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Dicationic E 4 Chains (E=P, As, Sb, Bi) Embedded in the Coordination Sphere of Transition Metals
Author(s) -
Dütsch Luis,
Fleischmann Martin,
Welsch Stefan,
Balázs Gábor,
Kremer Werner,
Scheer Manfred
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201712884
Subject(s) - chemistry , crystallography , electron paramagnetic resonance , zigzag , coordination sphere , dissociation (chemistry) , transition metal , single crystal , stereochemistry , crystal structure , catalysis , geometry , organic chemistry , nuclear magnetic resonance , physics , mathematics
The oxidation chemistry of the complexes [{CpMo(CO) 2 } 2 (μ,η 2 :η 2 ‐E 2 )] (E=P ( A ), As ( B ), Sb ( C ), Bi ( D )) is compared. The oxidation of A – D with [Thia] + (=[C 12 H 8 S 2 ] + ) results in the selective formation of the dicationic E 4 complexes [{CpMo(CO) 2 } 4 (μ 4 ,η 2 :η 2 :η 2 :η 2 ‐E 4 )] 2+ (E=P ( 1 ), As ( 2 ), Sb ( 3 ), Bi ( 4 )), stabilized by four [CpMo(CO) 2 ] fragments. The formation of the corresponding monocations [ A ] + , [ C ] + , and [ D ] + could not be detected by cyclic voltammetry, EPR, or NMR spectroscopy. This finding suggests that dimerization is fast and that there is no dissociation in solution, which was also predicted by DFT calculations. However, EPR measurements of 2 confirmed the presence of small amounts of the radical cation [ B ] + in solution. Single‐crystal X‐ray diffraction revealed that the products 1 and 2 feature a zigzag E 4 chain in the solid state while 3 and 4 bear a central E 4 cage with a distorted “butterfly‐like” geometry. Additionally, 1 can be easily and reversibly converted into a symmetric and an unsymmetric form.