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The First Thioallenylidene Complexes from Ruthenium‐Butatrienylidene Intermediates
Author(s) -
Winter Rainer F.
Publication year - 1999
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/(sici)1099-0682(199912)1999:12<2121::aid-ejic2121>3.0.co;2-m
Subject(s) - chemistry , ruthenium , heteroatom , cumulene , electron paramagnetic resonance , electrochemistry , ligand (biochemistry) , metal , resonance (particle physics) , homo/lumo , carbon fibers , stereochemistry , photochemistry , molecule , organic chemistry , catalysis , ring (chemistry) , biochemistry , physics , receptor , materials science , electrode , nuclear magnetic resonance , particle physics , composite number , composite material
Ruthenium‐butatrienylidene cations trans‐ [Cl(L 2 ) 2 Ru=C=C=C=CH 2 ] + are key intermediates in the synthesis of the first thioallenylidene complexes trans‐ [Cl(L 2 ) 2 Ru=C=C=C(SR)R′] + (L 2 = dppm, R = Et, R′ = Me: 3a , L 2 = dppm, R = Me, R′ = C 4 H 7 : 3b , L 2 = dppe, R = C 3 H 5 , R′ = C 4 H 7 : 3c ). Spectroscopic and electrochemical data for 3a–c are presented and are compared with those of their aminoallenylidene analogues. Aminoallenylidene complexes are best represented by the iminiumalkynyl resonance form, while a true cumulene description is much more appropriate for thioallenylidene complexes 3a–c . Based on a combination of spectroscopic and electrochemical data, we present evidence that the NMR shifts of the carbon atoms of the unsaturated ligand in these allenylidene complexes are correlated to the HOMO–LUMO gap. In situ EPR‐, UV/Vis‐, and IR‐spectro‐electrochemistry reveals that the one‐electron oxidation occurs at the metal center, while reduction occurs at the carbon–heteroatom terminus.