In:
European Journal of Inorganic Chemistry, Wiley, Vol. 2010, No. 18 ( 2010-06), p. 2813-2825
Abstract:
A wide range of reactive trivalent and divalent rare earth thiocyanate complexes with 1,2‐dimethoxyethane (dme), tetrahydrofuran (thf) and acetonitrile namely [RE(NCS) 3 (dme) 3 ] [RE = La ( 1a ), Nd ( 1b )], [RE(NCS) 3 (dme) 2 (μ‐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 ] · 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 (μ‐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 dme 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 η 1 :η 1 ‐( O , O ′)‐dme and 1f is 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 Å 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 ≈ 149°) SCN–RE–NCS bonding is observed in rac ‐ 4a – c and Λ‐ 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.
Type of Medium:
Online Resource
ISSN:
1434-1948
,
1099-0682
DOI:
10.1002/ejic.v2010:18
DOI:
10.1002/ejic.201000111
Language:
English
Publisher:
Wiley
Publication Date:
2010
detail.hit.zdb_id:
1475009-0
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