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Unsupported Mg-Alkene Bonding.

ABSTRACT: The first intermolecular early main group metal-alkene complexes were isolated. This was enabled by using highly Lewis acidic Mg centers in the Lewis base-free cations (^Me BDI)Mg⁺ and (^tBu BDI)Mg⁺ with B(C₆ F₅ )₄ ^- counterions (^Me BDI=CH[C(CH₃ )N(DIPP)]₂ , ^tBu BDI=CH[C(tBu)N(DIPP)]₂ , DIPP=2,6-diisopropylphenyl). Coordination complexes with various mono- and bis-alkene ligands, typically used in transition metal chemistry, were structurally characterized for 1,3-divinyltetramethyldisiloxane, 1,5-cyclooctadiene, cyclooctene, 1,3,5-cycloheptatriene, 2,3-dimethylbuta-1,3-diene, and 2-ethyl-1-butene. In all cases, asymmetric Mg-alkene bonding with a short and a long Mg-C bond is observed. This asymmetry is most extreme for Mg-(H₂ C=CEt₂ ) bonding. In bromobenzene solution, the Mg-alkene complexes are either dissociated or in a dissociation equilibrium. A DFT study and AIM analysis showed that the C=C bonds hardly change on coordination and there is very little alkene?Mg electron transfer. The Mg-alkene bonds are mainly electrostatic and should be described as Mg²⁺ ion-induced dipole interactions.

SUBMITTER: Thum K

PROVIDER: S-EPMC7898539 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

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Unsupported Mg-Alkene Bonding.

Thum Katharina K Friedrich Alexander A Pahl Jürgen J Elsen Holger H Langer Jens J Harder Sjoerd S

Chemistry (Weinheim an der Bergstrasse, Germany) 20201223 7

The first intermolecular early main group metal-alkene complexes were isolated. This was enabled by using highly Lewis acidic Mg centers in the Lewis base-free cations (Me BDI)Mg+ and (tBu BDI)Mg+ with B(C6 F5 )4 - counterions (Me BDI=CH[C(CH3 )N(DIPP)]2 , tBu BDI=CH[C(tBu)N(DIPP)]2 , DIPP=2,6-diisopropylphenyl). Coordination complexes with various mono- ...[more]

PMID: 33197075

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Unsupported Mg-Alkene Bonding.

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Unsupported Mg-Alkene Bonding.

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