The Primary Demonstration of Exciton Coupling Effects on Optical Limiting Properties of Blue Double‐Decker Lanthanide Phthalocyanine Salts

Abstract

In this manuscript, novel green and blue sandwich-type rareearth phthalocyanines (LnPc 2 ) are presented. This parent green LnPc 2 complex is named bis-{2(3),9(10),16(17),23(24)-tetra(4tert-buylphenoxy) phthalocyaninato} neodymium (III) (2) and modified into blue LnPc 2 complexes (3), (4) and (5) based on hexadecyltrimethylammonium ion, mononeodymium(III) diacetate and monodysprosium(III) diacetate as counter ions, respectively. These stable blue lanthanide Pc salts are highly soluble in many organic and inorganic solvents. All complexes 2, 3, 4 and 5 were studied for optical limiting for the first time using Z-scan at nanosecond regime in the visible absorption spectral wavelength (532 nm). Our studies reveal the advantage of exciton coupling in blue sandwich-type rare-earth phthalocyanines over the p-radicals (characterized by blue valence at 485 nm) in the green counterpart which are in resonance with the 532 nm wavelength for optical limiting application. Large singlet ground state to excited state absorption cross section ratios were found, particularly for complex 5 in comparison to that of complex 2.[a] Dr.

Nonlinear optical behavior of n-tuple decker phthalocyanines at the nanosecond regime: investigation of change in mechanisms

“…The absorption spectrum of complex 2 has been discussed in detail before. 39 For complexes 3a and 3b, the Q-band appeared to be more blue- shied (Fig. 2) to about 640 and 636 nm, respectively, with the complete disappearance of the BV band.…”

“…The mass of complex 2 has been reported before. 39 For complexes 3a and 3b, 4822 and 7290 amu were the expected masses, respectively. These experimentally determined masses correspond well with the structures of the complexes 3a and 3b whose theoretical masses are 4824 and 7291 amu, respectively (Fig.…”

“…The ESR bandwidth of complex 2 at 298 K is $8.01 G, which is broader than the bands of the other neodymium based phthalocyanines. 55 The ESR spectroscopy data for complex 2 was reported earlier 39 and is provided in Fig. S3.…”

“…3.2.6 X-ray diffractometry. The X-ray diffractograms of complex 2 and its corresponding thin lm (TF-2) have been reported before 39 and are shown in Fig. 3 for comparison.…”

“…The nonlinear optical parameters for complex 2 and its corresponding thin lm (TF-2) have been discussed in detail before. 39 For precise comparison of the nonlinear behavior, all the complexes were subjected to the same experimental conditions in the nanosecond regime. The establishment of the reverse saturable absorption (RSA), characterized by the reduction of T Norm at focus (z ¼ 0), was achieved upon scanning along the z-axis of the Z-scan under resonant conditions.…”