Synthesis and structure of DyIII 2,2-bis[2-(dimethylamino)-5-methylphenyl]acetate complexes

2,2-Bis[2-(dimethylamino)-5-methylphenyl]acetic acid, Ar 2 CHCOOH ( 1 ) (Ar = 5-Me-2-Me 2 NC 6 H 3 ), was synthesized by the carboxylation of s[2-(dimethylamino)-5-methylphenyl]-methyl lithium, [Ar 2 CH]Li(TMEDA), with gaseous CO 2 . The reaction of 1 with the cationic bis(alkyl) complex [(Me 3 SiCH 2 ) 2 Dy(THF) n ][BPh 4 ] (2: 1 molar ratio) unexpectedly afforded the tetracarboxylate complex [Dy(O 2 CCHAr 2 ) 4 (Et 2 NH 2 ) 2 ][BPh 4 ] ( 3 ), whereas the trinuclear oxo cluster [Dy 3 O(O 2 CHAr 2 ) 6 (THF) 4 ][BPh 4 ] ( 4 ) was prepared from [( o -Me 2 NC 6 H 4 CH 2 ) 2 -Dy(THF) n ][BPh 4 ]. In complex 4 , three Dy 3+ cations are linked by the μ 3 -oxo oxygen atom and six bridging μ 2 -κ 1 -O:κ 1 -O’-carboxylate ligands. According to the X-ray diffraction data, NMe 2 groups of the diphenylmethanide moiety are not coordinated to Dy 3+ cations in complexes 3 and 4 .