Syntheses and crystal structures of vanadium and iron chloride complexes with diglyme.

Saša Petriček,Alojz Demšar

doi:10.17344/acsi.2014.1210

Abstract

A mononuclear molecular complex fac-[VCl3(diglyme)] (1) resulted from the reaction of VCl3 and diglyme (diglyme = di(2-methoxyethyl)ether) in dichloromethane. The violet complex 1 is a sensitive substance which slowly oxidized to a new, blue mononuclear molecular complex, fac-[VOCl2(diglyme)] (2) in the presence of air. The synthesis of iron(II), iron(III) complex [FeCl(diglyme)(THF)]2[FeCl4)]2 (3) was achieved by the reaction of yellow-green, partly oxidized FeCl2.4H2O, diglyme and chlorotrimethyl-silane in tetrahydofuran. The compound consists of the dinuclear cations with octahedral environment of iron(II) and the tetrahedral anions of iron(III). A pure iron(II) chloride-diglyme complex [FeCl2(diglyme)]2 (4) was gained by the reaction of freshly prepared iron(II) chloride hydrate, diglyme and chlorotrimethylsilane in dichloromethane. Diglyme is coordinated in the meridional mode to octahedral iron(II) in dinuclear cations of 3 and in dinuclear molecules 4.

Highlights

Applying a polyether diglyme as a ligand in syntheses of alkaline earth complexes is a common approach to prevent oligomerization by bridging ligands.[1,2,3,4] Saturating a coordination sphere of a metal by the tridentate chelate ligand diglyme hindersmetal – metalcontacts
Minimized intermolecular solid-state interactions in monomeric complexes resulted in an enhanced volatility in comparison to oligomeric complexes, which makes mononuclear alkaline earth complexes superior metal organic chemical vapor deposition (MOCVD) precursors
A prevailingly chelate bonding of digyme to metal centers in complexes is confirmed by the structural data in the CSD listing only about a dozen compounds of alkali metals, aluminum and lead with bridging diglyme molecules among numerous diglyme complexes

Summary

Introduction

Applying a polyether diglyme as a ligand in syntheses of alkaline earth complexes is a common approach to prevent oligomerization by bridging ligands.[1,2,3,4] Saturating a coordination sphere of a metal by the tridentate chelate ligand diglyme hindersmetal – metalcontacts. Minimized intermolecular solid-state interactions in monomeric complexes resulted in an enhanced volatility in comparison to oligomeric complexes, which makes mononuclear alkaline earth complexes superior metal organic chemical vapor deposition (MOCVD) precursors. A prevailingly chelate bonding of digyme to metal centers in complexes is confirmed by the structural data in the CSD (version 5.35 updated May 2014) listing only about a dozen compounds of alkali metals, aluminum and lead with bridging diglyme molecules among numerous diglyme complexes. Diglyme is a flexible O-donor ligand able to coordinate to a whole range of metals; earth alkaline

Methods

Results

Conclusion