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Mixed Copper–Lanthanide Metallomesogens
Author(s) -
Binnemans Koen,
Lodewyckx Katleen,
Donnio Bertrand,
Guillon Daniel
Publication year - 2002
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20020301)8:5<1101::aid-chem1101>3.0.co;2-9
Subject(s) - lanthanide , copper , materials science , chemistry , metallurgy , organic chemistry , ion
This paper describes the first examples of heteropolynuclear metallomesogens that contain both a transition metal ion and a trivalent lanthanide ion. Adducts were formed between a mesomorphic [Cu(salen)] complex (salen=2,2′‐ N , N ′‐bis(salicylidene)ethylenediamine) with six terminal tetradecyloxy chains and a lanthanide nitrate (Ln=La, Gd). Different stoichiometries were found, depending on the lanthanide ion: a trinuclear copper–lanthanum–copper complex [La(NO 3 ) 3 {Cu(salen)} 2 ] and a binuclear copper‐gadolinium complex [Gd(NO 3 ) 3 Cu(salen)]. The compounds exhibit a hexagonal columnar mesophase (Col H ) over a wide temperature‐range with rather low melting temperatures. Although the clearing point could be observed for the parent [Cu(salen)] complex, the mixed f–d complexes decomposed in the high‐temperature part of the mesomorphic domain before clearing. On the basis of X‐ray diffraction measurements and molecular modelling, a structural model for the mesophase of the metal complexes is proposed.