Preparation and photoluminescent characteristics of green Tb(III) complexes with β-diketones and N donor auxiliary ligands

Abstract From the apocalyptic era of antibiotic resistance, the scientific community around the world is engaged in designing and developing metal-based compounds to inhibit and control continuously rising microbial infections. Metal based triazole-derived compounds are being explored for antimicrobial actions and potentially applicable to provide effective and nontoxic drug candidates having preferred and improved pharmacological activity. Updating the existing literature supporting such details, this review combines the chemistry, synthetic aspects of formation of triazole Schiff bases, mechanism of bioactivity of metal complexes accompanied by the assessment of the biological efficacy including antibacterial, antifungal, enzyme inhibition and antioxidant activity. This review covers bioactive symmetrical and assymmetrical mono and bis-Schiff bases synthesized from condensation involving the amine group of 3-amino-1,2,4-triazole and 3,5-diamino-1,2,4-triazole with the carbonyl group of several aromatic aldehydes and ketones along with their transition metal complexes which were characterized by physical, spectral and chemical properties. In most of the studies highlighting the biomedical assessment of imine functionalized compounds, metal complexes showed outstanding results in comparison to free ligands. Graphical Abstract

A review on the biomedical efficacy of transition metal triazole compounds

Luminous lanthanide diketonates: Review on synthesis and optoelectronic characterizations

A series of Ln3+-metal centered complexes, Ln(TTA)3(DPPI) (Ln = La, 1; Ln = Eu, 2; Ln = Tb, 3; or Ln = Gd, 4) [(DPPI = N-(4-(1H-imidazo [4,5-f][1,10]phenanthrolin-2-yl)phenyl)-N-phenylbenzenamine) and (TTA = 2-Thenoyltrifluoroacetone)] have been synthesized and characterized. Among which, the Eu3+-complex shows efficient purity red luminescence in dimethylsulfoxide (DMSO) solution, with a Commission International De L’ Eclairage (CIE) coordinate at x = 0.638, y = 0.323 and ΦEuL = 38.9%. Interestingly, increasing the amounts of triethylamine (TEA) in the solution regulates the energy transfer between the ligand and the Eu3+-metal center, which further leads to the luminescence color changing from red to white, and then bluish-green depending on the different excitation wavelengths. Based on this, we have designed the IMPLICATION logic gate for TEA recognition by applying the amounts of TEA and the excitation wavelengths as the dual input signal, which makes this Eu3+-complex a promising candidate for TEA-sensing optical sensors.

Visual Detection of Triethylamine and a Dual Input/Output Logic Gate Based on a Eu3+-Complex

Unexpected synthesis of benzimidazole from Schiff base mediated by lanthanide chloride and citotoxic activities

Characterizations and photo-physical properties of synthesized Europium(III) and Terbium(III) complexes with mercapto-triazole Schiff base ligands

Europium(III) and Terbium(III) complexes of type [Eu(L)Cl(H2O)2] and [Tb(L)OAc(H2O)2] (H2L =\nthiosemicarbazone ligands derived from substituted thiosemicarbazide and benzil/diacetyl) were synthesized. The ligands and synthesized complexes were characterized on the basis of elemental analysis, FT-IR and 1H NMR and X-ray diffraction studies. Photo-physical properties such as excitation spectra, emission spectra and luminescence curves of complexes were investigated. The most intense peak of Eu3+ ion found at 618 nm attributed to 5D0 → 7F2 transition and peak of Tb3+ ion at 549 nm\nattributed to 5D4 →7F5 transition.

Ananya Vishwakarma

Papers

Characterizations and photo-physical properties of synthesized Europium(III) and Terbium(III) complexes with mercapto-triazole Schiff base ligands

Synthesis, Characterization and Photo-Physical Properties ofEuropium(III) and Terbium(III) Complexes with Thiosemicarbazones