1446342-19-3Relevant academic research and scientific papers
Chemisorption of exchange-coupled [Ni2L(dppba)]+ complexes on gold by using ambidentate 4-(diphenylphosphino)benzoate Co-ligands
Golecki, Matthias,Lach, Jochen,Jeremies, Alexander,Lungwitz, Frank,Fronk, Michael,Salvan, Georgeta,Zahn, Dietrich R. T.,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
, p. 7787 - 7801 (2013/07/27)
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 L 2- 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 Ni II2AuI complex [NiII 2L(dppba)AuICl]ClO4 (3ClO4). Metathesis of 3ClO4 with NaBPh4 produces [Ni II2L(dppba)AuIPh]BPh4 (4BPh 4), 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 4BPh 4), 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 Ni II ions in 2ClO4 and 4BPh4 (H=-2 JS 1S2). HF-ESR measurements yield a negative axial magnetic anisotropy (Da 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 Au-P bonds in a monolayer. Copyright
