Four structural classes have been established for rare earth anthranilates, which have been prepared from the lanthanoid chloride or triflate and anthranilic acid (anthH) followed by pH adjustment to 4. [La(anth)3]n is a polymeric complex with nine coordinate lanthanum and bridging tridentate (O,O,O′) anthranilate ligands, whereas [Nd(anth)3(H2O)3] · 3H2O is monomeric with nine coordinate neodymium and solely chelating (O,O) anthranilate groups. Both chelating (O,O) and bridging bidentate (O,O′) ligands are observed in dimeric [Er2(anth)6(H2O)4] · 2H2O, in which erbium is eight coordinate and the water ligands are in a trans arrangement. A polymer is observed for [Yb(anth)3(H2O)]n with solely bridging bidentate (O,O′) ligands and seven coordination for ytterbium. The NH2 groups of the anthranilate ligands are not coordinated to the metal but is unusually involved in hydrogen-bond networks with water molecules for Ln = Er, Yb.
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039999 Chemical Sciences not elsewhere classified
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970103 Expanding Knowledge in the Chemical Sciences