Mononuclear and dinuclear Re(i) complexes incorporating 1-(2-pyridylazo)-2-naphthol: synthesis, structure, spectral, DFT and TDDFT studies

Abstract

The Re(I) complexes [Re(HPAN)(CO)(3)Cl], 1, and [Re(2)(PAN)(2)(CO)(6)]·C(6)H(12), 2·C(6)H(12), have been prepared by reacting [Re(CO)(5)Cl] with HPAN. Here (PAN)(-) is the deprotonated form of 1-(2-pyridylazo)-2-naphthol. A subsequent reaction of [Re(HPAN)(CO)(3)(CF(3)SO(3))] with a chelating diphosphine ligand generates [Re(PAN)(CO)(P-P)]·CH(2)Cl(2), 3·CH(2)Cl(2). The structures of the complexes are determined by X-ray crystallography. The molecular structures observed in the solid state are retained in the solution ((1)H, (13)C and (31)P NMR and mass spectra). The photophysical and electrochemical properties are also investigated. The gas-phase geometry optimization and the electronic structures of [Re(HPAN)(CO)(3)Cl], [Re(2)(PAN)(2)(CO)(6)] and [Re(PAN)(CO)(P-P)] have been investigated with the framework of density functional theory. The absorption spectra of the complexes are calculated by time dependent density functional theory (TDDFT) using a conductor-like polarizable continuum model (CPCM). DFT calculation shows good agreement with the experimental ground state IR and NMR values. Excited state TDDFT calculations provide a better insight into the experimental luminescence spectra of all the complexes in solution.

Synthesis, structure and spectral properties of O,N,N coordinating ligands and their neutral Zn(ii) complexes: a combined experimental and theoretical study

“…Quantum yields of the complexes were determined in freeze-pump-thaw-degassed solutions of the complexes by a relative method using quinine sulfate in the same solvent as the standard. 23 The quantum yields were calculated using eqn (1), 24 where Φ r and Φ std are the quantum yields of the unknown and standard samples [Φ std = 0.54 (at 298 K) in THF at λ ex = 460 nm], A r and A std (<0.1) are the solution absorbance at the excitation wavelength (λ ex ), I r and I std are the integrated emission intensities, and η r and η std are the refractive indices of the solvent. Experimental errors in the reported luminescence quantum yields were about 10%.…”

Molecular and Electronic Structures of Complexes Containing 1-(2-pyridylazo)-2-phenanthrol (PAPL): Revisiting a Redox-Active Ligand

“…The PAPL ligand was first reported by Chiswell and co-workers in 1963, and a handful of reports over the 1970s and 1980s document the preparation and electronic spectra of first, second, and some third row transition metal–PAPL complexes. , Since the mid-1980s, the chemistry of PAPL has been largely neglected with the exception of a few patents, and to our knowledge, there is no structural data reported from X-ray diffraction experiments for any of the reported metal–PAPL complexes. Nor is there any computational work outlining the electronic structure of these complexes, and we could find only two reports focused on the electrochemical properties of cobalt–PAPL complexes and electronic spectra of metal–PAPL complexes. , In general, other PAPL-type ligands bearing other aryl substituents, such as phenol or napthol, in place of the phenanthrol ring, while known, have also not been thoroughly investigated in terms of their electronic or spectroscopic properties . Our objective was to revisit the PAPL family of complexes and explore in more detail their structural and electronic properties.…”

Non-innocent behavior of 1-(2′-pyridylazo)-2-naphtholate coordinated to polypyridine ruthenium(II) complexes

“…IR spectra were obtained in KBr pellets on a Shimadzu FTIR-8300 spectrophotometer. 1 H NMR spectra were obtained in a 5 mm NMR tube on a Varian Inova 300 MHz spectrometer in CDCl 3 or acetone-d 6 . Cyclic voltammetry measurements were carried out using a PARC system, from EG&G Instruments, consisting of a potentiostat model 283 and a three electrode cell arrangement.…”

“…These ligands constitute an important class of analytical reagents employed in spectrophotometric analysis, amperometric determination of metal ions, and as indicators in complexometric titrations [5]. Although coordination of pyridylazo and its derivatives to metals has been extensively investigated [6][7][8][9][10], there are limited number of articles that discuss reactions between pyridylazo ligands and ruthenium complexes [11,12]. In addition, there is a lack of relevant information concerning spectroscopic and electrochemical properties of these complexes.…”