Premium
Electronic Communications Mediated by Metal Clusters
Author(s) -
Yip John H. K.,
Wu Jianguo,
Wong KwokYin,
Ho Kam Piu,
Pun Christine SoNgan,
Vittal Jagadese J.
Publication year - 2004
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200400180
Subject(s) - chemistry , comproportionation , metal , electronic communication , crystallography , valence (chemistry) , cyclic voltammetry , bond length , single crystal , intramolecular force , stereochemistry , electrochemistry , crystal structure , electrode , telecommunications , organic chemistry , computer science
Abstract Two model systems [Cu I 3 (dppm) 3 (μ 3 ‐η 1 ‐C≡CFc) 2 ]•PF 6 ( 1 •PF 6 ) and [Pt I 2 (dppm) 2 (C=CFc) 2 ] ( 2 ) were devised to probe the ability of metal clusters in mediating electronic communications. The complexes were characterized by using single‐crystal X‐ray diffraction, UV‐vis spectroscopy, and voltammetry (dppm = bis(diphenylphosphino)methane; Fc = ferrocenyl). The complex is composed a of trimetallic Cu I 3 core bridged by three dppm and capped with one and two ferrocenylacetylides, respectively. Cyclic and differential pulse voltammograms of 1 •PF 6 show two reversible Fc oxidations separated by 110 ± 14 mV, giving a comproportionation constant K c of 77 ± 30. The stability of the mixed‐valence complex 1 2+ arises mainly from the reduction of electrostatic repulsion and statistical distribution. On the other hand, the Pt‐Pt σ‐bond enhances electronic interactions between the terminal Fc‐groups in compound 2 . The CV of the complex shows two reversible Fc‐centered oxidations which are separated by 267 ± 14 mV and the K c is 3.3 × 10 4 ± 1.5 × 10 4 . Addition of a d 10 AuCl/Br fragment to the Pt‐Pt bond gives rise to complexes [Pt 2 (μ‐AuX)(dppm) 2 (C≡CFc) 2 ] [X = Cl ( 3 ) and Br ( 4 )]. The two Fc‐oxidations are not resolved in the CV of the complexes, indicating that the electronic communication is shut down.