Second-Order NLO Active Heterotrimetallic Schiff Base Metallopolymer

Abstract

International audienceThe new ionic heterotrimetallic unsymmetrically-substituted Schiff base complex [Ni₍eta (5)-Cp)Fe(eta (5)-C5H4)-C(=O)CH=C(4-HO-C6H4)NCH2CH2N=CH-(2-O-(eta (6)-C6H4)Ru(eta (5)-Cp*)_][PF6] (3; Cp = C5H5 and Cp* = C-5(CH3)(5)) was prepared in 86% yield by a one-pot procedure by mixing equimolar amounts of 4-hydroxyphenyl functionalized ferrocenylenaminone 1, the organometallic aldehyde [(eta (5)-Cp*)Ru(eta (6)-2-HO-C6H4CHO)][PF6] (2) and nickel(II) acetate tetrahydrate in refluxing ethanol for 2 h. Its corresponding side-chain metallopolymer 4 was synthesized by reacting the organometallic-inorganic hybrid 3 with polyacrylic acid (DP = 25) in DMF at 110 A degrees C for 48 h with an equimolar quantity of N,N'-dicyclohexylcarbodiimide and a catalytic amount of 4-dimethylaminopyridine. The new complex 3 was characterized by FT-IR and multidimensional NMR spectroscopy, elemental analysis and mass spectrometry. Single crystal X-ray diffraction analysis of 3 showed that the ferrocenyl and [(eta (5)-Cp*)Ru](+) units exhibit an anti-conformation and are almost coplanar with the unsymmetrical Schiff base complex fragment, while the 4-HO-C6H4 plane is almost perpendicular. The four-coordinate Ni-II metal ion adopts a square planar geometry, with two nitrogen and two oxygen donor atoms that are mutually trans. Size-Exclusion Chromatography established that metallopolymer 4 is formed of approximately three pendant ionic trimetallic units, while Differential Scanning Calorimetry and Thermal Gravimetric Analysis indicated that 3 and 4 are thermally stable with decomposition temperatures that exceed or border to 250 A degrees C. Harmonic Light Scattering measurements at 1.91 A mu m incident wavelength showed that compounds 3 and 4 exhibit rather high second-order nonlinear responses, with hyperpolarizability beta (1.91) values strongly increasing on passing from the monomeric unit 3 to its metallopolymeric counterpart 4

Novel Co(II), Ni(II) and Cu(II) complexes involving a 2-thienyl and trifluoromethyl containing symmetrically-substituted tetradentate Schiff-base ligand: Syntheses, structures, electrochemical and computational studies

“…The solid-state FT-IR spectra of 3a-c present similar patterns, exhibiting two strong and medium intensity bands in the 1613-1606 and 1530-1518 cm -1 ranges, respectively, attributed to ν(C … O), ν(C … C) and/or ν(C … N) stretching modes of the chelating Schiff base skeleton [14][15][16]. The disappearance of the ν(N-H) vibration observed at 3186 cm -1 in proligand 2 clearly suggests that the Schiff base is coordinated to the metal ion through the imine nitrogen atoms.…”

“…During the last years, our efforts have been focused on the synthesis of main-chain and side-chain polymers of appropriately-substituted Schiff base metal(II) complexes, exhibiting large second-order nonlinear optics (NLO) responses [14][15][16]. However, those metallopolymers suffer poor solubility leading to low grafting degrees and oligomers.…”

Stabilization of Pristine Low Resistive State in a Ruthenium(II)‐Polymer of a Hexadentate Schiff Base Ligand: Synthesis, Characterization, and Application as Non‐Volatile Memory Device

“…[36,37] Although Ru(II)-hybrid polymers have been well explored for their various applications like electro-chromic and non-volatile memristive properties, reports on hybrid Ru(II)-poly of Schiff base ligand are few. [38,39] Keeping this in mind, we synthesized and characterized Ru(II)-metal hybrid polymer of our previously reported Schiff base ligand [40] and studied its effect on non-volatile memristive behaviour. This is a first report which studies the non-volatile memory properties of Ru(II)-poly of any Schiff base ligand.…”

Synthesis, structures, electrochemical and quantum chemical investigations of Ni(ii) and Cu(ii) complexes with a tetradentate Schiff base derived from 1-(2-thienyl)-1,3-butanedione

“…[2][3][4] The versatility of Schiff base ligands arises from their structural and electronic variations, achieved by varying the stereo-electronic nature of the substituents incorporated on their skeletons via the β-diketone starting materials. 5 Those easily synthetized and easily tunable dicarbonyl building blocks, presenting a keto-enol tautomerism, [6][7][8] are readily tailored to bring about donor, acceptor, polymerizable, or electroactive groups at the three carbon atoms constituting the propane-1,3-dione skeleton. [7][8][9][10][11][12][13][14] β-diketones containing a thiophene group are of particular interest because they can be used as starting materials for the construction of Schiff base derivatives and metal complexes tagged with electroactive thiophene moieties, thus allowing electrochemical polymerization to conveniently enable the direct preparation of an insoluble polymeric coating on the surface of the electrode.…”

“…5 Those easily synthetized and easily tunable dicarbonyl building blocks, presenting a keto-enol tautomerism, [6][7][8] are readily tailored to bring about donor, acceptor, polymerizable, or electroactive groups at the three carbon atoms constituting the propane-1,3-dione skeleton. [7][8][9][10][11][12][13][14] β-diketones containing a thiophene group are of particular interest because they can be used as starting materials for the construction of Schiff base derivatives and metal complexes tagged with electroactive thiophene moieties, thus allowing electrochemical polymerization to conveniently enable the direct preparation of an insoluble polymeric coating on the surface of the electrode. [15][16][17] In this context, we have recently disclosed the generation and characterization of a polythienyl-containing β-diketonate copper(II) compound and its deposition on an electrode, upon electropolymerization of the [Cu(II)-bis-{1-(2-thienyl)-3-(3-thienyl)propane-1,3-dionato}] complex using potentiodynamic method.…”