TY - JOUR
T1 - d–d Dative Bonding Between Iron and the Alkaline-Earth Metals Calcium, Strontium, and Barium
AU - Stegner, Philipp
AU - Färber, Christian
AU - Oetzel, Jan
AU - Siemeling, Ulrich
AU - Wiesinger, Michael
AU - Langer, Jens
AU - Pan, Sudip
AU - Holzmann, Nicole
AU - Frenking, Gernot
AU - Albold, Uta
AU - Sarkar, Biprajit
AU - Harder, Sjoerd
N1 - Publisher Copyright:
© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
PY - 2020/8/17
Y1 - 2020/8/17
N2 - Double deprotonation of the diamine 1,1′-(tBuCH2NH)-ferrocene (1-H2) by alkaline-earth (Ae) or EuII metal reagents gave the complexes 1-Ae (Ae=Mg, Ca, Sr, Ba) and 1-Eu. 1-Mg crystallized as a monomer while the heavier complexes crystallized as dimers. The Fe⋅⋅⋅Mg distance in 1-Mg is too long for a bonding interaction, but short Fe⋅⋅⋅Ae distances in 1-Ca, 1-Sr, and 1-Ba clearly support intramolecular Fe⋅⋅⋅Ae bonding. Further evidence for interactions is provided by a tilting of the Cp rings and the related 1H NMR chemical-shift difference between the Cp α and β protons. While electrochemical studies are complicated by complex decomposition, UV/Vis spectral features of the complexes support Fe→Ae dative bonding. A comprehensive bonding analysis of all 1-Ae complexes shows that the heavier species 1-Ca, 1-Sr, and 1-Ba possess genuine Fe→Ae bonds which involve vacant d-orbitals of the alkaline-earth atoms and partially filled d-orbitals on Fe. In 1-Mg, a weak Fe→Mg donation into vacant p-orbitals of the Mg atom is observed.
AB - Double deprotonation of the diamine 1,1′-(tBuCH2NH)-ferrocene (1-H2) by alkaline-earth (Ae) or EuII metal reagents gave the complexes 1-Ae (Ae=Mg, Ca, Sr, Ba) and 1-Eu. 1-Mg crystallized as a monomer while the heavier complexes crystallized as dimers. The Fe⋅⋅⋅Mg distance in 1-Mg is too long for a bonding interaction, but short Fe⋅⋅⋅Ae distances in 1-Ca, 1-Sr, and 1-Ba clearly support intramolecular Fe⋅⋅⋅Ae bonding. Further evidence for interactions is provided by a tilting of the Cp rings and the related 1H NMR chemical-shift difference between the Cp α and β protons. While electrochemical studies are complicated by complex decomposition, UV/Vis spectral features of the complexes support Fe→Ae dative bonding. A comprehensive bonding analysis of all 1-Ae complexes shows that the heavier species 1-Ca, 1-Sr, and 1-Ba possess genuine Fe→Ae bonds which involve vacant d-orbitals of the alkaline-earth atoms and partially filled d-orbitals on Fe. In 1-Mg, a weak Fe→Mg donation into vacant p-orbitals of the Mg atom is observed.
KW - alkaline-earth metals
KW - ferrocene
KW - metal–metal bonding
KW - theoretical chemistry
UR - http://www.scopus.com/inward/record.url?scp=85087313735&partnerID=8YFLogxK
U2 - 10.1002/anie.202005774
DO - 10.1002/anie.202005774
M3 - 文章
C2 - 32463527
AN - SCOPUS:85087313735
SN - 1433-7851
VL - 59
SP - 14615
EP - 14620
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 34
ER -