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Comparison of the Complexation of Open‐Chain and Cyclic N 2 S 2 Ligands with Cu + and Cu 2+
Author(s) -
Kaden Thomas A.,
Kaderli Susanne,
Sager Wiebke,
SiegfriedHertli Liselotte C.,
Zuberbühler Andreas D.
Publication year - 1986
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19860690529
Subject(s) - chemistry , ligand (biochemistry) , cyclic voltammetry , stoichiometry , chain (unit) , redox , crystallography , stereochemistry , equilibrium constant , absorption spectroscopy , absorption (acoustics) , electrochemistry , inorganic chemistry , electrode , biochemistry , physics , receptor , quantum mechanics , astronomy , acoustics
The complexation properties of the open‐chain N 2 S 2 ligands 1–4 are described and compared to those of analogous N 2 S 2 macrocycles 5–7 . With Cu 2+ , the open‐chain ligands give complexes with the stoichiometry CuL 2+ and CuLOH + , the stabilities and absorption spectra of which have been determined. The ligand field exerted by these ligands is relatively constant and independent of the length of the chain. With Cu + , the species CuLH 2 3+ , CuLH 2+ , and CuL + were identified and their stabilities measured. The redox potentials calculated from the equilibrium constants and measured by cyclic voltammetry agree and lie between 250 and 280 mV against SHE . The comparison between open‐chain and cyclic ligands shows that ( 1 ) a macrocyclic effect is found for Cu 2+ but not for Cu + , ( 2 ) the ligand‐field strength is very different for the two types of ligands, and ( 3 ) the redox potentials span a larger interval for the macrocyclic than for the open‐chain complexes.