Chemisorption of exchange-coupled [Ni2L(dppba)]+ complexes on gold by using ambidentate 4-(Diphenylphosphino)benzoate co-ligands
A new strategy for the fixation of redox-active dinickel(II) complexes with high-spin ground states to gold surfaces was developed. The dinickel(II) complex [Ni2L(Cl)]ClO4 (1ClO4), in which L2− represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, reacts with ambidentate 4-(diphenylph...
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| Hauptverfasser: | , , , , , , , , , , , , , , , , , , , , , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
17 April 2013
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| In: |
Chemistry - a European journal
Year: 2013, Jahrgang: 19, Heft: 24, Pages: 7787-7801 |
| ISSN: | 1521-3765 |
| DOI: | https://doi.org/10.1002/chem.201300496 |
| Online-Zugang: | Verlag, lizenzpflichtig, Volltext: https://doi.org/https://doi.org/10.1002/chem.201300496 Verlag, lizenzpflichtig, Volltext: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.201300496 |
| Verfasserangaben: | Matthias Golecki, Jochen Lach, Alexander Jeremies, Frank Lungwitz, Michael Fronk, Georgeta Salvan, Dietrich R.T. Zahn, Jaena Park, Yulia Krupskaya, Vladislav Kataev, Rüdiger Klingeler, Bernd Büchner, Benjamin Mahns, Martin Knupfer, Pablo F. Siles, Daniel Grimm, Oliver G. Schmidt, Andreas Reis, Werner R. Thiel, Daniel Breite, Bernd Abel, and Berthold Kersting |
| Zusammenfassung: | A new strategy for the fixation of redox-active dinickel(II) complexes with high-spin ground states to gold surfaces was developed. The dinickel(II) complex [Ni2L(Cl)]ClO4 (1ClO4), in which L2− represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, reacts with ambidentate 4-(diphenylphosphino)benzoate (dppba) to form the carboxylato-bridged complex [Ni2L(dppba)]+, which can be isolated as an air-stable perchlorate [Ni2L(dppba)]ClO4 (2ClO4) or tetraphenylborate [Ni2L(dppba)]BPh4 (2BPh4) salt. The auration of 2ClO4 was probed on a molecular level, by reaction with AuCl, which leads to the monoaurated NiII2AuI complex [NiII2L(dppba)AuICl]ClO4 (3ClO4). Metathesis of 3ClO4 with NaBPh4 produces [NiII2L(dppba)AuIPh]BPh4 (4BPh4), in which the Cl− is replaced by a Ph− group. The complexes were fully characterized by ESI mass spectrometry, IR and UV/Vis spectroscopy, X-ray crystallography (2BPh4 and 4BPh4), cyclic voltammetry, SQUID magnetometry and HF-ESR spectroscopy. Temperature-dependent magnetic susceptibility measurements reveal a ferromagnetic coupling J=+15.9 and +17.9 cm−1 between the two NiII ions in 2ClO4 and 4BPh4 (H=−2 JS1S2). HF-ESR measurements yield a negative axial magnetic anisotropy (D<0), which implies a bistable (easy axis) magnetic ground state. The binding of the [Ni2L(dppba)]ClO4 complex to gold was ascertained by four complementary surface analytical methods: contact angle measurements, atomic-force microscopy, X-ray photoelectron spectroscopy, and spectroscopic ellipsometry. The results indicate that the complexes are attached to the Au surface through coordinative AuP bonds in a monolayer. |
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| Beschreibung: | Gesehen am 17.02.2020 Im Titel ist die Zahl "2" tiefgestellt und das Pluszeichen hochgestellt |
| Beschreibung: | Online Resource |
| ISSN: | 1521-3765 |
| DOI: | https://doi.org/10.1002/chem.201300496 |