Butcher RJ, Purdy AP. μ-Methyl-ene-bis-[di-bromido(diethyl ether-κ
O)aluminium(III)]: crystal structure and chemical exchange in solution.
ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS 2021;
77:647-652. [PMID:
34164145 PMCID:
PMC8183446 DOI:
10.1107/s2056989021005302]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/19/2021] [Indexed: 11/12/2022]
Abstract
The crystal structure of μ-methylene-bis[(dibromo)(diethyl ether-κO)aluminium(III)] has established that the Al—CH2—Al angle, 118.4 (2)°, is the smallest observed for structure where this moiety is not part of a ring.
In the title compound, [Al2Br4(CH2)(C4H10O)2], the molecule lies on a crystallographic twofold axis passing through the bridging C atom. Each AlIII atom is four-coordinate, being bonded to two bromide ions, bridging the CH2 group as well as the oxygen atom of a diethyl ether ligand in a slightly distorted tetrahedral arrangement with angles ranging from 101.52 (8) to 116.44 (5)°. The Al—CH2—Al angle, 118.4 (2)°, is the smallest observed for a structure where this moiety is not part of a ring. In the crystal, weak C—H⋯Br interactions, characterized as R22(12) rings, link the molecules into ribbons in the [101] direction. The title compound is monomeric and coordinatively saturated in the solid state, as each aluminum is four-coordinate, but in solution the ether molecules from either or both Al atoms can dissociate, and would be expected to rapidly exchange, and this is supported by NMR data.
Collapse