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Synthesis, Characterization and Electrochemical Properties of Optically Active [60]Fullerene Organotransition Metal Complexes mer ‐[(η 2 ‐C 60 )M(CO) 3 {(−)‐DIOP}] (M = Mo, W), mer ‐[(η 2 ‐C 60 )M(CO) 3 {(+)‐DIOP}] (M = Mo, W) and [(η 2 ‐C 60 )M{(−)‐DIOP}] (M = Pd, Pt) − Crystal Structure of [(η 2 ‐C 60 )Pt{(−)‐DIOP}]
Author(s) -
Song LiCheng,
Liu PengChong,
Liu JinTing,
Su FuHai,
Wang GuangFeng,
Hu QingMei,
Zanello Piero,
Laschi Franco,
Fontani Marco
Publication year - 2003
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200300106
Subject(s) - chemistry , ligand (biochemistry) , electron paramagnetic resonance , electrochemistry , crystallography , metal , dichloromethane , chlorobenzene , butane , circular dichroism , fullerene , stereochemistry , catalysis , organic chemistry , biochemistry , physics , receptor , electrode , nuclear magnetic resonance , solvent
Abstract This paper reports on several new optically active organometallic [60]fullerene complexes that contain a chiral (+)‐DIOP or (−)‐DIOP ligand [DIOP = 2,3‐ O , O′ ‐isopropylidene‐2,3‐dihydroxy‐1,4‐bis(diphenylphosphanyl)butane]. The Mo/W complexes mer ‐[(η 2 ‐C 60 )M(CO) 3 {(−)‐DIOP}] ( 1 , M = Mo; 2 , M = W) and mer ‐[(η 2 ‐C 60 )M(CO) 3 {(+)‐DIOP}] ( 3 , M = Mo; 4 , M = W) were synthesized by a photochemical reaction of a mixture of [M(CO) 6 ], (−)‐DIOP or (+)‐DIOP and C 60 in chlorobenzene in 42−51% yields, whereas the Pd/Pt complexes [(η 2 ‐C 60 )M{(−)‐DIOP}] ( 5 , M = Pd; 6 , M = Pt) were prepared by a thermal reaction of C 60 with [M(PPh 3 ) 4 ], followed by in situ treatment of the intermediate [(η 2 ‐C 60 )M(PPh 3 ) 2 ] with (−)‐DIOP, in toluene in > 90% yields. All the new complexes 1 − 6 were fully characterized by elemental analysis, 1 H ( 31 P, 13 C) NMR, IR, UV/Vis and circular dichroism (CD) spectroscopy. The structure of [(η 2 ‐C 60 )Pt{(−)‐DIOP}] ( 6 ) was further confirmed by X‐ray diffraction techniques. The electrochemical properties of complexes 1 , 2 , 5 and 6 were studied in dichloromethane solution. Complexes 1 and 2 display the reversible, four‐membered, one‐electron reduction sequence typical of fullerene ligands, as well as the reversible (in the cyclic voltammetric time scale) one‐electron oxidation of the outer metal fragment. Complexes 5 and 6 are less stable to the same electron transfer processes. EPR measurements suggest that in the different electrogenerated monoanions, the added electrons enter the LUMO orbitals partially contributed by the metal fragment. In addition, they confirm that the instability of the reduction intermediates is due to the release of free C 60 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)