Electronic structure of oxidized complexes derived from cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its photoisomerization mechanism

Nora Planas, Laura Vigara, Clyde Cady, Pere Miró, Ping Huang, Leif Hammarström, Stenbjörn Styring, Nils Leidel, Holger Dau, Michael Haumann, Laura Gagliardi, Christopher J. Cramer, Antoni Llobet

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The geometry and electronic structure of cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its higher oxidation state species up formally to Ru VI have been studied by means of UV-vis, EPR, XAS, and DFT and CASSCF/CASPT2 calculations. DFT calculations of the molecular structures of these species show that, as the oxidation state increases, the Ru-O bond distance decreases, indicating increased degrees of Ru-O multiple bonding. In addition, the O-Ru-O valence bond angle increases as the oxidation state increases. EPR spectroscopy and quantum chemical calculations indicate that low-spin configurations are favored for all oxidation states. Thus, cis-[Ru IV(bpy) 2(OH) 2] 2+ (d 4) has a singlet ground state and is EPR-silent at low temperatures, while cis-[Ru V(bpy) 2(O)(OH)] 2+ (d 3) has a doublet ground state. XAS spectroscopy of higher oxidation state species and DFT calculations further illuminate the electronic structures of these complexes, particularly with respect to the covalent character of the O-Ru-O fragment. In addition, the photochemical isomerization of cis-[Ru II(bpy) 2(H 2O) 2] 2+ to its trans-[Ru II(bpy) 2(H 2O) 2] 2+ isomer has been fully characterized through quantum chemical calculations. The excited-state process is predicted to involve decoordination of one aqua ligand, which leads to a coordinatively unsaturated complex that undergoes structural rearrangement followed by recoordination of water to yield the trans isomer.

Original languageEnglish
Pages (from-to)11134-11142
Number of pages9
JournalInorganic Chemistry
Volume50
Issue number21
DOIs
Publication statusPublished - Nov 7 2011

Fingerprint

Photoisomerization
Electronic structure
electronic structure
Oxidation
oxidation
Discrete Fourier transforms
Paramagnetic resonance
Isomers
Ground state
isomers
Spectroscopy
ground state
Isomerization
Excited states
Molecular structure
spectroscopy
isomerization
molecular structure
fragments
Ligands

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Physical and Theoretical Chemistry

Cite this

Electronic structure of oxidized complexes derived from cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its photoisomerization mechanism. / Planas, Nora; Vigara, Laura; Cady, Clyde; Miró, Pere; Huang, Ping; Hammarström, Leif; Styring, Stenbjörn; Leidel, Nils; Dau, Holger; Haumann, Michael; Gagliardi, Laura; Cramer, Christopher J.; Llobet, Antoni.

In: Inorganic Chemistry, Vol. 50, No. 21, 07.11.2011, p. 11134-11142.

Research output: Contribution to journalArticle

Planas, N, Vigara, L, Cady, C, Miró, P, Huang, P, Hammarström, L, Styring, S, Leidel, N, Dau, H, Haumann, M, Gagliardi, L, Cramer, CJ & Llobet, A 2011, 'Electronic structure of oxidized complexes derived from cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its photoisomerization mechanism', Inorganic Chemistry, vol. 50, no. 21, pp. 11134-11142. https://doi.org/10.1021/ic201686c
Planas, Nora ; Vigara, Laura ; Cady, Clyde ; Miró, Pere ; Huang, Ping ; Hammarström, Leif ; Styring, Stenbjörn ; Leidel, Nils ; Dau, Holger ; Haumann, Michael ; Gagliardi, Laura ; Cramer, Christopher J. ; Llobet, Antoni. / Electronic structure of oxidized complexes derived from cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its photoisomerization mechanism. In: Inorganic Chemistry. 2011 ; Vol. 50, No. 21. pp. 11134-11142.
@article{5a19d6250f3b41f791aa1b88b46a77dc,
title = "Electronic structure of oxidized complexes derived from cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its photoisomerization mechanism",
abstract = "The geometry and electronic structure of cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its higher oxidation state species up formally to Ru VI have been studied by means of UV-vis, EPR, XAS, and DFT and CASSCF/CASPT2 calculations. DFT calculations of the molecular structures of these species show that, as the oxidation state increases, the Ru-O bond distance decreases, indicating increased degrees of Ru-O multiple bonding. In addition, the O-Ru-O valence bond angle increases as the oxidation state increases. EPR spectroscopy and quantum chemical calculations indicate that low-spin configurations are favored for all oxidation states. Thus, cis-[Ru IV(bpy) 2(OH) 2] 2+ (d 4) has a singlet ground state and is EPR-silent at low temperatures, while cis-[Ru V(bpy) 2(O)(OH)] 2+ (d 3) has a doublet ground state. XAS spectroscopy of higher oxidation state species and DFT calculations further illuminate the electronic structures of these complexes, particularly with respect to the covalent character of the O-Ru-O fragment. In addition, the photochemical isomerization of cis-[Ru II(bpy) 2(H 2O) 2] 2+ to its trans-[Ru II(bpy) 2(H 2O) 2] 2+ isomer has been fully characterized through quantum chemical calculations. The excited-state process is predicted to involve decoordination of one aqua ligand, which leads to a coordinatively unsaturated complex that undergoes structural rearrangement followed by recoordination of water to yield the trans isomer.",
author = "Nora Planas and Laura Vigara and Clyde Cady and Pere Mir{\'o} and Ping Huang and Leif Hammarstr{\"o}m and Stenbj{\"o}rn Styring and Nils Leidel and Holger Dau and Michael Haumann and Laura Gagliardi and Cramer, {Christopher J.} and Antoni Llobet",
year = "2011",
month = "11",
day = "7",
doi = "10.1021/ic201686c",
language = "English",
volume = "50",
pages = "11134--11142",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "21",

}

TY - JOUR

T1 - Electronic structure of oxidized complexes derived from cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its photoisomerization mechanism

AU - Planas, Nora

AU - Vigara, Laura

AU - Cady, Clyde

AU - Miró, Pere

AU - Huang, Ping

AU - Hammarström, Leif

AU - Styring, Stenbjörn

AU - Leidel, Nils

AU - Dau, Holger

AU - Haumann, Michael

AU - Gagliardi, Laura

AU - Cramer, Christopher J.

AU - Llobet, Antoni

PY - 2011/11/7

Y1 - 2011/11/7

N2 - The geometry and electronic structure of cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its higher oxidation state species up formally to Ru VI have been studied by means of UV-vis, EPR, XAS, and DFT and CASSCF/CASPT2 calculations. DFT calculations of the molecular structures of these species show that, as the oxidation state increases, the Ru-O bond distance decreases, indicating increased degrees of Ru-O multiple bonding. In addition, the O-Ru-O valence bond angle increases as the oxidation state increases. EPR spectroscopy and quantum chemical calculations indicate that low-spin configurations are favored for all oxidation states. Thus, cis-[Ru IV(bpy) 2(OH) 2] 2+ (d 4) has a singlet ground state and is EPR-silent at low temperatures, while cis-[Ru V(bpy) 2(O)(OH)] 2+ (d 3) has a doublet ground state. XAS spectroscopy of higher oxidation state species and DFT calculations further illuminate the electronic structures of these complexes, particularly with respect to the covalent character of the O-Ru-O fragment. In addition, the photochemical isomerization of cis-[Ru II(bpy) 2(H 2O) 2] 2+ to its trans-[Ru II(bpy) 2(H 2O) 2] 2+ isomer has been fully characterized through quantum chemical calculations. The excited-state process is predicted to involve decoordination of one aqua ligand, which leads to a coordinatively unsaturated complex that undergoes structural rearrangement followed by recoordination of water to yield the trans isomer.

AB - The geometry and electronic structure of cis-[Ru II(bpy) 2(H 2O) 2] 2+ and its higher oxidation state species up formally to Ru VI have been studied by means of UV-vis, EPR, XAS, and DFT and CASSCF/CASPT2 calculations. DFT calculations of the molecular structures of these species show that, as the oxidation state increases, the Ru-O bond distance decreases, indicating increased degrees of Ru-O multiple bonding. In addition, the O-Ru-O valence bond angle increases as the oxidation state increases. EPR spectroscopy and quantum chemical calculations indicate that low-spin configurations are favored for all oxidation states. Thus, cis-[Ru IV(bpy) 2(OH) 2] 2+ (d 4) has a singlet ground state and is EPR-silent at low temperatures, while cis-[Ru V(bpy) 2(O)(OH)] 2+ (d 3) has a doublet ground state. XAS spectroscopy of higher oxidation state species and DFT calculations further illuminate the electronic structures of these complexes, particularly with respect to the covalent character of the O-Ru-O fragment. In addition, the photochemical isomerization of cis-[Ru II(bpy) 2(H 2O) 2] 2+ to its trans-[Ru II(bpy) 2(H 2O) 2] 2+ isomer has been fully characterized through quantum chemical calculations. The excited-state process is predicted to involve decoordination of one aqua ligand, which leads to a coordinatively unsaturated complex that undergoes structural rearrangement followed by recoordination of water to yield the trans isomer.

UR - http://www.scopus.com/inward/record.url?scp=80155150454&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80155150454&partnerID=8YFLogxK

U2 - 10.1021/ic201686c

DO - 10.1021/ic201686c

M3 - Article

VL - 50

SP - 11134

EP - 11142

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 21

ER -