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Taylor MG, Yang T, Lin S, Nandy A, Janet JP, Duan C, Kulik HJ. Seeing Is Believing: Experimental Spin States from Machine Learning Model Structure Predictions. J Phys Chem A 2020; 124:3286-3299. [PMID: 32223165 PMCID: PMC7311053 DOI: 10.1021/acs.jpca.0c01458] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
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Determination of ground-state spins
of open-shell transition-metal
complexes is critical to understanding catalytic and materials properties
but also challenging with approximate electronic structure methods.
As an alternative approach, we demonstrate how structure alone can
be used to guide assignment of ground-state spin from experimentally
determined crystal structures of transition-metal complexes. We first
identify the limits of distance-based heuristics from distributions
of metal–ligand bond lengths of over 2000 unique mononuclear
Fe(II)/Fe(III) transition-metal complexes. To overcome these limits,
we employ artificial neural networks (ANNs) to predict spin-state-dependent
metal–ligand bond lengths and classify experimental ground-state
spins based on agreement of experimental structures with the ANN predictions.
Although the ANN is trained on hybrid density functional theory data,
we exploit the method-insensitivity of geometric properties to enable
assignment of ground states for the majority (ca. 80–90%) of
structures. We demonstrate the utility of the ANN by data-mining the
literature for spin-crossover (SCO) complexes, which have experimentally
observed temperature-dependent geometric structure changes, by correctly
assigning almost all (>95%) spin states in the 46 Fe(II) SCO complex
set. This approach represents a promising complement to more conventional
energy-based spin-state assignment from electronic structure theory
at the low cost of a machine learning model.
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Affiliation(s)
- Michael G Taylor
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Tzuhsiung Yang
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Sean Lin
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Aditya Nandy
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jon Paul Janet
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Chenru Duan
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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LeBlond T, Dinolfo PH. Density Functional Theory Prediction of the Electrocatalytic Mechanism of Proton Reduction by a Dicobalt Tetrakis(Schiff Base) Macrocycle. Inorg Chem 2020; 59:3764-3774. [PMID: 32133844 DOI: 10.1021/acs.inorgchem.9b03411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A dicobalt tetrakis(Schiff base) macrocycle has recently been reported to electrochemically catalyze the reduction of H+ to H2 in an acetonitrile solution. Density functional theory (DFT) calculations using the ωB97X-D functional are shown to produce structural and thermodynamic results in good agreement with the experimental data. A mechanistic model based on thermodynamics is developed that incorporates electrochemical and magnetic details of the complex, accounting for electron-spin reorganization of the metal center after redox steps. The model is validated through a comparison of the predicted electrochemical potentials with the irreversible cyclic voltammogram of [Co2LAc]+, which shows redox-coupled spin-crossover (RCSCO) behavior for the CoII/III transitions. Using our model, we predict the thermodynamically favored mechanism of H2 evolution by [Co2L]2+ to be one of heterolytic proton attack on a [CoII2L(μ-H)]+ species. Understanding the electronic details and thermodynamically preferred mechanism of this catalyst will aid in improving its efficiency and the future design of bimetallic Co-based H+ electrocatalysts. Also, this work will assist in the future DFT modeling of bimetallic RCSCO complexes.
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Affiliation(s)
- Tyler LeBlond
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 125 Cogswell Laboratory, 110 Eighth Street, Troy, New York 12180, United States
| | - Peter H Dinolfo
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 125 Cogswell Laboratory, 110 Eighth Street, Troy, New York 12180, United States
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Nandy A, Chu DBK, Harper DR, Duan C, Arunachalam N, Cytter Y, Kulik HJ. Large-scale comparison of 3d and 4d transition metal complexes illuminates the reduced effect of exchange on second-row spin-state energetics. Phys Chem Chem Phys 2020; 22:19326-19341. [DOI: 10.1039/d0cp02977g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The origin of distinct 3d vs. 4d transition metal complex sensitivity to exchange is explored over a large data set.
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Affiliation(s)
- Aditya Nandy
- Department of Chemical Engineering
- Massachusetts Institute of Technology
- Cambridge
- USA
- Department of Chemistry
| | - Daniel B. K. Chu
- Department of Chemical Engineering
- Massachusetts Institute of Technology
- Cambridge
- USA
| | - Daniel R. Harper
- Department of Chemical Engineering
- Massachusetts Institute of Technology
- Cambridge
- USA
- Department of Chemistry
| | - Chenru Duan
- Department of Chemical Engineering
- Massachusetts Institute of Technology
- Cambridge
- USA
- Department of Chemistry
| | - Naveen Arunachalam
- Department of Chemical Engineering
- Massachusetts Institute of Technology
- Cambridge
- USA
| | - Yael Cytter
- Department of Chemical Engineering
- Massachusetts Institute of Technology
- Cambridge
- USA
| | - Heather J. Kulik
- Department of Chemical Engineering
- Massachusetts Institute of Technology
- Cambridge
- USA
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Cirera J, Ruiz E. Electronic and Steric Control of the Spin-Crossover Behavior in [(CpR)2Mn] Manganocenes. Inorg Chem 2017; 57:702-709. [DOI: 10.1021/acs.inorgchem.7b02592] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jordi Cirera
- Departament de
Química Inorgànica i Orgànica and Institut de
Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Eliseo Ruiz
- Departament de
Química Inorgànica i Orgànica and Institut de
Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
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Ioannidis EI, Kulik HJ. Ligand-Field-Dependent Behavior of Meta-GGA Exchange in Transition-Metal Complex Spin-State Ordering. J Phys Chem A 2017; 121:874-884. [DOI: 10.1021/acs.jpca.6b11930] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Efthymios I. Ioannidis
- Department
of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Heather J. Kulik
- Department
of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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