorescence intensity was decreased by 81.52%, 90.37%, 93.93%, and 84.62% for the hybrids TPPOH-1POM, TPPOH-2POM trans, TPPOH-2POM cis, and TPPOH-3POM with respect to their corresponding precursors, respectively, which reveals the Dawson-type POM as a strong quencher. This quenching phenomenon not only indicates again unequivocally the formation of hybrid compounds but also may imply a photoinduced electron/energy-transfer process favored from a porphyrin moiety to a Dawson-type POM moiety.