1
|
Batista PR, Ducati LC, Autschbach J. Dynamic and relativistic effects on Pt-Pt indirect spin-spin coupling in aqueous solution studied by ab initio molecular dynamics and two- vs four-component density functional NMR calculations. J Chem Phys 2024; 160:114307. [PMID: 38497474 DOI: 10.1063/5.0196853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 02/22/2024] [Indexed: 03/19/2024] Open
Abstract
Treating 195Pt nuclear magnetic resonance parameters in solution remains a considerable challenge from a quantum chemistry point of view, requiring a high level of theory that simultaneously takes into account the relativistic effects, the dynamic treatment of the solvent-solute system, and the dynamic electron correlation. A combination of Car-Parrinello molecular dynamics (CPMD) and relativistic calculations based on two-component zeroth order regular approximation spin-orbit Kohn-Sham (2c-ZKS) and four-component Dirac-Kohn-Sham (4c-DKS) Hamiltonians is performed to address the solvent effect (water) on the conformational changes and JPtPt1 coupling. A series of bridged PtIII dinuclear complexes [L1-Pt2(NH3)4(Am)2-L2]n+ (Am = α-pyrrolidonate and pivalamidate; L = H2O, Cl-, and Br-) are studied. The computed Pt-Pt coupling is strongly dependent on the conformational dynamics of the complexes, which, in turn, is correlated with the trans influence among axial ligands and with the angle N-C-O from the bridging ligands. The J-coupling is decomposed in terms of dynamic contributions. The decomposition reveals that the vibrational and explicit solvation contributions reduce JPtPt1 of diaquo complexes (L1 = L2 = H2O) in comparison to the static gas-phase magnitude, whereas the implicit solvation and bulk contributions correspond to an increase in JPtPt1 in dihalo (L1 = L2 = X-) and aquahalo (L1 = H2O; L2 = X-) complexes. Relativistic treatment combined with CPMD shows that the 2c-ZKS Hamiltonian performs as well as 4c-DKS for the JPtPt1 coupling.
Collapse
Affiliation(s)
- Patrick R Batista
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 São Paulo, SP, Brazil
| | - Lucas C Ducati
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 São Paulo, SP, Brazil
| | - Jochen Autschbach
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, USA
| |
Collapse
|
2
|
Predicting Pt-195 NMR Chemical Shift and 1J(195Pt-31P) Coupling Constant for Pt(0) Complexes Using the NMR-DKH Basis Sets. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7110148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pt(0) complexes have been widely used as catalysts for important reactions, such as the hydrosilylation of olefins. In this context, nuclear magnetic resonance (NMR) spectroscopy plays an important role in characterising of new structures and elucidating reaction mechanisms. In particular, the Pt-195 NMR is fundamental, as it is very sensitive to the ligand type and the oxidation state of the metal. In the present study, quantum mechanics computational schemes are proposed for the theoretical prediction of the Pt-195 NMR chemical shift and 1J(195Pt–31P) in Pt(0) complexes. The protocols were constructed using the B3LYP/LANL2DZ/def2-SVP/IEF-PCM(UFF) level for geometry optimization and the GIAO-PBE/NMR-DKH/IEF-PCM(UFF) level for NMR calculation. The NMR fundamental quantities were then scaled by empirical procedures using linear correlations. For a set of 30 Pt(0) complexes, the results showed a mean absolute deviation (MAD) and mean relative deviation (MRD) of only 107 ppm and 2.3%, respectively, for the Pt-195 NMR chemical shift. When the coupling constant is taken into account, the MAD and MRD for a set of 33 coupling constants in 26 Pt(0) complexes were of 127 Hz and 3.3%, respectively. In addition, the models were validated for a group of 17 Pt(0) complexes not included in the original group that had MAD/MRD of 92 ppm/1.7% for the Pt-195 NMR chemical shift and 146 Hz/3.6% for the 1J(195Pt–31P).
Collapse
|
3
|
Batista PR, Ducati LC, Autschbach J. Solvent effect on the 195Pt NMR properties in pyridonate-bridged Pt III dinuclear complex derivatives investigated by ab initio molecular dynamics and localized orbital analysis. Phys Chem Chem Phys 2021; 23:12864-12880. [PMID: 34075921 DOI: 10.1039/d0cp05849a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An ab initio molecular dynamics investigation of the solvent effect (water) on the structural parameters, 195Pt NMR spin-spin coupling constants (SSCCs) and chemical shifts of a series of pyridonate-bridged PtIII dinuclear complexes is performed using Kohn-Sham (KS) Car-Parrinello molecular dynamics (CPMD) and relativistic hybrid KS NMR calculations. The indirect solvent effect (via structural changes) has a dramatic effect on the 1JPtPt SSCCs. The complexes exhibit a strong trans influence in solution, where the Pt-Pt bond lengthens with increasing axial ligand σ-donor strength. In the diaqua complex, where the solvent effect is more pronounced, the SSCCs averaged for CPMD configurations with explicit plus implicit solvation agree much better with the experimental data, while the calculations for static geometry and CPMD unsolvated configurations show large deviations with respect to experiment. The combination of CPMD with hybrid KS NMR calculations provides a much more realistic computational model that reproduces the large magnitudes of 1JPtPt and 195Pt chemical shifts. An analysis of 1JPtPt in terms of localized and canonical orbitals shows that the SSCCs are driven by changes in the s-character of the natural atomic orbitals of Pt atoms, which affect the 'Fermi contact' mechanism.
Collapse
Affiliation(s)
- Patrick R Batista
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000, São Paulo, SP, Brazil.
| | | | | |
Collapse
|
4
|
Glent-Madsen I, Reinholdt A, Bendix J, Sauer SPA. Importance of Relativistic Effects for Carbon as an NMR Reporter Nucleus in Carbide-Bridged [RuCPt] Complexes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Iben Glent-Madsen
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Anders Reinholdt
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | | |
Collapse
|
5
|
Mazurek AH, Szeleszczuk Ł, Pisklak DM. A Review on Combination of Ab Initio Molecular Dynamics and NMR Parameters Calculations. Int J Mol Sci 2021; 22:4378. [PMID: 33922192 PMCID: PMC8122754 DOI: 10.3390/ijms22094378] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/17/2021] [Accepted: 04/20/2021] [Indexed: 01/19/2023] Open
Abstract
This review focuses on a combination of ab initio molecular dynamics (aiMD) and NMR parameters calculations using quantum mechanical methods. The advantages of such an approach in comparison to the commonly applied computations for the structures optimized at 0 K are presented. This article was designed as a convenient overview of the applied parameters such as the aiMD type, DFT functional, time step, or total simulation time, as well as examples of previously studied systems. From the analysis of the published works describing the applications of such combinations, it was concluded that including fast, small-amplitude motions through aiMD has a noticeable effect on the accuracy of NMR parameters calculations.
Collapse
Affiliation(s)
- Anna Helena Mazurek
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Doctoral School, Medical University of Warsaw, Banacha 1 Str., 02-093 Warsaw, Poland;
| | - Łukasz Szeleszczuk
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 Str., 02-093 Warsaw, Poland;
| | - Dariusz Maciej Pisklak
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 Str., 02-093 Warsaw, Poland;
| |
Collapse
|
6
|
Hirakawa T, Bowler DR, Miyazaki T, Morikawa Y, Truflandier LA. Blue moon ensemble simulation of aquation free energy profiles applied to mono and bifunctional platinum anticancer drugs. J Comput Chem 2020; 41:1973-1984. [DOI: 10.1002/jcc.26367] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/21/2020] [Accepted: 06/01/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Teruo Hirakawa
- Department of Precision EngineeringGraduate School of Engineering, Osaka University Suita Osaka Japan
- Institut des Sciences Moléculaires (ISM), Université Bordeaux Talence Cedex France
| | - David R. Bowler
- Department of Physics & AstronomyUniversity College London (UCL) London United Kingdom
- London Centre for Nanotechnology, UCL London United Kingdom
- International Centre for Materials Nanoarchitechtonics (WPI‐MANA), National Institute for Materials Science (NIMS) Tsukuba Ibaraki Japan
| | - Tsuyoshi Miyazaki
- International Centre for Materials Nanoarchitechtonics (WPI‐MANA), National Institute for Materials Science (NIMS) Tsukuba Ibaraki Japan
| | - Yoshitada Morikawa
- Department of Precision EngineeringGraduate School of Engineering, Osaka University Suita Osaka Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University Kyoto Japan
- Research Center for Ultra‐Precision Science and TechnologyGraduate School of Engineering, Osaka University Suita Osaka Japan
| | - Lionel A. Truflandier
- Department of Precision EngineeringGraduate School of Engineering, Osaka University Suita Osaka Japan
- Institut des Sciences Moléculaires (ISM), Université Bordeaux Talence Cedex France
| |
Collapse
|
7
|
Carvalho J, Paschoal D, Fonseca Guerra C, Dos Santos H. Nonrelativistic protocol for calculating the 1J(195Pt-15N) coupling constant in Pt(II)-complexes using all-electron Gaussian basis-set. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137279] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
8
|
Ducati LC, Marchenko A, Autschbach J. NMR J-Coupling Constants of Tl–Pt Bonded Metal Complexes in Aqueous Solution: Ab Initio Molecular Dynamics and Localized Orbital Analysis. Inorg Chem 2016; 55:12011-12023. [DOI: 10.1021/acs.inorgchem.6b02180] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lucas C. Ducati
- Department
of Fundamental Chemistry Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP 05508-000, Brazil
| | - Alex Marchenko
- Department of Chemistry University at Buffalo State, University of New York, Buffalo, New York 14260-3000, United States
| | - Jochen Autschbach
- Department of Chemistry University at Buffalo State, University of New York, Buffalo, New York 14260-3000, United States
| |
Collapse
|
9
|
Giménez CA, Maldonado AF, Aucar GA. Relativistic and electron correlation effects on NMR J-coupling of Sn and Pb containing molecules. Theor Chem Acc 2016. [DOI: 10.1007/s00214-016-1952-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
10
|
Kroutil O, Předota M, Chval Z. Pt···H Nonclassical Interaction in Water-Dissolved Pt(II) Complexes: Coaction of Electronic Effects with Solvent-Assisted Stabilization. Inorg Chem 2016; 55:3252-64. [DOI: 10.1021/acs.inorgchem.5b02261] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Ondřej Kroutil
- Institute of Laboratory Diagnostics and Public Health,
Faculty of Health and Social Studies, University of South Bohemia, J.
Boreckého 27, 37011 České Budějovice, Czech Republic
- Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - Milan Předota
- Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - Zdeněk Chval
- Institute of Laboratory Diagnostics and Public Health,
Faculty of Health and Social Studies, University of South Bohemia, J.
Boreckého 27, 37011 České Budějovice, Czech Republic
| |
Collapse
|
11
|
Melchior A, Tolazzi M, Martínez JM, Pappalardo RR, Sánchez Marcos E. Hydration of Two Cisplatin Aqua-Derivatives Studied by Quantum Mechanics and Molecular Dynamics Simulations. J Chem Theory Comput 2015; 11:1735-44. [DOI: 10.1021/ct500975a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Andrea Melchior
- Department
of Environmental and Physical Chemistry, University of Udine, 33100 Udine, Udine, Italy
| | - Marilena Tolazzi
- Department
of Environmental and Physical Chemistry, University of Udine, 33100 Udine, Udine, Italy
| | - José Manuel Martínez
- Department
of Physical Chemistry, University of Seville, 41012 Seville, Seville, Spain
| | - Rafael R. Pappalardo
- Department
of Physical Chemistry, University of Seville, 41012 Seville, Seville, Spain
| | | |
Collapse
|
12
|
Nordheider A, Hupf E, Chalmers BA, Knight FR, Bühl M, Mebs S, Chęcińska L, Lork E, Camacho PS, Ashbrook SE, Athukorala Arachchige KS, Cordes DB, Slawin AMZ, Beckmann J, Woollins JD. Peri-Substituted Phosphorus–Tellurium Systems–An Experimental and Theoretical Investigation of the P···Te through-Space Interaction. Inorg Chem 2015; 54:2435-46. [DOI: 10.1021/ic503056z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Andreas Nordheider
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| | - Emanuel Hupf
- Institut
für Anorganische Chemie, Universität Bremen, Leobener Straße, 28359 Bremen, Germany
| | - Brian A. Chalmers
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| | - Fergus R. Knight
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| | - Michael Bühl
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| | - Stefan Mebs
- Institut
für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße
36a, 14195 Berlin, Germany
| | - Lilianna Chęcińska
- Department
of Theoretical and Structural Chemistry, University of Lodz, Pomorska 163/165, 90-236 Lodz, Poland
| | - Enno Lork
- Institut
für Anorganische Chemie, Universität Bremen, Leobener Straße, 28359 Bremen, Germany
| | - Paula Sanz Camacho
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| | - Sharon E. Ashbrook
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| | | | - David B. Cordes
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| | | | - Jens Beckmann
- Institut
für Anorganische Chemie, Universität Bremen, Leobener Straße, 28359 Bremen, Germany
| | - J. Derek Woollins
- EaStChem
School of Chemistry, University of St. Andrews, Fife KY16 9ST, St Andrews, U.K
| |
Collapse
|
13
|
|
14
|
Götz AW, Autschbach J, Visscher L. Calculation of nuclear spin-spin coupling constants using frozen density embedding. J Chem Phys 2014; 140:104107. [DOI: 10.1063/1.4864053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
15
|
Lucier BEG, Johnston KE, Xu W, Hanson JC, Senanayake SD, Yao S, Bourassa MW, Srebro M, Autschbach J, Schurko RW. Unravelling the Structure of Magnus’ Pink Salt. J Am Chem Soc 2014; 136:1333-51. [DOI: 10.1021/ja4076277] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bryan E. G. Lucier
- Department
of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
| | - Karen E. Johnston
- Department
of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
| | - Wenqian Xu
- Department
of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Jonathan C. Hanson
- Department
of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Sanjaya D. Senanayake
- Department
of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Siyu Yao
- Center for Computational Science & Engineering, and PKU Green Chemistry Centre, Peking University, Beijing 100871, China
| | - Megan W. Bourassa
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Monika Srebro
- Department
of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
- Department
of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, 30-060 Krakow, Poland
| | - Jochen Autschbach
- Department
of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
| | - Robert W. Schurko
- Department
of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
| |
Collapse
|
16
|
Badu S, Truflandier L, Autschbach J. Quadrupolar NMR Spin Relaxation Calculated Using Ab Initio Molecular Dynamics: Group 1 and Group 17 Ions in Aqueous Solution. J Chem Theory Comput 2013; 9:4074-86. [PMID: 26592401 DOI: 10.1021/ct400419s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Electric field gradient (EFG) fluctuations for the monoatomic ions (7)Li(+), (23)Na(+), (35)Cl(-), (81)Br(-), and (127)I(-) in aqueous solution are studied using Car-Parrinello ab initio molecular dynamics (aiMD) simulations based on density functional theory. EFG calculations are typically performed with 1024 ion-solvent configurations from the aiMD simulation, using the Zeroth Order Regular Approximation (ZORA) relativistic Hamiltonian. Autocorrelation functions for the spherical EFG tensor elements are computed, transformed into the corresponding spectral densities (under the extreme narrowing condition), and subsequently converted into NMR quadrupolar relaxation rates for the ions. The relaxation rates are compared with experimental data. The order of magnitude is correctly predicted by the simulations. The computational protocol is tested in detail for (81)Br(-).
Collapse
Affiliation(s)
- Shyam Badu
- Department of Chemistry, University at Buffalo-State University of New York , Buffalo, New York 14260-3000, United States
| | - Lionel Truflandier
- Institut des Sciences Moléculaires, Université Bordeaux I , 351 Cours de la Libration, 33405 Talence, France
| | - Jochen Autschbach
- Department of Chemistry, University at Buffalo-State University of New York , Buffalo, New York 14260-3000, United States
| |
Collapse
|
17
|
Ortuño MA, Vidossich P, Ujaque G, Conejero S, Lledós A. Solution dynamics of agostic interactions in T-shaped Pt(ii) complexes from ab initio molecular dynamics simulations. Dalton Trans 2013; 42:12165-72. [DOI: 10.1039/c3dt50761k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Sutter K, Autschbach J. Computational study and molecular orbital analysis of NMR shielding, spin-spin coupling, and electric field gradients of azido platinum complexes. J Am Chem Soc 2012; 134:13374-85. [PMID: 22794134 DOI: 10.1021/ja3040762] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
(195)Pt, (14)N, and (15)N NMR data for five azido (N(3)(-)) complexes are studied using relativistic density functional theory (DFT). Good agreement with experiment is obtained for Pt and N chemical shifts as well as Pt-N J-coupling constants. Calculated (14)N electric field gradients (EFGs) reflect experimentally observed trends for the line broadening of azido (14)N NMR signals. A localized molecular orbital analysis of the nitrogen EFGs and chemical shifts is performed to explain some interesting trends seen experimentally and in the first-principles calculations: (i) (14)N NMR signals for the Pt-coordinating (N(α)) nuclei in the azido ligands are much broader than for the central (N(β)) or terminal (N(γ)) atoms. The N(β) signals are particularly narrow; (ii) compared to N(γ), the N(α) nuclei are particularly strongly shielded; (iii) N(β) nuclei have much larger chemical shifts than N(α) and N(γ) ; and (iv) The Pt-N(α) J-coupling constants are small in magnitude when considering the formal sp hybridization of N(α). It is found that for N(α) a significant shielding reduction due to formation of the dative N(α)-Pt bond is counterbalanced by an increased shielding from spin-orbit (SO) coupling originating at Pt. Upon coordination, the strongly delocalized π system of free azide localizes somewhat on N(β) and N(γ). This effect, along with rehybridization at N(α) upon bond formation with Pt, is shown to cause a deshielding of N(γ) relative to N(α) and a strong increase of the EFG at N(α). The large 2p character of the azide σ bonds is responsible for the particularly high N(β) chemical shifts. The nitrogen s-character of the Pt-N(α) bond is low, which is the reason for the small J-coupling. Similar bonding situations are likely to be found in azide complexes with other transition metals.
Collapse
Affiliation(s)
- Kiplangat Sutter
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA
| | | |
Collapse
|
19
|
Nguyen TH, Arnesano F, Scintilla S, Rossetti G, Ippoliti E, Carloni P, Natile G. Structural Determinants of Cisplatin and Transplatin Binding to the Met-Rich Motif of Ctr1: A Computational Spectroscopy Approach. J Chem Theory Comput 2012; 8:2912-20. [DOI: 10.1021/ct300167m] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Trung Hai Nguyen
- Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany,
and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Fabio Arnesano
- Department Farmaco-Chimico, University of Bari “A. Moro”, via Edoardo
Orabona 4, 70125 Bari, Italy
| | - Simone Scintilla
- Department Farmaco-Chimico, University of Bari “A. Moro”, via Edoardo
Orabona 4, 70125 Bari, Italy
| | - Giulia Rossetti
- Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany,
and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Emiliano Ippoliti
- Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany,
and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Paolo Carloni
- Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany,
and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
- Statistical and Biological Physics Sector, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265,
I-34136 Trieste, Italy
| | - Giovanni Natile
- Department Farmaco-Chimico, University of Bari “A. Moro”, via Edoardo
Orabona 4, 70125 Bari, Italy
| |
Collapse
|
20
|
Farrer NJ, Gierth P, Sadler PJ. Probing platinum azido complexes by 14N and 15N NMR spectroscopy. Chemistry 2011; 17:12059-66. [PMID: 21922574 DOI: 10.1002/chem.201101409] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Indexed: 01/12/2023]
Abstract
Metal azido complexes are of general interest due to their high energetic properties, and platinum azido complexes in particular because of their potential as photoactivatable anticancer prodrugs. However, azido ligands are difficult to probe by NMR spectroscopy due to the quadrupolar nature of (14)N and the lack of scalar (1)H coupling to enhance the sensitivity of the less abundant (15)N by using polarisation transfer. In this work, we report (14)N and (15)N NMR spectroscopic studies of cis,trans,cis-[Pt(N(3))(2)(OH)(2)(NH(3))] (1) and trans,trans,trans-[Pt(N(3))(2)(OH)(2)(X)(Y)], where X=Y=NH(3) (2); X=NH(3), Y=py (3) (py=pyridine); X=Y=py (4); and selected Pt(II) precursors. These studies provide the first (15)N NMR data for azido groups in coordination complexes. We discuss one- and three-bond J((15)N,(195)Pt) couplings for azido and am(m)ine ligands. The (14)N(α) (coordinated azido nitrogen) signal in the Pt(IV) azido complexes is extremely broad (W(1/2)≈2124 Hz for 4) in comparison to other metal azido complexes, attributable to a highly asymmetrical electric field gradient at the (14)N(α) atom. Through the use of anti-ringing pulse sequences, the (14)N NMR spectra, which show resolution of the broad (14)N(α) peak, were obtained rapidly (e.g., 1.5 h for 10 mM 4). The linewidths of the (14)N(α) signals correlate with the viscosity of the solvent. For (15) N-enriched samples, it is possible to detect azido (15)N resonances directly, which will allow photoreactions to be followed by 1D (15)N NMR spectroscopy. The T(1) relaxation times for 3 and 4 were in the range 5.7-120 s for (15)N, and 0.9-11.3 ms for (14)N. Analysis of the (1)J((15)N,(195)Pt) coupling constants suggests that an azido ligand has a moderately strong trans influence in octahedral Pt(IV) complexes, within the series 2-pic<py<NH(3)<Cl(-)<N(3)(-)<NO(2)(-)<SCN(-) (2-pic=2-methylpyridine). In addition, an axial Cl(-) appears to weaken an equatorial Pt(IV)-NH(3) bond to a greater extent than an axial OH(-) ligand.
Collapse
Affiliation(s)
- Nicola J Farrer
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
| | | | | |
Collapse
|