A Structural Investigation of Trivalent and Divalent Rare Earth Thiocyanate Complexes Synthesised by Redox Transmetallation

作者：Bakker Jacinta M; Deacon Glen B^*; Forsyth Craig M; Junk Peter C; Wiecko Michal

来源：European Journal of Inorganic Chemistry, 2010, (18): 2813-2825.

DOI：10.1002/ejic.201000111

• Rare earths
• N ligands
• Ether ligands
• Redox chemistry
• Transmetallation
• Solid-state structures

A wide range of reactive trivalent and divalent rare earth thiocyanate complexes with 1,2-dimethoxyethane (dime), tetrahydrofuran (thf) and acetonitrile namely [RE(NCS)(3)(dme)(3)] [RE = La (1a), Nd (1b)], [RE(NCS)(3)(dme)(2)(mu-dme)(0.5)](2) [RE = Dy (1d), Er (1e)], [RE(NCS)(3)(thf)(4)](2) [RE = Y (3a), La (3b), Nd (3c), Sm (3d), Dy (3e), Ho (3f)], [Ca(NCS)(2)(dme)(3)] [rac-(4a)], [RE(NCS)(2)(dme)(3)] (RE = Sm (rac-4b), Eu (rac-4c), [Ca(Yb)(NCS)(2)(NCMe)(5)]center dot NCMe [Ca (6a), Yb (6b)], and [Eu(NCS)(2)(thf)(4)](2) (7) have been prepared in good to high yield by redox transmetallation between rare earth metals and the commercially available Hg(SCN)(2). In addition [Eu(NCS)(3)(dme)(2)(mu-dme)(0.5)](2) (1c) and [Yb(NCS)(3)(dme)(2)] (1f) have been prepared by oxidation of rac-4c and [Yb(NCS)(2)(thf)(2)], respectively, with Hg(SCN)(2) in dme. Crystallisation of 1e from dme/diglyme (diglyme = bis(2-methoxyethyl) ether) and thf yields [Er(NCS)(3)(diglyme)(dme)] (2) and [Er(NCS)(3)(thf)(4)](2) (3g), respectively, and prolonged storage of rac-4a in cold dime gave [Ca(NCS)(2)(dme)(2)(H(2)O)] (5). All undergo rapid hydrolysis on exposure to air. Two structural breaks are observed for [RE(NCS)(3)(dme)(n)] complexes, all of which have solely RE-NCS binding. Compounds 1a,b are nine-coordinate monomers that differ in the arrangement (T or Y) of the RE(NCS)(3) moiety, 1c-e are eight coordinate dinuclear complexes being bridged by a single eta(1):eta(1)-(O,O')-dme and ills a seven coordinate monomer. 2 is an eight coordinate monomer with, unusually for the present complexes, a facial RE(NCS)(3) array. By contrast 3a-g are all dimeric, eight coordinate complexes with two unusual RE-NCS-RE bridges. The RE-S bonds are very weak and show little variation with RE(3+) radius, and Er-S of 3g increases by 0.18 angstrom between 123 K and room temperature), foreshadowing a change to a seven coordinate monomer with [Yb(NCS)(3)(thf)(4)]. Monomeric eight coordination with transoid (N-RE-N approximate to 149 degrees) SCN-RE-NCS bonding is observed in rac-4a-c and Lambda-4c, whilst 5 is a seven-coordinate monomer with a cis-Ca-(NCS)(2) array. Single crystals of 6,a,b contain seven-coordinate, pentagonal bipyramidal monomers with trans-NCS ligands, whereas 7 is dimeric with two Eu-NCS-Eu bridging ligands and seven coordination for Eu.

• 出版日期2010-6