Density functional computations of99Ru chemical shifts: relativistic effects, influence of the density functional, and study of solvent effects onfac—[Ru(CO)3I3]−

2006 ◽  
Vol 44 (11) ◽  
pp. 989-1007 ◽  
Author(s):  
Jochen Autschbach ◽  
Shaohui Zheng
Keyword(s):  
Solvent Effects ◽  
Density Functional ◽  
Chemical Shifts ◽  
Relativistic Effects ◽  
Density Functional Computations

[Pt@Pb12]2– — A challenging system for relativistic density functional theory calculations of 195Pt and 207Pb NMR parameters

2011 ◽  
Vol 89 (7) ◽  
pp. 814-821 ◽  
Author(s):  
Boris Le Guennic ◽  
Jochen Autschbach
Keyword(s):  
Density Functional ◽  
Chemical Shifts ◽  
Relativistic Effects ◽  
Magnetic Coupling ◽  
Principal Component ◽  
Density Functional Theory Calculations ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Test Case ◽  
Nmr Parameters

We report computations of NMR chemical shifts and indirect spin-spin coupling constants (J couplings) for the [Pt@Pb12]2– “superatom”. The system is strongly influenced by relativistic effects. The Pt–Pb coupling constant is predicted to be negative, with its magnitude being in reasonable agreement with experiment. Pt and Pb chemical shifts also agree reasonably well with experiment. The Pb shielding tensor is strongly anisotropic, with a large deshielding principal component dominated by magnetic coupling between frontier orbitals of the cluster that resemble atomic g orbitals. The NMR parameters are sensitive to approximations made in the computations and require the inclusion of spin-orbit coupling in the theoretical model to achieve reliable results. Computing the NMR parameters of the compact [Pt@Pb12]2– system with its many electrons proves to be a challenging test case for relativistic density functional methods.

scholarly journals RELATIVISTIC EFFECTS IN THE NMR PARAMETERS OF AMINO CHLORIDE PLATINUM COMPLEXES

2020 ◽  
Vol 2020 (1) ◽  
pp. 87-92
Author(s):  
Leonid Krivdin ◽  
Valentin Semenov ◽  
Dmitriy Samul'cev
Keyword(s):  
Density Functional ◽  
Chemical Shifts ◽  
Relativistic Effects ◽  
Platinum Complexes ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Chloride Complexes ◽  
Spin Coupling Constants ◽  
High Level ◽  
Spin Spin Coupling

Relativistic effects in geometric parameters, NMR chemical shifts, and spin-spin coupling constants involving 1H, 15N, and 195Pt nuclei in cisplatin and transplatin, the simplest representatives of the platinum amino chloride complexes, were studied by means of the high-level nonempirical calculations within the framework of the Density Functional Theory

Synthesis, Conformational Analysis and Crystal Structure of New Thioxo, Oxo, Seleno Diastereomeric Cyclophosphamides Containing 1,3,2-dioxaphosphorinane

2019 ◽  
Vol 23 (2) ◽  
pp. 205-213
Author(s):  
Dorra Kanzari-Mnallah ◽  
Med L. Efrit ◽  
Jiří Pavlíček ◽  
Frédéric Vellieux ◽  
Habib Boughzala ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Density Functional ◽  
Chemical Shifts ◽  
Structural Determination ◽  
Conformational Study ◽  
Functional Theory ◽  
One Step ◽  
High Resolution Mass Spectroscopy ◽  
Resolution Mass

Thioxo, Oxo and Seleno diastereomeric cyclophosphamides containing 1,3,2- dioxaphosphorinane are prepared by a one-step chemical reaction. Their structural determination is carried out by means of Nuclear Magnetic Resonance NMR (31P, 1 H, 13C) and High-Resolution Mass Spectroscopy (HRMS). The conformational study of diastereomeric products is described. Density Functional Theory (DFT) calculations allowed the identification of preferred conformations. Experimental and calculated 31P, 13C, 1H NMR chemical shifts are compared. The molecular structure of the 2-Benzylamino-5-methyl-5- propyl-2-oxo-1,3,2-dioxaphosphorinane (3d) has been determined by means of crystal Xray diffraction methods.

Introduction to Relativistic Quantum Chemistry

2007 ◽  
Author(s):  
Kenneth G. Dyall ◽  
Knut Faegri
Keyword(s):  
Dirac Equation ◽  
Quantum Chemistry ◽  
Relativistic Theory ◽  
Density Functional ◽  
Relativistic Quantum ◽  
Relativistic Effects ◽  
Basis Sets ◽  
Spin Orbit ◽  
Approximate Methods ◽  
Nonrelativistic Theory

This book provides an introduction to the essentials of relativistic effects in quantum chemistry, and a reference work that collects all the major developments in this field. It is designed for the graduate student and the computational chemist with a good background in nonrelativistic theory. In addition to explaining the necessary theory in detail, at a level that the non-expert and the student should readily be able to follow, the book discusses the implementation of the theory and practicalities of its use in calculations. After a brief introduction to classical relativity and electromagnetism, the Dirac equation is presented, and its symmetry, atomic solutions, and interpretation are explored. Four-component molecular methods are then developed: self-consistent field theory and the use of basis sets, double-group and time-reversal symmetry, correlation methods, molecular properties, and an overview of relativistic density functional theory. The emphases in this section are on the basics of relativistic theory and how relativistic theory differs from nonrelativistic theory. Approximate methods are treated next, starting with spin separation in the Dirac equation, and proceeding to the Foldy-Wouthuysen, Douglas-Kroll, and related transformations, Breit-Pauli and direct perturbation theory, regular approximations, matrix approximations, and pseudopotential and model potential methods. For each of these approximations, one-electron operators and many-electron methods are developed, spin-free and spin-orbit operators are presented, and the calculation of electric and magnetic properties is discussed. The treatment of spin-orbit effects with correlation rounds off the presentation of approximate methods. The book concludes with a discussion of the qualitative changes in the picture of structure and bonding that arise from the inclusion of relativity.

scholarly journals First Attempts of the Use of 195Pt NMR of Phenylbenzothiazole Complexes as Spectroscopic Technique for the Cancer Diagnosis

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3970 ◽  
Author(s):  
Bruna T. L. Pereira ◽  
Mateus A. Gonçalves ◽  
Daiana T. Mancini ◽  
Kamil Kuca ◽  
Teodorico C. Ramalho
Keyword(s):  
Cancer Treatment ◽  
Cancer Diagnosis ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chloride Ion ◽  
Platinum Complexes ◽  
Dft Method ◽  
Ion Concentration ◽  
Implicit Solvent ◽  
Early Cancer Diagnosis

Platinum complexes have been studied for cancer treatment for several decades. Furthermore, another important platinum characteristic is related to its chemical shifts, in which some studies have shown that the 195Pt chemical shifts are very sensitive to the environment, coordination sphere, and oxidation state. Based on this relevant feature, Pt complexes can be proposed as potential probes for NMR spectroscopy, as the chemical shifts values will be different in different tissues (healthy and damaged) Therefore, in this paper, the main goal was to investigate the behavior of Pt chemical shifts in the different environments. Calculations were carried out in vacuum, implicit solvent, and inside the active site of P13K enzyme, which is related with breast cancer, using the density functional theory (DFT) method. Moreover, the investigation of platinum complexes with a selective moiety can contribute to early cancer diagnosis. Accordingly, the Pt complexes selected for this study presented a selective moiety, the 2-(4′aminophenyl)benzothiazole derivative. More specifically, two Pt complexes were used herein: One containing chlorine ligands and one containing water in place of chlorine. Some studies have shown that platinum complexes coordinated to chlorine atoms may suffer hydrolyses inside the cell due to the low chloride ion concentration. Thus, the same calculations were performed for both complexes. The results showed that both complexes presented different chemical shift values in the different proposed environments. Therefore, this paper shows that platinum complexes can be a potential probe in biological systems, and they should be studied not only for cancer treatment, but also for diagnosis.

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