scholarly journals DFT/TD-DFT study on spectroscopic properties of zinc(II), nickel(II), and palladium(II) metal complexes with a thiourea derivative

2016 ◽  
Vol 81 (11) ◽  
pp. 1263-1272 ◽  
Author(s):  
Xin Wang ◽  
Jieqiong Li ◽  
Li Wang ◽  
Wenpeng Wu ◽  
Zheng Du ◽  
...  

The geometries, electronic structures, and spectral properties of three metal complexes Zn(C10H12N3OS)2 (1), Ni(C10H12N3OS)2 (2), and Pd(C10H12N3OS)2 (3) with N-(2-pyridinyl)morpholine-4-carbothioamide as a ligand are investigated by means of DFT (density functional theory) and TD-DFT (time-dependent density functional theory) methods. Complex 1 is a distorted tetrahedral geometry, while complexes 2 and 3 present a distorted square-planar coordination environment. In the simulated range, the spectrum of complex 1 has five obvious absorption peaks and one of them has the strongest intensity. The latter two complexes have one more absorption peak and shoulder peak with the similar intensity. Moreover, the strongest peaks of complexes 2.

2020 ◽  
Vol 98 (4) ◽  
pp. 194-203 ◽  
Author(s):  
Sefia Brahim ◽  
Houari Brahim ◽  
Stéphane Humbel ◽  
Ali Rahmouni

Detailed theoretical studies of Ni(II) complexes in a distorted square planar form and containing dithio and (P, P) chelating ligands were performed. These Ni(II) complexes are investigated for their use in dye-sensitized solar cells (DSSC). Structures and UV–vis spectra are calculated at density functional theory (DFT) and time-dependent density functional theory (TD-DFT) theories using B3LYP and CAM-B3LYP functionals and 6-31G(d,p) and 6-31G+(d) basis sets. Geometry optimizations result in excellent agreement with the experimental results. Moreover, the analysis of the frontier molecular orbitals (FMOs) allowed a detailed assignment and a clear analysis of the electronic transitions. The TD-DFT calculations reproduce the main spectroscopic properties observed and substituent effects. The results reveal that all absorption spectra are characterized by mixed character mainly dominated by metal to ligand and ligand to ligand charge transfers (MLCT and LLCT). We unveil how the substituent variations affect the DSSCs features of the complexes.


2017 ◽  
Vol 19 (43) ◽  
pp. 29068-29076 ◽  
Author(s):  
Yu-Te Chan ◽  
Ming-Kang Tsai

The CO2 reduction capabilities of transition-metal-chelated nitrogen-substituted carbon nanotube models (TM-4N2v-CNT, TM = Fe, Ru, Os, Co, Rh, Ir, Ni, Pt or Cu) are characterized by density functional theory.


2011 ◽  
Vol 8 (s1) ◽  
pp. S195-S202
Author(s):  
Y. Belhocine ◽  
M. Bencharif

The structure and spectroscopic properties of polycyclic aromatic ligands of 2,3,6,7,10,11-hexakis (alkylthio) triphenylene (alkyl: methyl, ethyl, and isopropyl; corresponding to the abbreviations of the molecules: HMTT, HETT and HiPTT) were studied using density functional theory (DFT) and time dependent density functional theory (TD-DFT) methods with triple-zeta valence polarization (TZVP) basis set. It was shown that the type of functional theory used, Becke-Perdew (BP) and Leeuwen-Baerends (LB94) implemented in Amsterdam Density functional (ADF) program package, does not have essential influence on the geometry of studied compounds in both ground and excited states. However, significant differences were obtained for the band gap values with relativistic effects of the zero order regular approximation scalar corrections (ZORA) and LB94 functional seems to reproduce better the experimental optical band gap of these systems.


Author(s):  
Claudio Garino ◽  
Luca Salassa

The use of density functional theory (DFT) and time-dependent DFT (TD-DFT) to study the photochemistry of metal complexes is becoming increasingly important among chemists. Computational methods provide unique information on the electronic nature of excited states and their atomic structure, integrating spectroscopy observations on transient species and excited-state dynamics. In this contribution, we present an overview on photochemically active transition metal complexes investigated by DFT. In particular, we discuss a representative range of systems studied up to now, which include CO- and NO-releasing inorganic and organometallic complexes, haem and haem-like complexes dissociating small diatomic molecules, photoactive anti-cancer Pt and Ru complexes, Ru polypyridyls and diphosphino Pt derivatives.


2019 ◽  
Vol 824 ◽  
pp. 204-211 ◽  
Author(s):  
Malinee Promkatkaew ◽  
Pornthip Boonsri ◽  
Supa Hannongbua

Structural and spectroscopic properties of Ruhemann’s purple (RP) and its transition metal coordination complexes were calculated using theoretical chemistry techniques. The obtained information described RP and its coordination complexes with the transition metal ions [Cr(II), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)]. The procedures involved calculations of what are called density functional theory (DFT) and time-dependent DFT (TD-DFT). These methods optimized what is called, in the codes of theoretical chemistry, the hybrid density B3LYP function employing the 6‐311++G(d,p) and LANL2DZ basis sets. The RP geometries, bond lengths, angles, quantum chemical parameters, and excitation spectra indicate that the RP is well able to coordinate with a transition element ion. Then the correlation of these theoretical results with experimental observations provides a detailed description of the structural and spectroscopic properties of RP compounds. The inclusion of solvent effects causes a blue shift in all theoretical excitation spectra. In summary, this work leads to an understanding of the characteristics of transition metal complexes with Ruhemann’s purple. These materials can be applied in forensic chemistry as reagents in developing latent fingerprints.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7783
Author(s):  
Dawid Zych

Recently, mono- and dinuclear complexes have been in the interest of scientists due to their potential application in optoelectronics. Herein, progressive theoretical investigations starting from mononuclear followed by homo- and heterometallic dinuclear osmium and/or ruthenium complexes with NCN-cyclometalating bridging ligands substituted by one or two kinds of heteroaryl groups (pyrazol-1-yl and 4-(2,2-dimethylpropyloxy)pyrid-2-yl) providing the short/long axial symmetry or asymmetry are presented. Step-by-step information about the particular part that built the mixed-metal complexes is crucial to understanding their behavior and checking the necessity of their eventual studies. Evaluation by using density functional theory (DFT) calculations allowed gaining information about the frontier orbitals, energy gaps, and physical parameters of complexes and their oxidized forms. Through time-dependent density functional theory (TD-DFT), calculations showed the optical properties, with a particular emphasis on the nature of low-energy bands. The presented results are a clear indication for other scientists in the field of chemistry and materials science.


2015 ◽  
Vol 44 (18) ◽  
pp. 8529-8542 ◽  
Author(s):  
Gunasekaran Velmurugan ◽  
Ponnambalam Venuvanalingam

The electronic structure and spectroscopic properties of a series of rhenium(i) terpyridine complexes were investigated using density functional theory (DFT) and time dependent density functional theory (TD-DFT) methods.


2019 ◽  
Author(s):  
Siham Lakrikh ◽  
Hajar Atmani ◽  
Latifa Laallam ◽  
Ahmed Jouaiti

Abstract In this work, we use theoretical methods DFT density functional theory to calculate the electronic properties of the five molecules based on N- (7-indazolyl) -aryl sulfonamides, for an example of these parameters: HOMO energies, Energies of LUMO and E gap which are very interesting in the photovoltaic field. At the same time, we explore our result to achieve our goal of treminations the electronic and spectroscopic properties of these organic molecules through the use of TD-DFT, to determine the wavelengths of the molecules and to trace the visible, ultra-violet spectrum and to determine the transition states.


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