Quantum Chemical Studies on The Prediction of Structures ...
QUANTUM CHEMICAL STUDIES ON THE PREDICTION OF STRUCTURES, CHARGE DISTRIBUTIONS AND VIBRATIONAL SPECTRA OF SOME Ni(II), Zn(II), AND Cd(II) IODIDE COMPLEXES Tayyibe Bardak, Mustafa Kumru, and Ahmet Altun stanbul/Turkey International Symposium on Molecular Spectroscopy
Conclusion Introduction In this study; ntroduction
Why anilines? Aniline and its derivatives are widely used in: electro-optical and microelectronic devices such as diodes and transistors, intermediate in the production of dyes, pharmaceuticals, ligands in coordination chemistry. Introduction
Why transition metal complexes? A transition metal complex consists of a transition metal coordinated to one or more ligands. Good in catalysis, materials synthesis, photochemistry, and biological systems. Display diverse chemical, optical and magnetic properties. Effective in combining with other elements.
Introductio n Complex Geometries Computations Quantum chemical calculations were carried out with Gaussian 03 software package on our linux server cluster.
The structures and normal modes were visualized by Gausview. Calculations were performed in the gas phase at B3LYP/def2-TZVP level. Def2-TZVP basis set was downloaded from EMSL Basis Set Library, and used with GEN keyword in Gaussian 03. Effective core potentials (ECP) were used within the def2-TZVP. 1. Molecular Structures 2. Mulliken, NBO and APT Charge Analysis
3. Vibrational Analysis Results Molecular structures of the free ligands Mean absolute errors (MAE) and linear correlation coefficient (R2) values:
Bond lengths: 0.015 and 0.984 for p-toludine & 0.016 and 0.983 for m-toluidine. Bond angles: 1.164 and 0.926 for p-toluidine & 1.300 and 0.913 for m-toluidine. Results Molecular structures of the metal iodide complexes of p-toluidine
Distorted tetrahedral Distorted polymeric octahedral Results Some geometry parameters of the metal iodide complexes of p-toluidine
B3LYP/def2-TZVP level predicts: C-N bond length in free p-toluidine: 1.397 H-N-H angle in free p-toluidine: 111.9o Results Molecular structures of the metal iodide complexes of m-toluidine
Distorted polymeric octahedral Distorted tetrahedral Results Some geometry parameters of the metal iodide
complexes of m-toluidine B3LYP/def2-TZVP level predicts: C-N bond length in free m-toluidine: 1.394 H-N-H angle in free m-toluidine: 112.2o Resul ts
Charge Distributions Mulliken, natural bond orbital (NBO), and atomic polar tensor (APT) charge analyses are performed for all compounds. Mulliken is one of the traditional and most widely used methods. But, it is basis set dependent and thus have weaknesses in predicting inaccurate results at some basis sets. Natural charges provided by the NBO method are based on the investigation of the atomic and molecular orbitals and mostly give good results, having no basis set dependency. APT charges are based on the parametrization of the experimental infrared intensities, and
can be directly obtained from default vibrational frequency calculations. If the observed infrared frequencies are consistent with the computed frequencies, mostly APT charge results are also accurate. Resul ts Charge distribution of the free ligands
In free ligands, charge distributions are mostly in agreement with three of the methods, having small differences. Resul Charge distribution of the Ni(II) iodide complexes of pts toluidine and m-toluidine Resul
Charge distribution of the Cd(II) iodide complexes of pts toluidine and m-toluidine Resul ts Charge distribution of the Zn(II) iodide complexes of p-toluidine and mtoluidine Result
s Charge Results In our previous studies, we have also calculated some metal bromide complexes. Different from the metal bromide complexes, we have obtained inaccurate results for charge distributions of metal iodide complexes in the NBO analysis. The reason for this may be iodine is heavier than bromine, and located in the lower part of the periodic table having large number of core electrons. Since
effective core potential (ECP) is used for the iodine containing systems at def2-TZVP level, it may be affected our natural charge distribution results negatively. Results VIBRATIONAL FREQUENCIES As an evidence of complex formation between metal halides and ligands some modes originating from ligand show substantial shifts in the spectra of
complexes. Amino group frequencies of the ligands are generally more affected from the coordination, which shows the complex formation occurs via nitrogen atom of the free ligand. Results Vibrational Frequencies of the Metal Iodide Complexes of P-toluidine
Results Vibrational Frequencies of the Metal Iodide Complexes of M-toluidine Conclusions 1. Molecular Structures Zinc and cadmium complexes are found to have distorted
tetrahedral structures. Nickel complexes have octahedral coordination around the Ni atom, by sharing two I atoms of the neighboring complexes. Conclusions 2. Charge Analysis NBO results are not reliable for our metal iodide complexes.
In terms of having physically most meaningful results, APT method is more trustworthy by showing the most positive charges on metal atoms, and the most negative charges on the nitrogen atoms and halogens. Conclusions 3. Vibrational Analysis As an evidence of complex formation between metal (II) halides and the ligands, amino group frequencies shift lower or higher wavenumbers, which
show coordination occurs via nitrogen atom of the free ligands. In the vibrational spectra of experimental only studies some assignments were not determined correctly. However, we provide a full vibrational assignment of the title complexes for the first time, by means of density functional calculations. Density functional theory finds a good compromise in terms of accuracy and the computational cost. However, for the vibrational frequencies the results might be better, especially above 1700 cm-1.
The development of the new functionals and basis sets for the transition metal complexes is essential as well as providing background information for different systems with the available functionals and basis sets. The results of the present study will be able to serve as a reference for future theoretical studies, which allows molecular dynamics simulation of transition metal complexes or transition metal based drugs. Our Related Articles Tayyibe Bardak, Mustafa Kumru, Ahmet Altun, Molecular structures, charge distributions, and vibrational
analyses of the tetracoordinate Cu(II), Zn(II), Cd(II), and Hg(II) bromide complexes of p-toluidine investigated by density functional theory in comparison with experiments., Journal of Molecular Structure, Vol. 1116, pp. 292-302, 2016. Tayyibe Bardak, Ahmet Altun, Kurtulu Glck, Mustafa Kumru Synthesis, structural, spectral (FT-IR, FT-Ra and UV-Vis), thermal and density functional studies on p-methylaniline complexes of Mn(II), Co(II), and Ni(II) bromides, Journal of Molecular Structure, Vol. 1100, pp.475-485, 2015. Mustafa Kumru, Tayyibe Bardak, Sadk Gner, "DFT calculations and experimental FT-IR, dispersive-Raman and EPR spectral studies of Copper (II) chloride complex with 3-amino-1-methylbenzene", Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Vol. 123, pp.187-193, 2014.
Tayyibe Bardak, Mustafa Kumru, Sadk Gner, "Molecular structure, vibrational and EPR spectra of Cu(II) chloride complex of 4-amino-1-methylbenzene combined with quantum chemical calculations", Journal of Molecular Structure, Vol. 1054-1055, pp.76-82, 2013. Thank You! Source: http://www.sae.edu/tur/tr/campuses/istanbul stanbul/Turkey
Reviewing types of slope. ... No slope Undefined slope. The slope of a line. The slope of a nonvertical line passing thru the points (x 1,y 1) (x 2,y 2) : Author: Miller, Kelly Created Date: 08/26/2015 12:30:33 Title: Slope...
Career Portfolio How to Present Yourself to Potential Employers Presented by April Legler, Lecturer of Career Education, KSOB What is a Portfolio? What is your understanding of a portfolio and its purpose? Who has traditionally created portfolios? Does anyone have...
Chapter 1Introduction to Economics. 1.1 What is Economics? 1.2 The Language of Economics. 1.3 What is a Market? 1.4 The Circular Flow of Income. 1.5 The Economic Problem. 1.6 The Production Possibility Frontier. 1.7 Economic Systems. Apply Economic Principles to...
A summary of your professional, personal experiences and skills relevant to the position you are seeking. A reflection of your education, accomplishments, volunteer and community activities. Resumes and CV's are designed to assist in getting the interview, not the residency...
Gifted and Talented at Garden Oaks Montessori Magnet. ... The best preparation for taking any achievement test is concentrated effort related to classroom activities, completion of homework, engaging in activities beyond assigned homework, and undertaking a wide variety of projects...
Know Your IBM (KYI) Week 1 Stay up to date on IBM news! Access the PartnerWorld news page to see what is available and subscribe to the news features that meet your needs. PartnerWorld Communication Week 1 Access the 10...
Facilitate adoption and stickiness of Cisco technologies - Identity, EnergyWise, Stack Power, Smart Install, Auto Smartports. Ease-of-Use and Ease-of-Operations. Significantly address #1 customer issue with LMS - usability. Context & Relevance. Extensible framework to leverage Cisco's solutions and best practices...
Chapter 4 is the final introductory chapter. It deals with network management, with a strong focus on network design. Subsequent chapters will apply the concepts in these four introductory chapters to specific situations, including wired switched and wireless LANs and...
Ready to download the document? Go ahead and hit continue!