Bulbul Amir Sohel, Chaudhri Nivedita, Shanu Mohd, Acharyya Jitendra Nath, Vijaya Prakash G, Sankar Muniappan
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India.
Nanophotonics Lab, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
Inorg Chem. 2022 Jul 4;61(26):9968-9982. doi: 10.1021/acs.inorgchem.2c00787. Epub 2022 Jun 21.
Two new series of unsymmetrically -functionalized porphyrins, MTPP(NO)MA (), (MA = methyl acrylate) and MTPP(NO)MB () (MB = mono-benzo) (where M = 2H, Co(II), Ni(II), Cu(II) and Zn(II)), were synthesized and characterized by various spectroscopic techniques. The saddle shape conformation of ZnTPP(NO)MAPy and ZnTPP(NO)MB was confirmed by single-crystal X-ray analysis. Density functional theory (DFT) calculation revealed that NiTPP(NO)MB has a severe nonplanar geometry possessing a high magnitude of ΔC = ±0.727 Å and Δ24 = ±0.422 Å values among all other porphyrins. Synthesized -substituted porphyrins exhibited red-shifted B- and Q-bands corresponding to their parent molecule due to the electron-withdrawing peripheral substituents. Notable redshift (Δλ = 50-60 nm) in electronic spectral features and with weak-intensity emission spectral features were observed for the free-base porphyrins and Zn(II) complexes compared to HTPP and ZnTPP, respectively. The first-ring reduction potential of MTPP(NO)MA () exhibited 0.21-0.5 V anodic shift, whereas 0.18-0.23 V anodic shift was observed in the first-ring oxidation potential compared to the corresponding MTPPs due to the presence of electron-withdrawing -substituents at the periphery of the macrocycle. Interestingly, NiTPP(NO)MA () has shown an additional Ni/Ni oxidation potential observed at 2.05 V along with two ring-centered oxidations. The first-ring reduction and oxidation potentials of MTPP(NO)MB () have shown 0.39-0.46 and 0.19-0.27 V anodic shifts with respect to their corresponding MTPPs. The nonlinear optical (NLO) properties of all of the porphyrins were investigated, and the extracted nonlinear optical parameters revealed intense reverse-saturable absorption (RSA) behavior and the self-focusing behavior with positive nonlinear refractive index in the range of (0.19-1.75) × 10 m/W. Zn(II) complexes exhibited the highest two-photon absorption coefficient () and cross section (σ) of ∼95 × 10 m/W and 19.66 × 10 GM, respectively, among all of the metal complexes.
合成了两个新系列的不对称功能化卟啉，即MTPP(NO)MA（）（MA = 丙烯酸甲酯）和MTPP(NO)MB（）（MB = 单苯）（其中M = 2H、Co(II)、Ni(II)、Cu(II)和Zn(II)），并通过各种光谱技术对其进行了表征。通过单晶X射线分析证实了ZnTPP(NO)MAPy和ZnTPP(NO)MB的鞍形构象。密度泛函理论（DFT）计算表明，在所有其他卟啉中，NiTPP(NO)MB具有严重的非平面几何结构，其ΔC = ±0.727 Å和Δ24 = ±0.422 Å值的幅度很大。由于吸电子的外围取代基，合成的取代卟啉相对于其母体分子表现出红移的B带和Q带。与HTPP和ZnTPP相比，分别观察到游离碱卟啉和Zn(II)配合物在电子光谱特征上有明显的红移（Δλ = 50 - 60 nm），且发射光谱特征强度较弱。MTPP(NO)MA（）的第一环还原电位表现出0.21 - 0.5 V的阳极位移，而由于大环外围存在吸电子的取代基，与相应的MTPP相比，在第一环氧化电位中观察到0.18 - 0.23 V的阳极位移。有趣的是，NiTPP(NO)MA（）在2.05 V处显示出额外的Ni/Ni氧化电位以及两个环中心氧化。MTPP(NO)MB（）的第一环还原和氧化电位相对于其相应的MTPP分别显示出0.39 - 0.46和0.19 - 0.27 V的阳极位移。研究了所有卟啉的非线性光学（NLO）性质，提取的非线性光学参数揭示了强烈的反饱和吸收（RSA）行为以及在(0.19 - 1.75)×10 m/W范围内具有正非线性折射率的自聚焦行为。在所有金属配合物中，Zn(II)配合物分别表现出最高的双光子吸收系数（）和约95×10 m/W的截面（σ）以及19.66×10 GM。
