Chemisorption of Exchange-Coupled [Ni sub(2)L(dppba)] super(+) 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 [Ni sub(2)L(Cl)]ClO sub(4) (1ClO sub(4)), in which L super(2-) represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, reacts with...

Full description

Saved in:
Bibliographic Details
Published in:Chemistry : a European journal 2013-06, Vol.19 (24), p.7787-7801
Main Authors: Golecki, Matthias, Lach, Jochen, Jeremies, Alexander, Lungwitz, Frank, Fronk, Michael, Salvan, Georgeta, Zahn, DietrichRT, Park, Jaena, Krupskaya, Yulia, Kataev, Vladislav, Klingeler, Ruediger, Buechner, Bernd, Mahns, Benjamin, Knupfer, Martin, Siles, Pablo F, Grimm, Daniel, Schmidt, Oliver G, Reis, Andreas, Thiel, Werner R, Breite, Daniel, Abel, Bernd, Kersting, Berthold
Format: Article
Language:English
Subjects:
Chemisorption
Contact angle
Gold
Ground state
Hafnium
Spectroscopy
Surface chemistry
X-rays
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 [Ni sub(2)L(Cl)]ClO sub(4) (1ClO sub(4)), in which L super(2-) represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, reacts with ambidentate 4-(diphenylphosphino)benzoate (dppba) to form the carboxylato-bridged complex [Ni sub(2)L(dppba)] super(+), which can be isolated as an air-stable perchlorate [Ni sub(2)L(dppba)]ClO sub(4) (2ClO sub(4)) or tetraphenylborate [Ni sub(2)L(dppba)]BPh sub(4) (2BPh sub(4)) salt. The auration of 2ClO sub(4) was probed on a molecular level, by reaction with AuCl, which leads to the monoaurated Ni super(II) sub(2)Au super(I) complex [Ni super(II) sub(2)L(dppba)Au super(I)Cl]ClO sub(4) (3ClO sub(4)). Metathesis of 3ClO sub(4) with NaBPh sub(4) produces [Ni super(II) sub(2)L(dppba)Au super(I)Ph]BPh sub(4) (4BPh sub(4)), in which the Cl super(-) is replaced by a Ph super(-) group. The complexes were fully characterized by ESI mass spectrometry, IR and UV/Vis spectroscopy, X-ray crystallography (2BPh sub(4) and 4BPh sub(4)), cyclic voltammetry, SQUID magnetometry and HF-ESR spectroscopy. Temperature-dependent magnetic susceptibility measurements reveal a ferromagnetic coupling J=+15.9and +17.9cm super(-1) between the two Ni super(II) ions in 2ClO sub(4) and 4BPh sub(4) (H=-2JS sub(1)S sub( 2)). HF-ESR measurements yield a negative axial magnetic anisotropy (D
ISSN:0947-6539
1521-3765
DOI:10.1002/chem.201300496