Crystal structure of dimethylformamide-diethanolateamine-dioxo-molybdenum( VI), MoO2[O(CH2)2NH(CH2)2O][(CH3)2NCHO]

Abstract

Source of material Experimental detailsHydrogen atoms were attached atidealized positions on carbon atoms with U iso related to the U eq of the parent atoms and were refined with the riding model. H100 bound to secondary amine nitrogen N1wasfound and refined freely. DiscussionDiethanolateamine is awell-known and widelyused ligand system and its dioxomolybdenum compound hasbeen studied thoroughly [1]. Toour surprise no crystalstructure of this complex or any related molybdenum diethanolateamine complex wasp ublished so faralthough severalcomplexes of this ligand with other transition and main group metals are structurally characterized [2][3][4][5][6][7].The title complex consists of adiscretem ononuclearu nit, in which the diethanolateamine is coordinated to the molybdenum atom asatridentate ligand to form two five-memberedrings. Two oxo ligands coordinate to the metalt of orm astable cis-dioxomolybdenum(VI)core. ADMFmolecule trans to one oxo group completes the distorted octahedralcoordination sphere. Again this is in the range of analogous complexes with the MoO 2 2+ core (2.28 Å-2.50 Å) [11]. The length of the Mo-O5 bond is 2.438(2) Åwhich is rather long, implying avery weak bonding interaction between the molybdenum and the DMFmolecule. This coordination nevertheless allows to obtain astable distorted octahedralenvironment. The Mo-O(DMF)distance is longer thanMo-Odistances formed by other solvent molecules e.g. MeOH with 2.289 Å-2.385 Å [8,12] or H 2 Owith2.255 Å-2.293 Å [13]. The comparably weakb onding interaction indicates thatDMFis particularly easy to remove from the molecule. The most evident distortionsofthe structure from the idealized octahedralenvironment are defined by the N1-Mo-O1(75.81(7)°), N1-Mo-O2( 74.97(7)°) and O1-Mo-O2( 146.43(7)°) angles. With the strain of two five-memberedchelate rings, two alkoxy groups are bent towards the nitrogen atom.