Rathi Pinki, Kumar Sandeep, Banerjee Dipanjan, Soma Venugopal Rao, Sankar Muniappan
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India.
Dalton Trans. 2020 Mar 14;49(10):3198-3208. doi: 10.1039/c9dt04252k. Epub 2020 Feb 24.
Two new series of β-triphenylamine-appended porphyrins (MTPP(TPA)X, (where M = 2H, Co(ii), Ni(ii), Cu(ii), Zn(ii) and X = NO/CHO) have been synthesized and characterized by various spectroscopic techniques, namely, UV-vis, fluorescence, NMR spectroscopy, mass spectrometry, cyclic voltammetry, density functional theory and ultrafast nonlinear optical (NLO) studies. They exhibited 16-22 nm and 39-58 nm red-shifts in the Soret and Q(0,0) bands, respectively, as compared to MTPPs due to the resonance and inductive effects of β-substituents on the porphyrin π-system. The first reduction potential of CuTPP(TPA)NO and CuTPP(TPA)CHO exhibited an anodic shift by 0.44 and 0.36 V, respectively, as referenced to CuTPP, due to the electronic nature of β-substituents (NO and CHO), which led to their easier reduction compared with CuTPP. HTPP(TPA)NO and HTPP(TPA)CHO exhibited the largest resultant dipole moments (7.66 D and 4.55 D, respectively) as compared to HTPP (0.052 D) due to the cross-polarized push-pull effect of β-substituents (NO/CHO and triphenylamino groups) and the nonplanarity of the macrocyclic core. Third-order nonlinear optical properties of MTPP(TPA)NO and MTPP(TPA)CHO (M = 2H and Zn(ii)) were investigated in a broad spectral range (680-850 nm) using the Z-scan technique with femtosecond 80 MHz pulses. These materials demonstrate strong nonlinear optical coefficients, endowing them with potential for prominent photonic applications.
已合成了两个新系列的β-三苯胺取代卟啉（MTPP(TPA)X，其中M = 2H、Co(ii)、Ni(ii)、Cu(ii)、Zn(ii)且X = NO/CHO），并通过各种光谱技术进行了表征，即紫外可见光谱、荧光光谱、核磁共振光谱、质谱、循环伏安法、密度泛函理论和超快非线性光学（NLO）研究。由于β-取代基对卟啉π体系的共振和诱导效应，与MTPPs相比，它们在Soret带和Q(0,0)带分别表现出16 - 22 nm和39 - 58 nm的红移。相对于CuTPP，CuTPP(TPA)NO和CuTPP(TPA)CHO的首次还原电位分别表现出0.44 V和0.36 V的阳极偏移，这是由于β-取代基（NO和CHO）的电子性质，导致它们比CuTPP更容易还原。与HTPP（0.052 D）相比，HTPP(TPA)NO和HTPP(TPA)CHO表现出最大的合成偶极矩（分别为7.66 D和4.55 D），这是由于β-取代基（NO/CHO和三苯胺基团）的交叉极化推挽效应以及大环核心的非平面性。使用飞秒80 MHz脉冲的Z扫描技术在宽光谱范围（680 - 850 nm）内研究了MTPP(TPA)NO和MTPP(TPA)CHO（M = 2H和Zn(ii)）的三阶非线性光学性质。这些材料表现出很强的非线性光学系数，使其具有在显著光子应用中的潜力。
